# A Transition to Sustainable Housing

Progress and Prospects for a Low Carbon Housing Future

Trivess Moore · Andréanne Doyon

A Transition to Sustainable Housing

# Trivess Moore • Andréanne Doyon A Transition to Sustainable Housing

Progress and Prospects for a Low Carbon Housing Future

Trivess Moore RMIT University Melbourne, VIC, Australia Andréanne Doyon Simon Fraser University Burnaby, BC, Canada

ISBN 978-981-99-2759-3 ISBN 978-981-99-2760-9 (eBook) https://doi.org/10.1007/978-981-99-2760-9

© Te Editor(s) (if applicable) and Te Author(s) 2023

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# **Foreword**

*A transition to sustainable housing* makes for accessible, important reading as we face into the climate emergency. Te authors, based on contrasting climates and global regions, methodically set out a consistent and wellargued call to action, sprinkled with examples that illustrate the urgency about what needs to be done. Torough referencing throughout makes this a go-to text, not only for academics and students, but also for a wide range of actors, policy makers, commentators, and interested publics.

Te book posits a set of contrasting and often competing/oppositional observations as explanations for (a) why the sustainable housing crisis is even greater than it often appears and (b) why responses are inadequate. Tus, Chap. 1 articulates the juxtaposition of the housing and climate crises and sketches some key elements of the predicament. Chapter 2 draws upon the concept of housing markets, and, specifcally, ways in which they fail to deliver on human needs. Alluding to the disconnect between the theory of utility and the idea of sustainable housing as a basic right, the authors explore through the language of building codes, planning systems, and related regulatory mechanisms how markets mediation has largely failed to deliver sufcient shifts towards sustainable housing.

Drawing on the observation that housing occupies (unique) land parcels, and often lasts for 100 years or more, Chap. 3 outlines some ramifcations of this for the housing sustainability agenda. Namely, housing might better be seen as social infrastructure rather than private asset, and decisions made around design, materials, technologies, and construction methods are critical for determining a dwelling's quality and performance outcomes and how it will be used by multiple households over a long life. Moreover, putting things right once dwellings are hastily built for an initial occupier is expensive or even impossible. For example, poor dwelling orientation is hard to fx.

Drawing upon their extensive experience working on practical projects evaluating energy efciency retroft, the authors present a reasoned case explaining how energy efcient retroft seems feasible and logical and yet has not happened and is not happening at anything like the necessary rate. Tey also point to the ways in which housing sustainability presents diferent problems at varying scales, including the dwelling scale, neighbourhood and city scale and the state, national, and international scale. Another focus for the book draws on the authors' previous work on the rapidly growing corpus of work on socio-technical transitions. Adopting a neutral position, they probe concepts of transitions by expanding on key aspects of the housing and climate emergency debate. Te nonlinearity of change is a particular focus, as is the multiplicity of competing and often conficting priorities facing a transition to sustainable and universal housing.

Te fnal chapters together act as a prelude for a call to action, with directions and initiatives set out for guidance. Chapter 7 examines contemporary issues in housing and the climate emergency—technologies of high performing housing, the tiny house movement, shared housing, neighbourhood-scale housing, circular housing, and innovative fnancing. Te prospects for their growth and development are examined in the frame of socio-technical transitions.

In sum, this book is richly referenced, well-informed, replete with case studies, and arranged as an accessible, reasoned call for carbon inequality and provision to be urgently addressed in our housing systems. Te vantage point is the edge of the fossil fuel era precipice, overlooking decades of Nero fddling while Rome is enveloped in the fames of market-based housing systems.

Melbourne, VIC, Australia Ralph Horne 3rd March 2023

# **Acknowledgements**

Many of the ideas we have explored in this book have been shaped and informed by a lifetime of curiosity around sustainability and the way the world works. However, we largely draw upon the research we have undertaken and discussions with our colleagues over the past decade.

As such, we wish to acknowledge that this book would not have been possible without the support of our current (and in the case of Andréanne—past) place of employment and organizations who have funded our research. In particular, we have had the opportunity to work with some amazing colleagues and we are thankful for their support and the contributions they have made to our research journeys to date.

We are also indebted to Emeralde O'Donnell as our copy editor who not only improved the clarity of our writing, but also challenged us to refne and elevate the key messages of the book. We are also thankful to Palgrave Macmillan for this opportunity and support to publish such a book, and for their patience through various delays in completing the book.

Finally, we are grateful to our families for their support, not only during the writing of this book, but more generally across the various challenges that academic life presents.

# **Expert Quotes on Book**

"*A transition to sustainable housing: Progress and prospects for a low carbon housing future* is a powerful call to action for a global transition to sustainable housing. Te authors skilfully lead readers through the current landscape of housing systems, policy, and research, providing the theoretical and empirical guidance—deftly illustrated by a variety of exemplars and precedent studies—to pursue sustainable housing. Te book provides beautiful explanations of complex systems and concepts, accessible to anyone approaching the topic for the frst time, while also being a brilliant, comprehensive resource for seasoned researchers."

—Dr Lyrian Daniel, *Associate Professor in Architecture University of South Australia; Deputy Director University of South Australia AHURI Research Centre*

"Trivess and Andréanne provide a much needed stocktake of current progress in the transition to sustainable housing. In addition to providing valuable insights on new approaches to buildings and technologies, they also remind us that it's not only about the hightech boxes we live in, but also where we live and how we live. Tey do not shy away from drawing attention to the limitations of allowing the market to lead housing and construction and they caution against new approaches that could deepen inequalities. Tey conclude with some insightful recommendations, of which we should all take note."

> —Dr Graeme Sherrif, *Reader, University of Salford; Chair, Fuel Poverty Research Network*

# **Contents**



$$\mathbf{x}$$




#### **Index** 279

# **About the Authors**

**Trivess Moore** is a Senior Lecturer in the Sustainable Building Innovation Lab (SBiLab) in the School of Property, Construction and Project Management at RMIT University in Australia. His research relates to housing quality and performance and focuses on the intersection between technical performance, liveability, social impact, and policy. Trivess is also a Trustee of the Fuel Poverty Research Network. Further information about his work and previous publications can be found here: https://bit.ly/3gZ3pAL

**Andréanne Doyon** is an Assistant Professor and Director of the Planning Program in the School of Resource and Environment Management at Simon Fraser University in Canada. Her current research focuses on urban governance and planning for resilient and climate just cities, sustainable housing, and questions of justice in sustainability transitions. Trough her work, she is interested in advancing new approaches and narratives around sustainability. Andréanne is also a Registered Professional Planner and a Member of the Canadian Institute of Planners. Further information about her work and previous publications can be found here: https://bit.ly/3B105Mj

# **List of Figures**


# **List of Tables**


# **1**

# **Housing for a Sustainable Future**

## **1.1 Introduction**

As a global society, we fnd ourselves at a critical juncture: after decades of fragmented and limited action, we are experiencing a climate emergency [1]. In the face of this crisis, our global and individual responses will shape the future, not only for the current generation but also for generations to come. Te built environment, which includes the housing sector, is a signifcant contributor of greenhouse gas emissions and wider environmental impact [2–4]. Globally, the housing sector contributes around 17% of total greenhouse gas emissions and consumes around 19% of total energy demand [2, 3]. Additionally, the housing sector consumes 30–50% of raw and recycled materials for building new housing and retroftting existing housing [4]. Te impact from materials occurs through the use of materials and the generation of waste during construction, through-life (maintenance), and at end of life.

Any transition to a low carbon future must include the housing sector and prioritize provision of sustainable housing [1, 5, 6]. Te transition should also acknowledge the disparate outcomes at play for housing with

#### **2 T. Moore and A. Doyon**

some jurisdictions1 over consuming energy, water, and materials and other jurisdictions struggling even to provide enough basic housing. Furthermore, sustainable housing is about more than reducing environmental impacts; it has a range of benefts including improving occupant health and well-being and reducing living costs at the individual dwelling scale and reducing the need for energy infrastructure at an urban scale [5, 7–9]. Given there are increasing numbers of sustainable houses and communities around the world, we know that we have the technology and knowledge to make sustainable housing possible.

In this book, we use the term housing to mean any type of building or unit that provides shelter or lodging for one or more people. Housing provides people with a place to sleep, eat, relax, be safe, and conduct their daily lives. Troughout the book, we discuss diferent types of housing, such as detached, semi-detached, and apartments, as sustainable housing is relevant for all housing types. We defne sustainable housing as housing with a zero carbon impact that, where possible, contributes to regeneration initiatives that support wider sustainability. Sustainable housing is housing that signifcantly reduces its life cycle impacts and engages with concepts of the circular economy (e.g., design for disassembly). Our focus on zero and low carbon performance outcomes aligns with the wider international research that argues for signifcant greenhouse gas emission reductions of 80% or more from key sectors [1, 3]. We use the term low carbon throughout the book to refect signifcant performance improvements of sustainable housing compared to a business-as-usual approach. However, it is more than just physical elements or specifc technical outcomes; sustainable housing improves health and well-being, reduces living costs, and connects to other sectors such as transport, food, and energy networks. Sustainable housing draws on a variety of design, material, technology, and construction innovations to build housing that will perform well now and into the future. Tis is not just performance from a technical perspective but also in terms of resiliency against a changing climate (e.g., resilient to extreme weather events).

<sup>1</sup> In this book we use the term 'jurisdiction' to refer to a country, region, or territory over which an authority (e.g., government) can make and enforce policy. While jurisdiction will often be a single country (e.g., Australia), it also refers to a larger collective of countries in some instances (e.g., the European Union).

Tis book examines the role sustainable housing must play in the transition to a low carbon future. We begin by identifying where we are currently situated in the sustainable housing transition and then explore the opportunities for moving forward, both as individuals, and as a global housing society. Tere is a signifcant amount of research on sustainable housing, but much of it is focused on small parts of the wider picture (i.e., single developments or sector-specifc data). In this book, we aim to bring together a more holistic picture of sustainable housing and encourage readers to think beyond traditional considerations of housing. Te book focuses largely on developed countries due to the similarity of environmental overconsumption of resources, government intervention, and industry scale in the housing sectors, as well as wider social and fnancial housing issues prevalent throughout these countries. However, we do acknowledge diferent challenges that developing countries face with their housing and include examples from a variety of contexts. Te opportunities for a transition to sustainable housing are relevant for all. While written by academics, we hope that this book is accessible to a wide audience, from researchers, to policy makers, to those in the housing industry, and to households themselves.

Tis chapter begins by exploring the changing world we face, largely from a changing climate, and what that means for the built environment (Sect. 1.2). We then discuss why housing is important (Sect. 1.3) and what benefts and opportunities sustainable housing can provide (Sect. 1.4). In Sect. 1.5, we refect on why, given the benefts of sustainable housing, we fnd ourselves facing ongoing challenges with changing the housing industry around the world. We conclude the chapter (Sect. 1.6) with an overview of each chapter in the book.

#### **1.2 A Changing World**

Human activities are creating a climate crisis which will worsen without signifcant and urgent changes to the way we live as individuals and as a global society [1]. Te Intergovernmental Panel on Climate Change (IPCC),2 continues to warn that time is running out as we speed towards irreversible outcomes triggered by changes to our natural environment [1, 10–12]. Average global surface temperatures between 2011 and 2020 were found to be 1.09 °C warmer than temperatures between 1850 and 1900, and we are seeing an increase in frequency and severity of natural disasters and weather events (e.g., fres, foods, storms) [1].

Te impacts of a changing climate are wide ranging and will likely impact every aspect of our lives. Of increasing concern is not just the damage being done to the natural environment, but the social and fnancial implications this will have on us as individuals and as a global society, particularly because those most vulnerable in our communities face unequal impacts [13]. Tis includes the impact on our children and future generations who will bear the brunt of any impacts despite not contributing to the decisions that created the climate crisis. A report released by Save the Children International3 found that, even under proposed environmental protection and carbon emission plans as set out within the Paris Agreement from 2015 [14], a person born in 2020 compared to a person born in 1960 would experience on average [15]:


Despite the climate emergency being the most signifcant environmental, social, and fnancial challenge of our time, governments, companies, and individuals around the world continue to hesitate on taking the urgent action required to transition to a low carbon future. Most climate and environment scientists have stated that we will need to reduce our global carbon emissions by 80% or more by 2050 to avoid catastrophic climate change [1]. While we have the technology and knowledge

<sup>2</sup>Te IPCC is the world's peak body on climate change.

<sup>3</sup> Save the Children International is an aid and development agency dedicated to helping children around the world. It is an independent and not-for-proft organization with 30 national members.

available to move towards and achieve this outcome, governments and other key stakeholders continue to delay making the necessary decisions to do so. Te limited outcomes from the 26th United Nation Climate Change Conference of the Parties in Glasgow in November 2021, and the 27th United Nation Climate Change Conference of the Parties in Sharm El-Sheikh in November 2022, demonstrate the inability to deliver a global consensus on a way forward. Te lack of consensus also demonstrates that there are still powerful, vested interests involved in key decision making with many embedded stakeholders from the current regime4 (e.g., fossil fuel industry) having undue infuence.

While addressing climate change and greenhouse gas emissions has been a signifcant focus of many researchers and policy makers, our need for improved sustainability goes beyond just reducing greenhouse gas emissions. We are increasingly consuming goods and materials at faster rates than the world can replenish. Due to both an increasing population and increasing consumption from this larger population, World Overshoot Day5 is occurring earlier each year. In 1972 the overshoot day occurred on December 25; 50 years later, in 2022, it occurred July 28 [17]. However, this impact is not equal around the word. In 2022, Qatar (10th February), USA and Canada (13th March), Australia (23rd March), and Denmark (28th March) were among the earliest overshoot dates, whereas Indonesia (3rd December), Jamaica (20th December), and South Sudan (25th December) were among the latest. As a global society, we are currently consuming at the rate of 1.75 planets per year, highlighting the challenge we face not only in reducing greenhouse gas emissions but also in living within the means of our planet [17].

Without a strong global agreement to address climate change and other sustainability challenges, there are increasing numbers of individuals, companies, and jurisdictions pursuing actions to move towards what is required for a low carbon future. However, more must be done across the globe to ensure this is a fair, equitable, and efcient transition, and that it does not leave those who are most vulnerable behind.

<sup>4</sup>A regime is defned as the articulation of the paradigm sum of current practices, beliefs, methods, technologies, behaviours, routines and rules for societal functions [16].

<sup>5</sup>World Overshoot Day is a measure of what day we exceed the earths biocapacity.

It is critical that any plans for a low carbon future incorporate the built environment (including our buildings, infrastructure, transport, and cities) [18, 19]. Tis is not just about what we add to the built environment (e.g., new buildings, roads), but also about what already exists. Sustainability retrofts of our existing built environment will be critical for a low carbon future [20–23].

Te need to better consider the design, quality, and performance of our built environment is not a new concept [24]. For example, ideas around sustainable development were popularized in the Our Common Future report [25], which defned sustainable development as 'development that meets the needs of the present without compromizing the ability of future generations to meet their own needs' (also known as the Brundtland defnition). Tis defnition considers both limited resources and intra- and inter-generational equity. Tis defnition of sustainable development also tries to balance the potentially competing pillars of the environment, society, and economy. However, this type of development has been difcult in practice within a neo-classical capitalist market that prioritizes fnancial growth over environmental and social outcomes. Outcomes of sustainable development have not yet matched what is required for a low carbon future.

While the Brundtland defnition of sustainable development has been useful for guiding discussion and actions towards sustainability, we argue, as others have over recent decades, that this defnition is no longer ft for purpose and will not help us achieve the type of low carbon future we urgently need. When considering that the global population of more than 8 billion (2023) is expected to increase to almost 10 billion by the middle of the century, that natural resources are rapidly decreasing, there is growing disparity of inequity, and that there is the urgency of the climate crisis, it is clear that sustainable development as previously defned and applied is falling short of current and future needs.

Sustainability needs to go beyond the idea of 'sustaining' or limiting environmental impact. Given the current context, sustainability must be regenerative, where we actively work to undo much of the damage we have already created. One simple way to think about this is to look at a tree: a tree provides fresh air, nutrition, habitat, and shade, among other attributes, but it also needs soil, water, and other nutrients to survive and grow. A low carbon future is not only a future that produces signifcantly less carbon, but also a future in balance with the world's resources so we can achieve a one planet outcome.

In addition to declaring the climate emergency, there have been several other critical global policy developments in recent years. Tese policies aim to address both environmental and social-equity issues which have been exacerbated in recent decades as the gap between jurisdictions and individuals with and without wealth continues to grow. Chief among these is the United Nations Sustainable Development Goals (SDGs). In 2015 the United Nations General Assembly adopted the 2030 Agenda for Sustainable Development which included 17 SDGs covering a range of issues facing vulnerable populations [26]:


While many of these have some overlap with the built environment, key SDGs for the housing sector include Goals 7, 11 and 12. Many jurisdictions and companies have adopted these goals and are aiming to achieve outcomes by 2030.

What is clear is that a transition to a low carbon future must be about more than environmental outcomes. We must use this opportunity to re-orient our global society to improve social and fnancial outcomes and close, or even eliminate, the gap in inequities that have continued to grow as the sustainability transition starts.

## **1.3 The Importance of Housing**

Housing is imperative to meet our basic human needs. It plays an important role in providing households with a safe, secure place to live, and it creates opportunities for enhancing social capital outcomes like health and well-being. Te importance of housing and the right to adequate housing is enshrined in the United Nations 1948 Universal Declaration of Human Rights. Te United Nations states that [27, pp. 3–4]:

*Adequate housing must provide more than four walls and a roof. A number of conditions must be met before particular forms of shelter can be considered to constitute "adequate housing." Tese elements are just as fundamental as the basic supply and availability of housing. For housing to be adequate, it must, at a minimum, meet the following criteria:*


Despite housing being a human right, there remain ongoing global issues with the delivery of 'adequate' housing as defned by the United Nations, and housing remains precarious for a large percentage of the global population. For example, the absence of adequate housing has negative consequences for both the overall rates of poverty and the ability to move out of poverty. Te United Nations and others report that the number of people living in extreme poverty (living on less than US\$1.90 per day) declined from almost 2 billion (or just over 35% of the global population) to 645 million (7.1% of the global population) between 1990 and 2019 [28]. However, this number increased to 738 million (9.5% of the global population) in 2020, the frst year of the COVID-19 pandemic, and was predicted to increase as the impact of the pandemic unfolded [28–30]. While the number of people living in extreme poverty has declined over recent decades (notwithstanding the impact of COVID-19), it is estimated that 3.3 billion people around the world still live below the poverty line of US\$5.50 per day [30]. It is also reported that climate change is predicted to push more than 100 million additional people into poverty by 2030 [30].

Tere is a signifcant overlap between people in poverty and their housing situation. Globally, there were more than 1.03 billion people living in slums or informal settlements in 2018 [31]. Te dwellings in these settlements typically do not meet the United Nations defnition of adequate housing. Furthermore, there are more than 100 million people without homes [32]. Such outcomes are not limited to developing countries. For example, in Australia, around 3.24 million people (13.6% of the population) are living below the poverty line of 50% of the median income (AU\$457 per week for a single adult), including 774,000 children under the age of 15 [33]. In the USA, there were 37.2 million people in poverty (11.4% of the total population) in 2020, which had increased by more than 3.3 million from 2019 [34].

It is not just the provision of housing that has impacts for households, but also the design, quality and performance of the dwelling. For example, a growing body of evidence demonstrates relationships between housing design, quality, and performance and the impacts on the social and economic well-being of households [7, 35–43]. Good dwelling design, quality, and performance can elevate a range of social benefts, while poor design, quality, and performance can lead to signifcant negative outcomes for households. Tis is not just an issue in developing countries but also in developed countries. For example, in New Zealand [44] it was found that:


Tese negative outcomes are not just problematic for the individual household, but also have implications for policy makers and the wider community. For example, the cost of people living in the bottom 15% of United Kingdom (UK) housing costs the National Health Service £1.4 billion per year [45]. In many cases, vulnerable households have housing impacts exacerbated by a legacy of poor quality housing [46]. Furthermore, housing contributes to the accumulation of larger scale issues such as air quality. Te United Nation reported that in 2016, 90% of urban residents were breathing polluted air that failed to meet World Health Organisation air quality guidelines [31]. Low- and middle-income countries are more severely impacted.

Te design, quality, and performance of housing also impact how afordable a dwelling is to live in. Housing afordability is increasingly becoming a global issue. In many jurisdictions, the cost of both purchasing and renting a home has increased rapidly in recent years, an increase that is faster than the increase in wages. Te wider housing research and policy community defne housing afordability using the 30% threshold where housing is considered unafordable when a household is spending more than 30% of their income on a mortgage or rent. Globally, there in an increasing percentage of households struggling with housing afordability and in many cities low to middle-income households can no longer aford to buy dwellings [47–50]. However, the traditional way of thinking about housing afordability as capital costs is likely masking a range of other housing and fnancial challenges, such as the cost of maintenance and daily living. Te design, quality, and performance of a dwelling infuence how much energy and other resources are required. Poor design, quality, and performing housing uses signifcantly more energy, water, and other resources compared to sustainable housing (see Sect. 1.4).

Te cost of energy, for example, has rapidly increased in many locations making housing costs increasingly unafordable. Tis has resulted in a growing number of households being in or near fuel (or energy) poverty [43, 51–58]. Fuel poverty is where a household cannot aford to pay for energy to meet basic living requirements (such as maintaining thermal comfort within a health range) or where the household self-rations energy consumption or makes other trade-ofs to ensure energy bills can be met [55, 59]. Tis is not just an issue confned to developing countries or housing slums, but is a growing issue in jurisdictions like Australia, Europe, and the UK. Fuel poverty is not only about the economics of paying for energy consumption, but if a household is not able to consume sufcient energy to meet their basic needs such as heating and cooling, it has implications on their health and well-being. Research has found that renters and low-income households are predisposed to experiencing issues of fuel poverty, but it is an issue increasingly impacting other socio-economic groups [57, 58, 60].

Not only do we need to address the critical social issues touched on above, we need to do so within the context of a growing population. How and where to house people is a pressing issue for policy makers, planners, and wider communities. It is not just a matter of providing more housing, but making sure we do so in a way that is equitable, just, and ethical [61, 62]. Te promise of sustainable housing not only addresses the climate emergency and resources used for construction, it also addresses wider social and fnancial issues.

#### **1.4 The Promise of Sustainable Housing**

Te good news is that the housing sector is considered 'a low hanging fruit', which has the potential to improve environmental, social, and fnancial outcomes signifcantly for little, if any, additional costs. Tis is why the housing sector has been identifed as a key sector within a range of local, national, and international strategies to move towards a low carbon future [3, 63–68]. Tere is an increasing number of examples from around the world that demonstrate the critical role that sustainable housing will play in an equitable and low carbon future. Tis will be discussed further in Sect. 1.5 and case studies can be found in Chaps. 6 and 7.

Tese real-world case studies, and an emerging body of research, demonstrate there are signifcant benefts for households, the wider community, the construction industry, and policy makers that can be delivered through signifcantly improving the design, quality, and performance, and sustainability of our new and existing dwellings. Such benefts include reducing environmental impact (during the construction, occupation, and end of life phases), reducing costs of living, improving occupant health and well-being, improving household and community resilience, creating a more stable energy network, and mitigating some of the social issues noted earlier [8, 47, 69–71].

For example, researchers have found that poor design, quality, and performance of a dwelling can signifcantly reduce occupants' liveability, health, and well-being, and that improved design, quality, and performance can signifcantly enhance it [5, 8, 42, 43, 45, 60, 69, 70, 72–83]. Health benefts from improved design, quality, and performance include a reduction in respiratory disease, improved sleep, and a reduction of the severity of issues like arthritis, colds, coughs, and other milder ailments [7, 8, 37–39, 70, 72, 81]. Tose who are most vulnerable, such as children, the elderly, or those who are low income, are often disproportionately impacted by negative health outcomes from housing. However, these groups also gain the most from signifcant design, quality, and performance improvements. Research from Boston (USA) found that a cohort of public housing tenants in sustainable housing experienced a reduction of 57% in self-reported health issues compared to standard public housing [84]. As noted earlier, this links to wider community costs and benefts, such as the cost implications for the health care system [45].

Improvements to the design, quality, and performance of a dwelling also results in reducing the need and usage of mechanical heating and cooling [9, 85]. Tere are some sustainable houses in certain climate zones that can provide year-round thermal comfort with no mechanical heating and cooling. A reduction in heating and cooling requirements has multiple benefts, including reducing energy consumption and therefore operating costs. Tis helps improve afordability outcomes for households. In an increasing number of examples, the reduction of energy requirements for heating and cooling, combined with other design and sustainable technology inclusions (e.g., renewable energy), has eliminated day-to-day bills related to energy and water costs. Te 'smart' homes innovation is promising to elevate these benefts of more energy and water efcient homes. Integrating technologies and appliances places the household at the centre of a dynamic two-way interaction with the wider urban and energy environment and maximizes environmental, fnancial, and social outcomes [86–88].

By reducing living costs, sustainable housing can save households hundreds, if not thousands, of dollars each year. Research in Australia, for example, found that households in a high performing zero energy dwelling could save more than AUD\$90,000 in energy bills over the assumed 40-year life of that dwelling [6]. Tis potential economic saving is likely to be even greater with the price of energy increasing more rapidly than previously predicted. Te economic benefts do not just stop there. If owners re-invested energy savings into their mortgage payments, they could ofset any additional capital costs associated with sustainable design which would reduce the interest paid on the home loan by more than AUD\$50,000 across the loan's life and result in paying of the house up to four years sooner. Research from the UK found that households in energy efcient housing were less likely to be in mortgage payment arrears than those in energy inefcient housing [89].

Tese types of benefts are also available when undertaking a largescale sustainability retroft of existing housing. Even small retrofts such as draught sealing, installing ceiling fans, and other internal changes can reduce the requirement for mechanical heating and cooling and signifcantly reduce energy costs for households [21, 90, 91].

Sustainable housing also adds fnancial value at the point of sale or lease. Research from around the world fnds that improving design quality and performance can result in an added sale value of 15% (or more) [7, 9, 92–97]. Some research has found that the added resale value from sustainable design and technology elements is greater than the cost of investment, such as with the case of heat pumps in the United States of America (USA), which were found to have an installation cost of around US\$8000 but result in an added resale value of US\$10,000–\$17,000 [97]. In addition, research has found that houses with improved design, quality, and performance were on the market for less time [98]. Tere are also fnancial benefts when a sustainable dwelling is part of a wider sustainability focus. For example, access to local amenities such as parks or having a view can add a further 15% (or more) to resale value [99–103]. Recent research from Sydney, Australia, even found that an increase of tree canopy on the street could increase sale values of property by AUD\$33,000–\$61,000 [104].

Te importance of what is around the outside of a dwelling is key for any discussion, not only for how to deliver sustainable housing, but also as part of a wider urban push towards improved sustainability. For example, increasing tree coverage and other natural features around dwellings can signifcantly reduce heat island impact (where excess heat is trapped within the built environment). An urban area with high coverage of trees or nature can reduce ambient air temperatures during extreme weather days by 15 °C or more [105–108]. A reduction in wider air temperature will keep dwellings cooler which reduces the need to use air conditioning and the associated costs for energy consumption. Tis can then have wider fnancial, social, and environmental benefts for the energy network by reducing the need to provide energy in peak weather events (which can be costly) and reducing issues such as energy blackouts due to high demand. It also impacts on peoples well-being. Research from Canada's heat dome event in 2021 found there was an increase of community deaths by 440% due to the extreme conditions and that those who died had lower greenness within 100 m of their dwellings [109].

Te good news is that an increasing amount of research and real-world examples of sustainable housing have demonstrated that it is possible to signifcantly improve the design, quality, and performance outcomes of new and existing housing within our current building practices and existing design, materials, technologies, and construction techniques (see Chaps. 6 and 7 for case studies). Notable case studies which have emerged over recent decades include the Vales Autonomous house and BedZED in the UK, Circle House in Denmark, Nightingale Housing, Lochiel Park and Cape Paterson ecovillage in Australia, and zHome in the USA [110–116].

Many of these examples, and those presented in later chapters, show that sustainable housing has a range of benefts beyond just improving environmental outcomes and it has the capacity to address a number of the wider social equity and justice concerns touched on earlier in the chapter [8, 47, 57, 70, 117]. However, delivering these sustainable and ethical outcomes is currently easier said than done. Barrett et al. [61, p. 3] state that 'ethically oriented cities will ultimately be the ones that succeed in enhancing resilience, improving quality of life, creating productive economics and reducing the environmental burden for all residents'.

#### **1.5 The Current System**

While the benefts of sustainable housing are clear within a research context, there is only a small percentage of the housing market that currently achieves design, quality, and performance outcomes in line with what is required for a low carbon future. Te low uptake, despite the benefts such housing provides, points to market failures [118]. With a 'perfect' neo-classical market, the belief is that if housing consumers or the housing construction industry sees value in improving the design, quality, and performance of the housing stock, consumers or building stakeholders will drive such improvements [6]. However, this is not occurring. For example, more than 80% of new dwellings in Australia are built to only meet minimum standards and only 1.3% of all new housing in the UK was built to the Energy Performance Certifcate rating 'A' between 2020 and 2021 [19, 119]. Tis wider market structure has been challenged within the environmental economics and broader social and sustainability literature [1, 3, 6, 9, 19, 62].

Due to these market failures, governments have introduced, and then periodically revised, minimum design, quality, and performance requirements for new and existing dwellings. Te housing construction industry is often resistant to the introduction or improvement of these regulations, claiming that such requirements create 'red tape' that adds time and costs to construction or renovations which is then passed onto consumers and further adds to afordability issues [6, 120]. Tey also often state that they are delivering the type of design, quality, and performance of housing that consumers want.

Te introduction of minimum building design, quality, and performance requirements by many jurisdictions over recent decades has been shown to be efective at lifting the bottom of the market and improving sustainability outcomes [65]. A range of studies has found that building energy codes have improved energy performance in housing by up to 20% (or more) [121, 122]. Despite the argued lack of progress towards the type of sustainable housing we will need to ensure a low carbon future, there has been a surprisingly long policy history in some jurisdictions with minimum performance requirements introduced into building codes as early as the 1940s [123, 124]. In many cases, these minimum requirements do not yet require outcomes that align with a low carbon future or with our earlier defnitions of sustainable housing [125, 126]. Tere are a small, but increasing, number of jurisdictions who have made more signifcant progress in this space (e.g., California, the European Union), as will be discussed in more detail in Chap. 2.

Tere is also a range of other policy mechanisms which have been implemented in diferent jurisdictions in recent years. Of note is the mandatory disclosure policies that require dwelling owners to provide the energy or sustainability information of their property to be provided at point of sale or lease [127]. Te intent of such a policy is to provide potential purchasers or renters with more information about their housing choice, and an incentive for the current owner to consider and undertake retroft activities that would improve the rating and (ideally) realize increased fnancial value.

Additionally, planning schemes in many jurisdictions have also been important for driving sustainable housing outcomes, either when minimum building code requirements fall short or as complementary measures to help deliver enhanced outcomes [128–131]. For example, design guidelines at the dwelling or neighbourhood level and other mechanisms such as creating 'zones' have been used to some success in various jurisdictions.

Despite these approaches, there is an urgent need to do more to transition to a low carbon future. Tis book unpacks many of the ideas touched on in this chapter and explores them in more detail with a key focus on how we can equitably scale up the delivery of sustainable housing as part of that low carbon transition.

#### **1.6 Overview of the Book**

Clearly, as a society, we fnd ourselves at a critical juncture in relation to many critical environmental, social, and fnancial issues. How we address these issues over the coming decades will determine what type of future we create and what type of world we leave for future generations. Tis book starts from the position that we must urgently transform our housing to become more sustainable, not only from an environmental perspective but also to enhance social and fnancial outcomes for households. If we delay in making the changes necessary, we will be locking in substandard housing and impacts on households for decades to come.

A transition to low carbon housing is going to require more than just incremental change to housing design, quality, and performance. Tis book aims to challenge policy makers, planners, housing construction industry stakeholders and housing and urban researchers to rethink what housing is, how we design and construct our housing, and how we can better integrate impacts on households to wider social policy development.

In Chap. 2 we explore how we are broadly providing housing currently around the world and look at how multiple market failures have resulted in housing design, quality, and sustainability being undervalued by policy makers, the housing construction industry and housing consumers. We discuss how building codes, planning systems, and a range of alternative mechanisms have attempted to address these market failures.

Chapter 3 further explores a number of the key points raised in Chap. 1 and focuses on why we are at a critical juncture where we need to make urgent changes if we are to provide sustainable housing to help achieve that low carbon future. We explore how this is not just about addressing environmental issues but also an opportunity to address a range of other social justice and equity issues which have been exacerbated by rapidly spiralling housing unafordability and design, quality, and performance issues around the world.

Following this, Chap. 4 presents the sustainable housing challenge and presents a number current and future challenges preventing a sustainable housing transition. We look at these changes across a number of diferent scales include the dwelling scale, neighbourhood and city scale and the state, national and international scale and discuss what these mean in the context of a sustainable housing transition.

In Chap. 5 we present an overview of sustainability transitions theory as a framework which could help us facilitate a transition to a sustainable housing future. We explore the theory including recent sustainable housing transitions research. In doing this, we identify a number of sociotechnical dimensions which we argue are important for addressing if we are to create deep structural changes to enable a wider sustainable housing transition.

Tese socio-technical dimensions are then discussed in detail in Chap. 6 where we defne the dimensions and explore the contrast of how they are addressed by the current housing regime and sustainable housing niche. We provide short examples to demonstrate how these dimensions are being addressed in practice.

Building upon this, Chap. 7 presents six key sustainable housing themes: high performing housing, small housing, shared housing, neighbourhood-scale housing, circular housing, and innovative fnancing for housing. We highlight how these themes are challenging the existing regime and discuss how the theme and specifc case studies are demonstrating the socio-technical dimensions.

We then refect in Chap. 8 upon these case studies, and the key discussions and evidence from the earlier chapters of this book, to discuss the sustainable housing transition including where we are placed in that transition, potential pathways forward and challenges that still need to be addressed. We then refect on the types of innovation across policy, practice, and research required to help facilitate the sustainable housing transition.

In Chap. 9, the fnal chapter of the book, we go back and revisit the core ideas woven throughout and summarize the current situation we fnd ourselves in relation to the provision of housing which is not going to meet our environmental or societal needs moving forward. We discuss the prospects for change and explore where that change needs to occur. We fnish the chapter with some concluding refections.

#### **References**


**Open Access** Tis chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence and indicate if changes were made.

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# **2**

# **Current Housing Provision**

# **2.1 Introduction**

In Chap. 1, we explored the climate emergency and the role the housing sector plays as a signifcant contributor to greenhouse gas emissions and other environmental impacts (e.g., material consumption). We also talked about the importance of sustainable housing for environmental, social, and fnancial benefts it can provide. Te evidence is clear that sustainability can improve several critical issues facing the housing sector, households, and policy makers. We also presented an overview of the current system of housing provision, discussing that addressing deeper structural issues within this system is important if we are to transition globally to a low carbon future.

In this chapter, we explore current housing provision in more detail and outline how we have arrived at the current way of 'doing' housing, including the governing, fnancing, planning, designing, building, and habitation of housing. We start the chapter by discussing the market failures of housing and neo-classical market approaches that are not suitable for providing the type of sustainable housing required for achieving a low carbon future (Sect. 2.2). To address this, the use of policy by various levels of government has been a critical driver of housing design, quality, and performance. However, many sustainability advocates argue that these policies have been slow to improve and do not go far enough, given the current climate emergency and other housing issues seen around the world. We discuss some of these key policy mechanisms, including setting and improving minimum performance requirements in building codes (Sect. 2.3), using planning systems to require additional sustainability standards (Sect. 2.4), and developing fnancial and other alternative mechanisms (Sect. 2.5). Tis sets the context for later chapters where we explore the range of challenges facing the housing sector and discuss current best practice in sustainable housing and policy.

## **2.2 The Market Failure of Sustainable Housing**

Globally, the housing construction industry largely operates under a neoclassical economics framework—a framework which has guided societies and industries around the world for many decades [1–4]. Neo-classical economics theory states that competition in the market benefts both consumers and industry which ensures efciencies between supply, demand, scarcity, and cost [5–7]. Tereby, this competition reduces the requirement for government intervention as industry and consumers will determine what the best outcomes are including what products, materials, and services are valued and desired. Tis idea of 'competition' and the need to innovate to fnd cost efciencies has reinforced the narrative the housing construction industry uses to advocate for fewer (and certainly not more) regulations.

Opponents of regulations that set requirements for quality and sustainability (among other outcomes) claim that these regulations create 'red tape' which adds time and cost to developments which are passed onto consumers and create further fnancial challenges in an already unafordable housing market [8–11]. It is also argued that regulation does not only impact the bottom end of the housing market, but also stifes the ability of companies to innovate when the innovation does not conform to regulations. Terefore, in these arguments, consumers miss out on two fronts: it adds costs but also constrains what the industry can delivery.

Instead, opponents of regulation suggest that consumers will use the competition of the free market to decide what types of housing they want built, where they want it built, and at what quality and sustainability level. Tis means that if someone wants a large house, they can have a large house as long as they have the money. If they want granite benchtops in their kitchen, they can have them. And if they really want extra insulation, solar panels, double-glazed windows, and passive solar performance, they can have it. But consumers must ask for these things *and* be able to pay for them.

Tis thinking is based on three critical assumptions about consumers: (1) that consumers make rational decisions, (2) that consumers make decisions that maximize the outcome for themselves, and (3) that consumers make these decisions independently, based on complete information [2, 12]. Tese assumptions are contested within the environmental economics and broader social and sustainability literature [13–16].

We know that consumers often have other motivations distinct from self-interest and proft maximization, which are part of the choice process, or have a range of constraints impacting their decision making. Yet, these realities are not captured in the above assumptions and consumers rarely have complete information when making choices [17–21]. For example, the decision to buy a dwelling is limited to the existing dwellings available for purchase at that point in time or fnding land to build a new dwelling (or via knock-down rebuild), which itself is limited to what is available or already owned. Tis decision is also constrained by budget. Similar constraints apply for renters. In many countries, there is currently an undersupply of housing, making it even more competitive or challenging for those wanting to buy or rent property [22, 23]. All this means that housing consumers face a constrained choice, even before other factors like improved sustainability are considered and therefore the market is not operating as the theory about the free market suggests.

Tis neo-classical market framework has enabled signifcant wealth accumulation by key stakeholders in the housing construction industry at the expense of housing quality, afordability, sustainability, and social outcomes (see Chap. 3). It is not just key stakeholders in the housing construction industry who have made signifcant profts from construction, but also governments. Governments are heavily dependent on construction in many parts of the world. Te health of the housing construction industry is intrinsically linked to diferent levels of government, as it is a key determinant of economic measures like Growth Domestic Product and provides signifcant income for governments via development fees and property and land taxes. We have seen evidence of this with governments' responses around the world to the Global Financial Crisis in the late 2000's and COVID-19 recoveries (from 2020 onwards) where infrastructure and building projects have been key pillars of economic and social recovery. However, this can also be seen as a catch-22, where governments have found themselves wanting to make housing more afordable and accessible to all, but knowing that any decrease in housing value will impact their property income and the broader health of the economy. It is a tightrope that governments have been walking for decades and the loser is often the consumer; we are seeing the price of housing for purchase or rent rapidly increase in many jurisdictions around the world, often faster than the increase in wages and often without any measurable improvement in housing quality, sustainability, or even access to nearby amenities.

As explored in Chap. 1, sustainable housing has a clear range of benefts. In addition to providing more basic safety and security that housing entails, sustainable housing can reduce environmental impacts, reduce living costs, and improve health and well-being [24–26]. If we accept the 'rational' consumer assumed by the industry and many policy makers, we should expect to see consumers demanding improved sustainability outcomes for new and existing housing. However, around the world, we have seen that consumers are generally not engaging with sustainability beyond what is set in minimum performance standards unless there is signifcant fnancial incentive for them to do so (e.g., residential solar rebate programmes, mandatory disclosure of building performance programmes). For example, research of the Nationwide House Energy Rating Scheme in Australia found that from 2016–2018 almost 82% of new detached housing was built to meet only the minimum building code requirement, with only 1.5% built to the economic and environmental optimum (higher) performance [27]. From 2019 to July 2022, this had fallen to 1.4% of new housing [28] despite it corresponding to the period of time where signifcant public, industry, and policy discussion was occurring about a likely increase to minimum building performance requirements that were announced in August 2022.

Some jurisdictions are delivering a much higher percentage of new dwellings closer to the technical performance outcomes required for a low carbon future. For example, data from the UK found that, while there was only around 1.3% of all new housing built to the Energy Performance Certifcate rating A across 2020–2021, most new houses are achieving an Energy Performance Certifcate rating B (Fig. 2.1). While this might seem like a good outcome, especially in comparison to Australia, the design, quality, and performance of new housing in the UK is still being criticized for being insufcient to respond to the climate emergency [9]. Additionally, with new dwelling construction only representing a small percentage of the overall stock in the UK, the more signifcant issue is the poor design, quality, and performance of existing housing which primarily have ratings of D or worse (Fig. 2.2).

**Fig. 2.1** Energy Performance Certifcate ratings for new housing in the UK from 2012–2021. Energy effciency grades from A (best) to G (worst) [29]

**Fig. 2.2** Energy Performance Certifcate ratings for existing housing which undertook an Energy Performance certifcate in the UK from 2012–2021. Energy effciency grades from A (best) to G (worst) [30]

Te push by some key housing construction industry stakeholders and policy makers to leave housing quality and performance 'to the market' assumes that consumers can access and understand the design, quality, and performance information of dwellings. Tis has largely been found to not be the case, both in terms of access to such information as well as the understanding of what it means [21, 31].

Tere are some notable attempts to provide housing customers improved information about the design, quality, and performance of housing to address market information gaps [32]. For example, mandatory disclosure of building performance, which typically requires all houses being sold or rented to have an energy or performance rating, are among some of the longest running housing information programmes. Such programmes include the Energy Performance Certifcates across the European Union (EU) and UK and the Civil Law (Sale of Residential Property) Act 2003 in the Australian Capital Territory (Australia) [33, 34]. In some of these jurisdictions, there is now more than 20 years of data and research is increasingly focusing on understanding the infuence of the provision of information in these jurisdictions. Largely, the evidence suggests that the provision of easy to understand, verifable and independent information results in positive outcomes across a range of diferent metrics for housing consumers such as driving the uptake of energy efciency retroft.

Improved information for housing consumers is translating into an improved willingness to pay for sustainability in some jurisdictions. For example, housing consumers across diferent jurisdictions put a sale or rental premium of up to 15% or more on higher quality and performing dwellings [35–44]. However, positive sale or rent value is not universally found in the research. For example, in Northern Ireland, researchers found that dwellings with higher Energy Performance Certifcates were not more likely to increase in sales price [45]. In Chile, consumers associated higher ratings with higher prices which resulted in an unwillingness to pay for improved outcomes [46].

Beyond the impact on sale or rent price, improved information about dwelling quality and performance has been found to enhance opportunities for consumers to undertake retroft activities or seek out higher performing dwellings which would reduce their cost of living and improve other outcomes such as thermal comfort [47–50]. For example, Sweden is one jurisdiction with an early introduction of the EU Energy Performance Certifcate requirement where owners of multifamily dwellings were required to obtain a certifcate before the end of 2008. With the certifcates lasting ten years, there has been a signifcant number of dwellings in Sweden that have had a second rating completed. Von Platten et al. [51] analysed the frst and second round certifcations and found that energy performance in existing housing had improved and that improvement was greater in rental (private and social) rather than owneroccupied dwellings. In a study surveying homeowners across 12 EU countries, Charalambides et al. [50] found Energy Performance Certifcates played a role in renovation decisions as well as rent/buy decisions, but the results of the infuence varied signifcantly across jurisdictions. Te authors found that, for those who had already renovated their homes, 59% said the information played a very important role in undertaking the renovation and 20% said the information was somewhat important. Across the emerging body of research there seems to be a positive association with improving housing quality and performance and understanding the value of this.

Tere has also been research exploring the role language and key intermediaries, such as real estate agents and builders, play in educating consumers [52, 53]. Hurst [19] explored how the language used by real estate agents advertising houses for sale in Melbourne (Australia) engaged, or did not engage, with sustainability. Analysing more than 150,000 advertisements from 2008–2015, Hurst found that only around one in fve houses had some mention of sustainability. While this percentage slightly increased across the analysis period (up to one in four), Hurst was critical of the way sustainability terms were being used. Often, sustainability was used to elicit a feeling of 'home' rather than have more meaningful discussions. For example, 81% of the advertisements contained no key words about energy efciency and another 15% only contained one key word. Hurst [19] also found that, where sustainability was discussed, it was often placed in the middle of the text, while consumers are more likely to remember the frst and last parts they read. He argues that the lack of emphasis placed on energy efcient characteristics 'has the potential to dilute the importance of reducing energy consumption in housing and retard market acceptance'. (p 196).

It is not only real estate agents who have a critical role to play in disseminating sustainability information; the practices of the housing construction industry itself are just as critical [54]. Warren-Myers et al. [21] analysed the 30 largest builders of detached homes operating in Australia to see how they communicated on their websites about housing energy efciency and performance. Only two thirds of builders mentioned energy rating requirements, while half stated that the regulated 6 star minimum (0 worst–10 best) was part of their individual standard despite it being legally required. Furthermore, the researchers found that, in many cases, the builder's communicated information about the 6 star minimum in misleading ways. For example, there were multiple examples where websites presented a visual representation of stars, but with only 6 stars rather than 6 out of 10 (the maximum). Tis was deemed as misleading 'due to semantic confusion' and was arguably in breach of Australian consumer laws. In earlier research, it was noted that, 'the lack of information relating to sustainability provides evidence for why consumers demonstrate little engagement in the sustainability agenda when entering the building process' [52, p. 35].

Tis lack of consumer and stakeholder understanding about sustainable housing is not just limited to the dwelling itself, but also broader considerations of how the house is impacted by, and impacts, wider sustainability. For example, research by Ambrose [55] fnds that many people do not think about how the energy they use in their home is generated.

While these information programmes and intermediaries have been recognized as playing an important role in trying to improve understanding and engagement with sustainability in housing, there is an ongoing challenge that many consumers are not responding, or are unable to respond, to what improved performance of their housing means for them, society, or the environment. Consumers are responding to what is being provided or what they have known or experienced previously (i.e., social norms). Clearly, there continues to be a market failure occurring in relation to sustainable housing. Research that has asked what consumers look for in housing continues to identify elements such as price, location, number of bedrooms and bathrooms, and the quality of the kitchen above considerations of sustainability [19].

Tis market failure is not new. To address this issue, governments around the world have been trying diferent policy levers to improve the quality and performance of housing, including the aforementioned mandatory disclosure schemes. By far, the most common policy approach has been the setting of minimum performance requirements within building codes. Tere has been a long policy history in some jurisdictions with energy efciency and performance requirements in an attempt to improve the bottom of the market, while other jurisdictions have only engaged with this approach in more recent years [56]. Tis is explored in the following section.

#### **2.3 Building Codes**

Te frst building codes emerged in the 1940s and they were slowly introduced in many developed countries over the following decades. Tey are now a critical mechanism for addressing dwelling quality and performance [56–59]. Early iterations of building codes for housing were developed to address minimum levels of safety, quality, and performance for both the construction and occupation phases of the dwelling [60, 61].

Building codes are regulatory documents developed by governments, often in conjunction with peak housing construction industry stakeholders. Te codes outline what can, and cannot, be done in relation to design, materials, technology, and construction methods. Typically, building codes are either prescriptive or performance-based. Prescriptive regulations involve a detailed requirement for each element (e.g., staples shall be not less than 1.98 mm in diameter), whereas performance-based regulations provide more overall requirements (e.g., residential buildings shall be equipped with heating facilities capable of maintaining an indoor air temperature of 22 °C). In recent years, there has been a shift away from prescriptive codes to allow for fexibility and innovation and to account for complexities within buildings and across diferent building sites [59, 62].

In locations with mandatory building codes, someone who wants to build a new dwelling, or undertake signifcant renovation of an existing dwelling, would need to demonstrate compliance with the codes as part of any planning and construction approval process. Tis is typically demonstrated through a 'deemed to satisfy' approach (essentially, a box ticking exercise to ensure key requirements are met and that evidence can be provided to support those requirements) or through computer modelling to demonstrate that overall performance outcomes are met.

Figure 2.3 shows the overall modelling energy loads required for heating and cooling across diferent cities in Australia. Tis is set through the Nationwide House Energy Rating Scheme, which is a framework for evaluating the thermal performance of housing on a scale from 0 star (worst natural thermal performance) to 10 stars (best natural thermal performance, requiring virtually no mechanical heating and cooling) and links to the National Construction Code to demonstrate compliance with minimum performance requirements. Since 2010, the minimum performance requirement was to achieve a 6 star standard, which was improved to 7 star from 2023.

Te energy shortages of the 1970s were a key turning point for the consideration of energy and sustainability within building codes [56, 64]. Leveraging the wider focus on improving energy consumption and

**41**

**Fig. 2.3** The Australian Nationwide House Energy Rating Scheme star bands and energy load requirements [63]

efciency, building codes started to expand beyond safety elements to include minimum performance requirements for elements such as energy, heating, and cooling (thermal performance), lighting, water, and other sustainability considerations. Te use of regulation to improve sustainability in housing was, and still is, seen as a way to start to address broader market failures, ensure consistency, and reduce risks, uncertainties, and confusion over requirements [33, 65–68].

Te inclusion of energy and sustainability elements within building codes (sometimes referred to as building energy codes) are increasing, but are still not universal. Te International Energy Agency reported that, in 2020, there were 85 countries with mandatory or voluntary building codes that contained specifc energy requirements and another eight countries with codes in development. Tere were also a number of other jurisdictions (i.e., states or provinces) with building energy certifcations (either mandatory or voluntary) [59]. However, globally two in three countries lacked mandatory building codes with specifc requirements for energy, with many of these being in developing countries where some of the largest growth in residential buildings is occurring [59]. Where they have been implemented, mandatory building codes with energy and sustainability requirements have been found to be a critical mechanism for reducing energy consumption and greenhouse gas emissions from the housing sector. A range of studies has found that building energy codes have improved energy performance in housing by up to 20% (or more) [59, 69, 70].

Te introduction and development of building codes that address minimum performance requirements has happened sporadically and without international coordination. In most cases, each jurisdiction has developed its own requirements and this has resulted in signifcant variances in what is included, or excluded, from such codes. Tere have also been periods of more signifcant development (see examples below), but for the most part any revision of building code minimums has happened through subtle tweaks rather than signifcant steps forward. Tese requirements can also be quite challenging to change once set. In some locations like Australia, minimum performance requirements were changed in 2010 and were not signifcantly revised again until 2023, demonstrating how slow some jurisdictions have been to embrace or improve sustainable housing requirements.

While minimum dwelling design, quality, and performance requirements have been improving in many developed countries over recent decades, they remain short of what is required for a transition to a low carbon future and there are calls for further innovation that better aligns with the housing future we will require [31, 59, 67]. Some have also cautioned against the reliance on building codes as the only answer. For example, Cass and Shove [71, p. 1] argue that codes and standards are increasingly leading to outcomes that are 'disconnected from changing user needs'. Tey say that because the term 'standards' implies it is a good thing, it creates an industry norm and may result in stifing further innovation beyond the minimums.

Tere are, however, examples that have emerged over the past two decades which have aimed to go beyond the standard approaches to delivering housing performance.

#### **2.3.1 Mandatory Codes**

Collectively, the EU has developed a number of policies related to housing and energy efciency that guide Member States, including *Directive on the Energy Performance of Buildings* (2018/844/EU) (initially Directive *2002/91/EC*, but updated several times since its introduction) [72]. Te latest version of these policies sets regulatory requirements for Member States to ensure that all new buildings from 2021 (including residential) are nearly zero energy. Tere is also a signifcant focus on scaling up the delivery of cost-efective deep retrofts to existing buildings [72]. Tis regulatory approach is seen as a critical for the EU to achieve longer term greenhouse gas emission reduction targets, as well as a range of other outcomes such as improving energy resiliency and security. A review of the Directive's implementation found that, by the start of 2021, seven jurisdictions had performance requirements that were less energy demanding than the EU benchmarks, and only three jurisdictions had not implemented the requirement (Greece, Hungary, and Bulgaria); Greece and Hungary were noted as introducing the requirements by the end of 2022, while uncertainty over Bulgaria remains [73].

Te UK has been an early leader in the space of sustainable housing with the introduction of their Code for Sustainable Homes policy that set out a ten-year pathway to increase minimum sustainability requirements at set periods and to deliver zero carbon new housing by 2016. While the policy was withdrawn in 2015 when there was a change in government, the ten-year plan was seen as an important way to deliver certainty for the housing construction industry and other key stakeholders regarding how a transition to sustainable housing would be delivered [31, 74]. However, the withdrawal of the policy has lasting impacts for households. Since 2016, the removal of the Code for Sustainable Homes requirements resulted in more than £790 million of additional cumulative energy costs paid by owners of almost 1.2 million new homes [75].

In 2019, the UK Government announced a Future Homes and Buildings Standard that would result in new housing reducing emissions by around 80% when implemented by 2025 compared to performance of the 2013 building standards [76, 77]. In preparation for achieving this outcome, a step change improvement of performance of around 30% was introduced in 2022 [77]. In an analysis of sustainable housing policy development in the UK, Kivimaa and Martiskainen [78, p. 93] found that low carbon housing policy development improved the opportunity for transitions intermediaries to engage 'through increasing needs and resources to pilot, scale-up and implement policy'. Te introduction of these new short-medium term policy requirements in recent years is likely to further support opportunities for other stakeholders to innovate and be involved in the transition.

Te establishment of short-medium term policy pathways has also been applied in several other jurisdictions to guide a transition to sustainable housing. For example, in 2008, the state of California established a medium-term energy efciency policy plan to require new housing from 2020 be built to a nearly zero energy standard [79]. Since 2008, the plan has undergone several revisions. At the time of writing, the 2019 California Energy Efciency Action Plan is the latest version of the plan [80]. Te 2019 update seeks to double energy efciency by 2030, remove and reduce barriers to energy efciency in low income or disadvantaged communities, and reduce greenhouse gas emissions from the building sector. Specifc performance requirements for housing are established within the 2019 Building Energy Efciency Standards [80] which now include requirements for renewable energy technology and a range of other efcient technologies.

Tis approach, where a short-medium term policy plan is put forward, is becoming more common: several other jurisdictions have announced plans to transition to low carbon or energy buildings by 2030. Tis includes an announcement by the Canadian Federal Government in 2022 which stated a goal of net-zero energy ready buildings by 2030 [81]. Some jurisdictions within Canada have already started taking steps towards this outcome. For example, British Columbia enacted the BC Energy Step Code in 2017 to show the Province's commitment to taking incremental steps to increase energy efciency requirements for making buildings net-zero ready by 2030. Te BC Energy Step Code is a voluntary provincial standard, giving municipalities the option to implement the Energy Code and either require or encourage builders to meet one or more steps as an alternative to the BC Building Code's prescriptive requirements. Te code does not specify the construction of a building, but simply identifes energy efcient targets that must be met in a way that the design and construction team choose.

It is not always about achieving a zero energy or carbon goal. For example, Wales has set out their own requirements to reduce carbon emissions from new housing by 80% by 2025 [82]. Te requirements are not only about improved environmental performance and energy efciency but they are linked with broader social goals like improving occupant health and well-being and ensuring a resilient housing stock in the face of a changing climate. Te importance of integrating broader environmental or social goals into housing performance policy has been identifed elsewhere as being critical for strengthening housing performance outcomes in the face of a resistant housing construction industry [74].

#### **2.3.2 Voluntary Codes**

In addition to regulating minimum performances in building codes, there has been the emergence of voluntary energy rating tools which aim to help drive housing performance forward through systematic and robust frameworks. Tese voluntary tools have been developed for jurisdictions where regulations do not exist or where they are not sufcient to deliver the types of housing required for a low carbon future.

One prominent example is the Passive House standard, which originated in Germany but is now spreading internationally [83]. Passive House aims to deliver low energy, thermally comfortable, and afordable housing. Achieving a Passive House standard is up to 90% more energy efcient than typical housing [83]. Tis high performance outcome is achieved through strict requirements for thermal energy loads in the design, materials, technologies, and construction methods applied, as well as through rigorous compliance checking at multiple points throughout the construction process. It is the attention to detail during the build which is a key diference to many other sustainable housing approaches.

Another example is the Living Building Challenge standard which emerged in 2006 and aims to address several criteria including more traditional elements like energy, water, and materials as well as other criteria such as place, health and happiness, equity, and beauty. Unlike other standards, the Living Building Challenge aims to be a regenerative performance, requiring the building to do more than just meet net-zero. For example, the Living Building Challenge requires dwellings to meet 105% of their energy needs through renewable sources. It also goes beyond the technical focus of the building to include how the building adds value to the occupants and surroundings. Tese voluntary tools have had varying success but are increasing in popularity around the world, especially regarding shifting the focus to improving health and well-being for occupants.

## **2.4 Planning**

Te introduction of building codes and the shift from a focus on safety to minimum performance requirements (such as energy efciency) have resulted in improving housing design, quality, and performance. However, some researchers and policy makers argue that there has been an overreliance on building codes to deliver improved sustainability given the lack of compliance with them, tension they create with the building regime, and the often long lag times to amend to the codes [84, 85]. Over recent decades, this has led to attempts to infuence sustainability outcomes in the housing sector through planning systems in diferent parts of the world, at both the individual block development and larger urban scale.

Planning is concerned with shaping cities, towns, and regions by managing development, infrastructure, and services. Strategic land use planning (also known as physical planning or spatial planning) 'refers to planning with a spatial, or geographical, component, in which the general objective is to provide for a spatial structure of activities […] which in some way is better than the pattern existing without planning' [86, p. 3]. Statutory land use planning is also responsible for approving developments as all formal developments need permission from the government [87]. When it comes to the role of planning in housing, strategic planning is responsible for the location of housing; housing type, mix, and diversity; location of transport, jobs, and services; urban growth; and urban consolidation. Strategic planning takes a macro approach and creates area-wide policy plans that map general policy districts such as conservation, rural, or urban areas. It also creates communitywide land use design plans and is responsible for small-area plans such as transportation corridors, business districts, and neighbourhoods. Statutory planning is responsible for land use regulations, zoning, density, residential growth boundaries, and planning approvals and permits. Tere are several mechanisms employed by governments and urban planning departments to control land use. Tese include zoning, development controls, design guidelines, and building codes, among others.

Zoning is a system for developing various geographic areas that are restricted to certain uses and development. It is a tool for governments and urban planning departments to guide future developments and to protect areas and people. While the exact terms difer around the world, common zones include industrial, commercial (retail and ofce), agricultural, residential, mixed use, parks, and schools. Within each category of zones, each city will provide further defnitions and restrictions. For example, in the City of Vancouver, housing can occur in several diferent zoning districts such as multiple dwelling districts, two-family dwelling districts, one-family districts, as well as in other areas such as comprehensive development districts, historic area districts, and light industrial districts. In addition to zoning, other approaches include subdivision regulations, which are used to convert land for greenfeld suburban developments; tax and fee systems, including development contributions, which are employed to generate revenues needed to provide certain services or for infrastructure improvements; geographic restraints (growth boundaries) that control growth and limit development in specifc geographic areas; and ofcial mapping which provides the public with maps of proposed future facilities and their locations.

Architectural or urban design reviews are another method to control land use and the type and appearance of developments. Some jurisdictions have an urban design panel made of design professionals who advise the local government about development proposals or policies, including major development applications, rezoning applications, and other projects of public interest. Another instrument is design guidelines which are illustrated design rules and requirements that provide either prescriptions or strategies on the physical development of an area. Design guidelines have been successful in delivering a range of benefts, for instance, 'quality, certainty, coordination, land and property values' [88, p. 276]. Tese design guidelines go beyond the performance and design requirements found within building code requirements.

Planning operates within a multi-level governance context. In Canada, planning is a provincial matter but provinces defer their responsibilities to local governments. Provincial governments provide legislation and frameworks for how planning and associated activities must be carried out, as well as the structures for voluntary agreements with local governments. Whereas, in Australia, the state governments retain more control over planning with local governments responsible for implementing policies. In the USA, planning is mostly a local government exercise with literately thousands of diferent planning systems across the country. Tese governance contexts are even more complex with the addition of diferent systems such as building codes. For example, buildings codes fall under provincial/state jurisdiction in Canada and the USA, but national jurisdiction in Australia.

In diferent jurisdictions, the planning system has been used to intervene at the provincial/state and local level due to the limited ability to improve sustainability through the building code. In the state of Victoria (Australia), a number of local governments have had the *Local Planning Policy Clause 22.05 Environmentally Sustainable Design* incorporated into their planning scheme with approval from the state government. Tis clause allows local government to embed sustainability requirements into local planning policies. Most local governments have required planning applications be accompanied by a Built Environment Sustainability Scorecard which was designed to support the Sustainable Design Assessment in the Planning Process.

In British Columbia (Canada), the provincial government launched the B.C. Climate Action Charter in 2007; since then, the majority of local governments have signed on. Under the Charter, signatories commit to becoming carbon neutral in their cooperate operations; measuring and reporting their community's greenhouse gas emissions; and creating complete, compact, and more energy efcient communities. Local governments and planning departments use their Ofcial Community Plans (strategic planning document) and tools such as Development Permit Areas for Climate Action, which are designated areas for the purposes of supporting climate action through energy or water conservation and greenhouse gas emissions reductions, to ensure that planning decisions lead to more sustainable housing outcomes. Building examples include improved siting of building to capture solar energy, the provision of deep overhangs for shade, and the inclusion of rainwater collection systems or geothermal systems.

What can be seen from these examples is that the planning system in many jurisdictions can play a critical role in the provision of sustainable housing (new and existing), and where building codes fall short, planning requirements can push for improved outcomes. Te planning system is especially important for addressing sustainability beyond the individual dwelling level, which is typically not considered within building codes, or by individual dwelling owners. Given the challenge in transitioning to a low carbon future, improvements will need to come at diferent scales, which will be discussed further in Chap. 3.

#### **2.5 Alternative Mechanisms**

Further to the approaches explored above, there are a range of complementary approaches that have emerged in recent decades to address and guide improved housing design, quality, and performance. Tese approaches typically aim to address consumer barriers around market failures.

For example, there has been a range of attempts around the world to provide consumer education around how to reduce energy and water consumption and improve energy and water efciency within the housing sector [89]. Tese education campaigns, which are separate to the earlier discussion on mandatory disclosure of building performance, have provided basic energy and water literacy for how occupants infuence and improve housing performance through their everyday lives. Tere have also been education programmes focused on providing information around key design, material, technology, and construction method considerations that can create a more sustainable home. Tese programmes recognize that, although housing can be complex, there are common approaches for improving outcomes.

Tese campaigns have had varying success: some programmes have demonstrated lasting change. Evidence from Melbourne (Australia) found that, during periods of draught, diferent education campaigns played a critical role in reducing water consumption. Te voluntary 'Target 155 L' campaign, which was introduced in Melbourne in 2008, used a range of advertising and education to encourage residents to reduce their daily water consumption to under 155 litres per person (40% lower than average consumption of only a few years previous). Analysis found that the campaign was quite successful with consumption not only dropping to the desired level but also remaining at that level for several years following the campaign's formal end [90]. More than ten years after the campaign started, the average water consumption in Melbourne remains around 160 litres per person [91]. One of the ongoing challenges for education campaigns, as with any changes to practices or lifestyle, is that it can take a long time for people to develop new energy or water efcient practices and, unless the education campaign is sustained or repeated, the benefts can decrease over time.

Tere has also been a rise in open house style events for sustainable housing, which have both acted as a way educate consumers and demonstrate what is possible [92]. Or, as Martiskainen and Kivimaa [93, p. 28] put it, such events create a 'space for initial visioning by sharing experience from completed projects'. Seeing real life examples helps translate ideas and knowledge [94], so these open house experiences are important for both learning what has worked and identifying what has not, as well as learning how to improve the overall process.

In conjunction with raising awareness through education campaigns, product labelling programmes, such as Energy Star, have provided consumers with improved information to aid purchasing decisions. Te Energy Star programme was developed in the USA in 1992 to address increased energy from appliances, particularly in dwellings, and it is widely regarded as one of the more successful government energy efciency programmes [95]. Systematic improvements to the programme have seen minimum energy efciency standards of appliances increase over recent years. Since its inception, the Energy Star programme has helped save more than 5 trillion kWh of electricity and reduced greenhouse gas emissions by 4 billion metric tons [95]. Te programme has also seen signifcant fnancial savings with more than US\$42 billion in 2020 and more than US\$500 billion in avoided energy costs since the start of the programme. In addition to Energy Star for product labelling, there has been an Energy Star certifcation for homes which has seen more than 2.3 million homes certifed to its performance level since 1995, resulting in housing that is at least 10% more energy efcient compared to building code requirements [96]. In 2020 alone, this programme (Energy Star) saved 3 billion kWh of electricity, avoided US\$390 million in energy costs, and achieved 4 million metric tons of greenhouse gas reductions [96]. Similar benefts have been seen elsewhere; for example, energy efcient appliances are saving New Zealanders more than NZ\$30 million a year, with estimated economic savings of NZ\$1.5 billion since 2002 [97].

A further approach that has been used with varying success is the use of rebates or tax incentives for energy efcient technologies or building practices. For example, from 2007–2012, the UK ofered signifcant stamp duty (land tax) reductions to encourage consumers to purchase new housing that exceeded minimum performance regulations in a bid to reward early adopters of the higher energy performance standards [98, 99]. Tis may have helped reduce costs to deliver zero carbon homes in the UK by around 8% across the frst four years of the Code for Sustainable Homes programme [100].

In Australia, rebates (including upfront and as a credit for excess energy) have seen the rapid uptake of residential solar photovoltaics (PV) to the point where more than one third of homes now have a solar system—a change that happened in less than a decade. However, there have been challenges with the various fnancial support programmes, and when the rebates or other fnancial supports have been too high, the programmes have often seen an over-subscription of uptake which has led to issues around the quality of some systems being installed. Te frequent changes to the amounts received for excess energy and the feed-in-tarif has fuctuated over the years and, depending on it if is higher or lower than the cost for consumers to purchase standard energy, it starts to change the way the systems should be used to maximize fnancial outcomes. For example, if the feed-in-tarif is high, then it benefts households who are out of the home during the day and can sell as much energy as possible; whereas, if the feed-in-tarif is low, it is better for that household to consume as much of the energy they are generating as they can.

Rebates, and other innovative fnance options, have been identifed as particularly important for the retroft of existing dwellings. To date, much of the retroft undertaken across the world has, outside a few key government programmes, largely been driven and funded by individual households. Typically, banks and other signifcant investors have been reluctant to drive this funding. Some examples of where this is occurring include the Property Assisted Clean Energy fnance programmes in the USA and low cost loans delivered by the German KfW state bank [101]. Brown et al. [101] discuss how meeting future climate challenges will require signifcant alternate funding and easier access to funding for retrofts.

# **2.6 Conclusion**

Sustainable housing ofers signifcant opportunities to improve outcomes across a range of environmental, social, and fnancial metrics. Tere is increasing evidence that we can (and should) be delivering much higher design, quality, and performance for new housing and signifcant deep retrofts for existing housing. However, as we explored in this chapter, there have been signifcant market failures around sustainable housing. Tis is important to understand not only because it provides a context for how we have been addressing housing design, quality, and performance (largely through inadequate building codes), but also because it identifes the opportunity for change. We discussed some of these key policy mechanisms, including the setting and improvements of minimum performance requirements in building codes, the use of planning systems to require additional sustainability requirements, and the development of fnancial and other support. Tis sets the context for later chapters where we explore the range of challenges facing the housing sector and discuss current best practice in sustainable housing and policy.

#### **References**


*and the governance of socio-technical networks.*, S. Guy, et al., Editors. 2011, Earthscan: London.


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# **3**

# **A Critical Juncture**

### **3.1 Introduction**

In Chap. 1, we explored the benefts of sustainable housing for individual households and for society. We also discussed why, as a global community, we need to transition to sustainable housing for a low carbon future. As Chap. 2 outlined, many jurisdictions have made improvements to the design, quality, and performance of new and existing housing over recent decades, primarily driven by the creation of minimum performance standards.

Despite this progress, we are at a critical juncture for what type of future we are creating. If low carbon and broader sustainability outcomes are to be achieved by the middle of the century, we know that the time before 2030 is going to be critical, with potentially even less time than this. Te most pressing issue in the wider sustainable housing debate relates to climate change and the ability of the housing sector to contribute to a low carbon future. Tis is not the only reason why there is an urgency for change though, with an increasing range of social and fnancial drivers challenging traditional thinking, policy, delivery, and use of housing.

Tis chapter explores why we are at this critical juncture where we need to make urgent changes (Sect. 3.2). Tis applies to both new housing and the need to address existing housing. If done right, a transition to sustainable housing will not just be about improving design, materials, technologies, and construction methods, but will also be a way to help address a range of other social justice and equity issues that have been exacerbated by rapidly worsening housing unafordability and access issues around the world. We discuss this through innovations in sustainable housing as pertaining to the wider sustainable housing transition (Sect. 3.3). We return to the ideas and case studies of sustainable housing innovation in Chaps. 6 and 7.

## **3.2 An Urgency for Change**

Globally, there has been increasing tension between the impact that humans are having on our natural climate and the way we are responding (or need to respond). While, for many decades, the housing construction industry and some policy makers have expressed intentions to deliver 'sustainable development' (as defned by Brundtland in 1987), there has been very little change to overall practices in many jurisdictions. Tis is especially concerning given that there has been a signifcant increase in population and consumerism since these ideas emerged, as well as related ideas from the 1970s (e.g., Limits to growth report and the establishment of the United Nations Environment Program), that makes the challenge of achieving a U-turn on relatively unchecked emissions growth a signifcant challenge. Cohen [1, p. 174] states there is 'growing recognition that the greenhouse gas reduction targets of the Paris Agreement and the objectives of the United Nations 2030 Agenda for Sustainable Development will be unachievable if policy initiatives continue to be predicated on incremental adjustments that only superfcially mollify the most egregious aspects of contemporary norms'.

While there have been a range of mechanisms, such as minimum building performance requirements, introduced over recent decades, they have tended to be incremental and have been generally disconnected from what is considered best practice by the community of sustainable housing researchers and advocates [2]. Te type of sustainable housing that will be required to achieve a low carbon future is housing that achieves signifcantly improved environmental, social, and fnancial outcomes. In this book, we defne sustainable housing as dwellings with a zero carbon impact that, where possible, contributes to regeneration initiatives that support wider sustainability. Sustainable housing is housing which signifcantly reduces its life cycle impacts and engages with concepts of the circular economy (e.g., design for disassembly). However, it is more than just physical elements; sustainable housing improves health and well-being, reduces living costs, and connects to other sectors such as transport, food, and energy networks. Sustainable housing draws on a variety of design, material, technology, and construction innovations to build housing that will perform well now and into the future. Tis is not just performance from a technical perspective but also in terms of resiliency against a changing climate (e.g., resilient to extreme weather events).

Tese elements should be the minimum considerations for sustainable housing moving forward and we can achieve them right now (see Chaps. 6 and 7 for case studies). Innovations will likely mean our defnition of sustainable housing will change in future years but will also likely lead to improvements in how sustainable housing can be provided. Tis dynamic consideration of sustainable housing means it is hard for a global defnition, and a defnition will also be dependent on context specifc factors such as local climatic conditions. An increasing number of examples over the past two decades have demonstrated that there are no design, material, technological, and construction method reasons why we are not delivering these types of dwellings already.

While much of the broader policy discussion around the world has been on how the housing sector can achieve low carbon outcomes by 2050, the transition could happen much faster if the housing construction industry and other key stakeholders voluntarily engaged. We can see this voluntary change currently happening with electric vehicles. Since 2017, there has been a plethora of car manufacturers announcing their plans to transition to only selling electric vehicles. Tese manufacturers are setting even more ambitious timeframes than many government policies and pathways for increasing the uptake of electric vehicles, demonstrating that change can happen quite quickly when there is a desire to do so.

#### **3.2.1 Locked In**

Housing is infrastructure with a long life, lasting many decades if not 100 years or more. In relation to sustainability, the decisions made around design, materials, technologies, and construction methods are critical for determining a dwelling's quality and performance outcomes and the way it will be used by occupants. An old rule of thumb suggests that 80% of a dwelling's impacts are locked in during the frst 20% of the design process, but the early considerations around land use and planning can also impact the future opportunities for improving design, quality, and performance. Once a dwelling is built, it can be costly to retroft to improve design, quality, and performance and the options to improve outcomes are limited by the existing building. For example, if the dwelling is not orientated the right way there is little that can be done to improve orientation, potentially reducing the benefts that could be achieved via passive solar design.

Data from the UK indicates that it is likely to cost £20,000 or more to retroft many existing dwellings to achieve a low carbon future [3]. Housing performance in the UK is arguably starting from a higher base level than many other countries given the high uptake of some more costly retrofts for various sustainable housing elements such as doubleglazed windows (over 80% uptake) [4]. Conversely, in Australia, there has been a low uptake of double glazing meaning that any retroft becomes signifcantly more expensive with the need to undertake more disruptive work. Research from Australia has found the cost of deep retrofts to be in the range of AU\$25,000–\$50,000 [5–8].

As noted by researchers across several countries, the housing that already exists will make up most of the residential building stock in 2050 [7, 9, 10]. Addressing the existing housing stock will take a signifcant efort and there are diferent challenges to achieving sustainability outcomes compared to new housing (e.g., ease of work). Terefore, we must make sure that whatever new housing we add to the current stock is delivered to the highest design, quality, and performance standards possible to ensure we are not locking in future housing and households to poor sustainability outcomes and the need to undertake expensive retroft in the coming decades.

Te challenge for the housing sector is how to provide the type of housing that is required now and into the future. Tis is not a straightforward proposition when what we want from housing, or the way we use it, may change. We have seen this occurring over recent decades with some developed countries, such as the USA and Australia, seeing rapid increases in the average foor area of detached housing as part of the perception that consumers wanted more (more bedrooms, more bathrooms, more hobby rooms). However, this increase in foor area occurred while average occupant numbers were decreasing, creating an odd paradox. Incremental improvements to energy efciency technology are often being outstripped by a rapid overall increase in energy consumption. Tis is referred to as the rebound efect and it occurs because of the increasing number of appliances and changes to their use [11, 12]. Tese changes have created mixed results related to the sustainability of new and retroftted housing, even though minimum performance requirements have steadily been improving.

What we want, or need, in our housing can shift quite quickly. For example, the emergence of COVID-19 resulted in many cities experiencing periods of lock down to try to control the spread of the virus. Tis meant people spent more time in their homes. For those who could work from home, the home became a blurred line between where people worked (or studied) and where they lived. It also resulted in people creating makeshift work-at-home spaces that were not designed for such use. Many people who had to spend more time at home realized that their housing is hard and expensive to heat and cool, or that there are a range of defects that impact liveability [13]. Tis is for those who are lucky: renters or those on low incomes have found that the pandemic exacerbated many of the pre-existing issues around housing quality and afordability. Additionally, during COVID-19, people who were homeless, who were in shared housing, or who lived in informal housing faced far more serious problems which were exacerbated by their access (or lack of access) to safe and reliable housing.

Because of climate change, we have seen more frequent and more extreme weather events such as extreme heat, fooding, and bush/forest fres since the early 2000s. Tese climate change impacts and related events inevitably impact housing. Higher temperatures lead to increased use of mechanical cooling systems to stay cool. Flooding can seriously impact the structural integrity of property and can damage homes and their contents. Bush and forest fres can completely decimate homes and infrastructure. Tis kind of weather related property damage impacts housing afordability and household fnance. Research in the USA found that homes in California sold for an average 3.9% lower in wildfre prone areas compared to lower risk regions [14]. Te cost of insurance has also gone up, and in some locations, homes have become uninsurable due to increased risk of fooding or fres. For example, between 6–10% of homes in Canada are not eligible for food insurance because the locations have been deemed too high risk by insurance companies [15].

Every year that a sustainable housing outcome is delayed, it will continue to lock in households and the housing sector into less efcient housing. Research in Australia has calculated that the cost for delaying regulatory minimum performance requirements for new housing from 2019 to 2022 would impact 500,000 new dwellings built across the three years and result in AU\$1.1 billion of unnecessary energy bills for households by 2050 [16]. Te impacts were found to be wider than just individual households, with research estimating that the delay in improving minimum performance requirements would lock in AU\$530 million of unnecessary energy network investment. If these fgures are extrapolated to other jurisdictions, the global cost for inaction in delivering sustainable housing will run into many tens of billions of dollars each year, if not hundreds.

#### **3.2.2 Timeframes and Targets**

In relation to broader sustainability goals, there is global consensus that we are facing a climate emergency and must achieve greenhouse gas emission reductions of at least 80% by 2050, if not sooner [17]. Many countries have, after decades of avoiding signifcant action, set out interim targets to ensure a pathway towards this goal. Tis 2050 greenhouse gas emissions reduction target is considered the minimum of what must be done by many in the scientifc community, and even if it is achieved, it does not guarantee that there will not be signifcant changes to our climate. Realizing the urgency, an increasing number of countries have revised their time frames and targets in recent years. Tis has also been seen in the business space where a number of companies have announced their own environmental targets. However, there remains a signifcant number of countries who have been reluctant to make such commitments or to adhere to calls for higher targets across a shorter time frame, making global progress towards a low carbon future challenging.

As discussed in Chap. 1, the built environment is a signifcant contributor to overall greenhouse gas emissions. Tis is both through the consumption of materials during the construction and through consumption of energy during the dwelling's use. As a reminder, the housing sector is responsible for 17% of the world's greenhouse gas emissions and 19% of its fnal energy consumption [9, 18]. Tis impact is even wider if we include transportation impacts from housing location.

However, the good news is that the housing sector has been identifed as low hanging fruit by a range of researchers, industry stakeholders, and policy makers. Tis means we can cost-efciently deliver sustainable housing right now. Tis is demonstrated in established and emerging examples of new housing from all around the world. Tis is also the case for retroftting existing housing where signifcant improvements in performance can be achieved cost-efectively, such as through sealing all gaps and cracks and installing insulation, delivering improved sustainability and social outcomes, not just for the occupants but for society.

Prior to climate emergency declarations, in 2015 the UN announced their Sustainable Development Goals which are also driving change in the housing sector. Tese 17 goals aim to address a range of inequity and justice issues across the world. Several relate specifcally to energy and the built environment such as goal 7 (Afordable and Clean Energy), goal 11 (Sustainable Cities and Communities) and goal 13 (Climate Action). Tese Goals demonstrate that a transition to sustainable housing is not just about housing in developed countries switching from fossil fuel to renewables. Tere are signifcant parts of the world where even the provision of basic housing is an ongoing challenge such as the 1 billion people who currently live in slums or informal settlements [19]. A transition to a more sustainable, afordable, and safe housing future for these populations means the provision of safe and decent housing, with quality and sustainability outcomes helping to improve a range of fnancial and social impacts. Te timeframe set by the UN to achieve these outcomes is 2030, which at the time of writing this book is less than a decade away.

Typically, the development of minimum design, quality, and performance requirements has happened in small increments. Tis ensures that progress is being made but that the change is not so large that it adds unreasonable costs or burdens to consumers or the housing construction industry. However, there have been several examples where there has been a shift to longer term policy development as it relates to housing performance regulations. As discussed in Chap. 2, there are several jurisdictions that have made more signifcant progress towards sustainable housing by setting out longer term policy pathways for how it can be achieved. In California, policy makers set out a ten-year pathway to improve housing design, quality, and performance requirements in stages. Tis provides an example of how long it can take policymakers, and the construction industry to transition to a sustainable housing outcome. In British Columbia, the government introduced the BC Energy Step Code, a voluntary tool that provides an incremental approach to obtaining energy efcient buildings that go above the base requirements of the BC Building Code. Te Energy Step Code also provides a pathway for ensuring all buildings province-wide are Net-Zero Energy Ready by 2032. Most countries, however, have not yet introduced requirements to achieve such housing outcomes, with current minimum performance still falling short of what is required for a transition to a sustainable housing future. Even when such outcomes are intentionally set, there is still a lack of pathway development to achieve them [20–22].

Several other locations, such as Australia, have recently developed, or are in the process of developing, longer term policy pathways to deliver sustainable housing and wider low carbon outcomes. Tese longer term pathways are important for a range of reasons, including that they provide more certainty for the housing construction industry and associated stakeholders about what the future holds. Tis provides an incentive for the housing construction industry to fnd a way to innovate and deliver the improved performances, while also providing time between each step to allow the industry to adapt. It also helps provide a clear reason for those who want to innovate to do so.

While globally there is a range of longer term sustainability goals relating to reducing greenhouse gas emissions by 2050, there has been a lack of specifcity around housing's role in reducing these emissions in many jurisdictions. As a global society, we must aim to address this and move to delivering sustainable housing outcomes as soon as possible.

Te jurisdictions that are already doing this, or are close to, are showing that this is not a pipe dream and that it can be done now if the political and industry will is there. While some jurisdictions will be coming from a low base for housing quality and performance, it is not unrealistic to think that the majority of new housing (and buildings more broadly) can be delivered to such outcomes no later than 2030. Tis would not only align to the wider UN Sustainable Development Goals, but would help to reduce the impact of all new housing from 2030 onwards to try and achieve the 2050 sustainability goals.

Te retroft of existing dwellings is more challenging [3, 7, 23, 24]. As part of the push towards a low carbon future, the UK Climate Change Committee stated that the residential stock needed to be nearly completely decarbonized by 2050 [3]. Based on their dwelling performance rating scale of A (best) to G (worst) in 2018–2019, there were around 19 million dwellings across the UK that had a rating of D or worse. With calls to lift these dwellings to at least a performance of C over 10–15 years, this would mean that homeowners would need to complete almost 2.5 retrofts every minute for 15 years [3]. To achieve this, it has been estimated that retroftting existing housing would require more than £70 billion in total investment, although diferent estimates put the costs at 3–4 times this amount depending on the level of retroft and the number of hard-to-treat homes [3, 23]. To achieve the nearly zero emission outcomes would require even deeper retrofts and include more of the housing stock. Similarly, high numbers of retrofts will be required in other jurisdictions, presenting a major challenge for how this will be delivered.

#### **3.2.3 Green New Deals**

Te issue of how to deliver sustainable housing is not just about the design, materials, technology, and construction methods; it is also about having a housing construction industry that can deliver these outcomes. Tere are concerning labour shortages in both the new and existing dwelling sectors in many jurisdictions [25, 26]. Tis has been a bubbling issue in many countries for several years, resulting in constraints over the number of new dwellings that can be constructed, dwellings that can be retroftted, and the capacity to scale up changes. It also limits the opportunities for any additional industry requirements, such as training for how to deliver improved design, quality, and performance, given the industry is already over stretched. While we generally have the knowledge to deliver sustainable housing, there is still a need to educate the vast majority of the industry about the practices they would need to change or modify in order to deliver sustainable housing.

Te ongoing labour shortage issue has led to a chronic undersupply of housing in countries like Australia, which has contributed to worsening housing afordability due to less supply than demand. Tis in turn plays a role in discussions around design, quality, and performance. As the argument goes, improving design, quality, and performance will add costs to a dwelling which makes it even less afordable. Tis kind of thinking prevents improvements from happening, locking in the poor sustainability performance of a dwelling for decades (or until the household or homeowner undertakes a costly retroft), creating a perpetual cycle where key housing issues are never properly addressed.

In response to the global fnancial impact of the COVID-19 pandemic, there has been an increasing number of research and policy analysis reports that have outlined how economic recovery should have a greater focus on sustainability. In fact, this research argues that more jobs will be created through a sustainability focus than any attempts to return to a business-as-usual approach. It should be noted this is not the frst time such a plan has been put forward, with similar calls made after the Global Financial Crisis in 2008–2009.

In their Sustainable Recovery Plan analysis, the International Energy Agency outlines how a focus on a green recovery would save or create more than 9 million jobs a year from 2020–2023 [27]. Te report estimates that 9–30 jobs would be created for every million dollars invested in energy efciency measures for buildings. Te report, as with others noted below, takes a more holistic approach to the call for a green recovery, highlighting the signifcant benefts related to lower energy bills, reduced energy poverty, and improved health and well-being outcomes. Tis is not just about improving housing quality and performance of developed countries, with the plan identifying a need to provide access to clean cooking to the more than 2.5 billion people that still have to cook with inefcient and polluting fuels like biomass and coal. Tis is about addressing polluting energy sources as well as improving health outcomes for such households. Te broader impacts would not just be from providing jobs but also from a recovery that would be better for the environment. Te recovery from the 2008–2009 Global Financial Crisis saw greenhouse gas emissions rebound as the global economy started to grow again. In contrast, the Sustainable Recovery Plan aims to reduce greenhouse gas emissions by 5% while creating jobs.

Major research in other parts of the world has identifed similar benefts. McKinsey estimates that a green recovery will not only reduce emissions by up to 30%, but also create 3 million more jobs over the coming years than traditional employment would [28]. Te authors estimate that for every million dollars in spending, 7.5 renewable energy jobs or 7.7 energy efciency jobs would be created, compared to only 2.7 jobs in the fossil fuel sector. In total, they estimate up to 1.7 million jobs could be created to retroft housing for energy efciency.

In the UK, Greenpeace estimate that for every million pounds invested in the sustainable building sector, 23 jobs would be created for a total potential of 400,000 new jobs [29]. Tese jobs are to be created across the entire sector, but the retroft of existing housing and provision of new sustainable housing is noted as a key driver of these jobs.

Te retroft of existing housing is a key theme in these green recovery plans. In France, there are plans to scale up retroft to undertake 500,000 energy efciency retrofts per year, half of which will be low-medium income households [30]. To achieve this outcome, funding will be provided by the government to train new and existing housing construction industry employees. Similar benefts from a green recovery have been put forward in Australia where a signifcant focus on retroft of existing housing could make 2.5 million existing homes more energy efcient across a 5-year period [31]. At an estimated cost of AU\$25,000 per home, the deep retrofts delivered would signifcantly reduce utility bills and improve liveability outcomes for occupants. Tis retroft programme would create up to 500,000 jobs across the fve years and help kick-start a longer term retroft programme in Australia. In addition, there could be another 440,000 jobs in the new housing space through a focus on delivering an increased number of social housing units. Tis programme would also lead to signifcant environmental improvements with an estimated 20 million tonnes of greenhouse gas emissions avoided.

#### **3.3 Innovations in Sustainable Housing**

We are at an urgent junction in time where signifcant steps must be taken by 2030 if the housing sector is to address a number of critical issues: not just the broader environmental challenges, but also those relating to equity and justice in the housing space. In Chaps. 6 and 7, we will explore some case studies of what is currently being done in diferent regions of the world as it relates to sustainable housing. Below is an overview of some examples of innovations that have emerged in recent years that show us what we could be doing in relation to sustainable housing.

Related to rapid improvement of sustainability outcomes at the dwelling scale, one of the most widespread examples we have seen around the world is the uptake of residential solar PV since the early 2000s. Countries like Germany, Spain, and Australia have seen residential uptake of PV skyrocket. In Australia, in just over a decade, the percentage of dwellings that now have PV went from less than 1% to around one third of all dwellings [32]. While very much a technical sustainability fx, and arguably, not the frst priority to consider when delivering sustainable housing, the fact is PV has shifted ideas and thinking around energy and housing. Tis shift has helped create a narrative around high cost of living and the options to address it (i.e., sustainable housing) with households able to make a direct link between having PV and the impact on their energy bills.

Te success of PV has been created through various policy developments, government rebates, and industry innovation which have resulted in higher performance at a lower cost. Once the fnancial tipping point was reached, the foodgates opened in some countries and PV panels went from being a niche sustainability item for hippies living of the gird, to being normalized across the wider housing public [32]. PV panels have shown what can be achieved in a relatively short period of time. Tis rapid uptake has also laid the groundwork for future technology development and roll outs such as battery storage and electric cars, which are attempting to draw on the successful pathway of PV panels.

PV and battery storage are not without issues. Tese include questions on the environmental and social impact of mining the raw resources used in the technologies, poor quality products, dodgy PV retailers and installers, issues with intermittent energy loads on energy networks, and ongoing arguments about why governments are continuing to provide fnancial support (through rebates for capital costs and/or feed-in-tarifs). Despite these challenges, PV continues to grow in popularity as evidenced by evidenced by the ongoing uptake in countries like Australia when fnancial rebates have been removed1 [32].

PV panels are seen as an easy "bolt on" sustainability solution, which means households get the beneft of reduced energy bills without having to change the way they use their housing. Outside of environmental and afordability benefts, PV panels are also critical to rapidly improving quality of life for the 733 million people without access to electricity or the 2.4 billion people who still use inefcient and polluting cooking systems [34]. Te provision of even a small number of PV panels can not only improve quality of life for people, but can improve wider fnancial markets for communities [35, 36].

Double-glazed windows are another example, where in select regions of the world there has been signifcant uptake. In the UK, Europe, and

<sup>1</sup>While the topic of rebates to help deliver sustainability technology or to shift the industry is often a political tension point, often overlooked is the US\$5900 billion of subsides provided to fossil fuel energy generators each year [33].

Canada, performance requirements mean most new housing has double glazing at minimum, with trends moving towards triple glazing. In British Columbia, the use of double or triple glazing is often dependent on the region; the south coast uses double glazing more regularly while colder regions are more likely to look for higher performance outcomes and choose triple glazing. As stated earlier, more than 80% of housing in the UK now has double glazing [4]. Te uptake of double-glazed windows began in the 1970s when the industry started to establish itself. However, the role of policy and performance regulations is clear with government analysis stating that 'Tis [recent uptake] is mainly because, since 2006, Building Regulations have stipulated that all windows in new dwellings and most of those that are replaced in older dwellings should be double-glazed' [37, p. 30].

Policy makers have generally struggled with how to deal with existing housing in terms of how much direction governments can impose onto households and their dwellings, especially if such dwellings have been built, bought, or rented prior to the introduction of any sustainability improvement requirements. In addition to regulations for double-glazed windows, there are other examples of where regulation has been able to create improved outcomes. For instance, in 2014, the City of Vancouver introduced Canada's frst bylaw with energy upgrade requirements for existing buildings. Te City required housing renovation projects to acquire a demolition permit with obligations to re-use and recycle some of the materials. Tere have also been other notable developments in the retroft space including the German Energiesprong programme, which now operates in Germany, France, the Netherlands, and the UK and leverages private fnancing to deliver afordable zero energy retrofts with the borrowed money repaid through the energy savings [22].

For rental units, an increasing number of countries are setting various improved minimum performance requirements any time a dwelling is listed for rent. For example, since 2019, the UK has required landlords to invest up to £3500 in rental properties that have Energy Performance Certifcate ratings of F or G in order to improve the quality and performance of the dwelling to at least an E rating when it is next up for lease [38]. It is estimated that this requirement will impact just over 6% of dwellings in the UK. If this approach is successful, it is likely that these minimum requirements could be lifted to capture a wider proportion of the housing market, much like how new housing requirements have been periodically increased. Tis type of policy aims to address the issue that rental housing tends to be in poorer quality, older, and less sustainable. Tis is not true for everywhere but is prevalent in countries that have lower amounts of rental stock and do not have incentives for landlords to improve the performance and quality of rental housing (e.g., Australia).

In recent years, there has been more development of alternative mechanisms to improve design, quality, and performance of housing that goes beyond minimum building code requirements. Tese include "good design guidelines" that set minimum requirements for elements not typically considered within the building code. In Australia, there has been ongoing challenges with delivering good quality design, usability, and performance in the higher density dwelling space. Examples of poor design in apartments in Australia include bedrooms with no windows and poor ventilation. In an evaluation of recently built apartments in Melbourne, researchers found that no high rise apartments (over 16 storeys) met good design requirements, and only 11% of medium rise apartments (6–15 storeys) did [39]. In response to wider issues with apartment design and quality, New South Wales introduced the State Environmental Planning Policy No 65—Design Quality of Residential Apartment Development and associated Apartment Design Guide, and Victoria introduced the Better Apartment Design Standards. Tese standards set out requirements for things such as minimum requirements for certain room types, minimum amounts of storage, access to certain number of hours of daylight, and even things such as requirements for communal spaces.

Additionally, good design guidelines and regulations are increasingly engaging with requirements around life cycle thinking. Tis is reshaping how we consider the materials used within our dwellings, moving it away from just the construction phase and towards thinking about designing for longer life, ease of maintenance, and disassembly and re-use at the dwelling's end of life. For example, prefabricated housing is a newer construction technique that is improving material efciency through precision construction and the ability to have greater control across the construction process. It has been reported that prefabricated housing can reduce the amount of materials/waste in a dwelling and result in shorter construction times which can potentially help to address the undersupply of housing [40].

As part of this increased focus on design, there is a section of the housing market that is demonstrating that you can get improved function from housing without having to increase a dwelling's foor area. At the extreme, the tiny house movement is demonstrating what can be done with very little space. While this is not for everyone (with spaces as small as 7m2 and up to 40 m2 ), it does demonstrate what a focus on design and function can do to help deliver improved functionality in a smaller footprint. Tis has many benefts such as reducing initial construction costs and the costs from ongoing maintenance and use (such as reducing the need for heating and cooling a larger area). Part of the challenge is that the housing construction industry in many locations is not required to engage with people who have the skills to be able to deliver these types of outcomes. Architects in particular have a critical role to play in a transition to a sustainable housing future [41, 42]. For example, an architect in Melbourne presented a case study of two similar detached houses that were built for a single client on two similar blocks of land in the same location [43]. One of the houses was designed by a draftsperson with the other designed by the architect. Te architect argued that their own design improved the function of the dwelling and reduced construction costs; they reduced "wasted" hallway space by 5% which resulted in reduced construction and labour costs by around AU\$18,000. Another beneft of using the architect was that the house received approval for construction quicker than the draftsperson's design.

Another trend emerging to improve the design, quality, and performance of housing is smart homes [44–46]. A smart home typically will use a range of internet and wireless connections between devices and appliances to control certain things within the home. Tis could range from delaying the start of a washing machine until there is sufcient sun to cover the energy required for operating the machine, through to automatically opening/closing windows and blinds and turning on/of heating and cooling systems. Smart homes promise a range of benefts, such as improved energy and indoor air quality performance, lower energy costs, extending the life of appliances, automatically organizing maintenance, and identifying and fxing issues of underperformance [47, 48]. For example, if a PV system is not working or underperforming, a smart home can alert the owner to have the PV system checked. Tere are examples where people have not realized their PV system was not connected or working for multiple months due to not having the ability to access performance information in real time (or being unable to interpret the data of information they could access) [49]. Some reports cite people missing out on six months or more of renewable energy because they (or someone else) only realized their system was not working after several quarterly energy bills had been issued.

But the potential benefts implications of a smart home go beyond the boundary of the home itself. Energy policy makers in particular are increasingly looking towards what opportunities there may be to control energy loads at a household and neighbourhood scale during certain energy events such as peak energy during a heatwave. By regulating how many air conditioners are operating, energy network operators believe there will be less costs associated with generating peak energy and a reduced amount of blackouts. It is also potentially a way to distribute energy restrictions more evenly across a larger range of households for a smaller period of time, which could avoid rolling blackouts. Recent years have seen notable energy challenges with large scale energy network blackouts during extreme weather events (e.g., Texas, USA). However, there are technical and ethical issues around the smart home (e.g., how does a house operate if the internet go down? or, what happens to your data?) and around allowing energy companies control over what you do, or do not do, within your home. As Maalsen [44, p. 1545] states '[t]he increasing ways in which smart is reconfguring housing and home means that we need to pay greater attention to the smart home's political, material, social and economic mechanisms and the way these produce and reshape the world'.

In contrast, some innovations are directly pushing back on more technology or a smart home driven approach, and are re-engaging with older ideas of housing design, quality, and performance. For example, the shift towards mechanical heating and cooling has been a more recent shift, with occupants previously taking a more active role in managing heating and cooling on their own. Practices such as opening and closing windows and blinds or sleeping out on porch on a summer evening were key methods to managing warmer months in many parts of the world [50–52]. As we move from active to passive housing, we are losing many of these ways for managing our homes. Oral history research has shown how peoples' practices, especially as they relate to heating and cooling, have changed over time; however, this research also shows that there are increasing examples of occupants re-engaging with active home management practices [53]. Additionally, research has shown that ideas like adaptive thermal comfort show people can be quite comfortable in a much wider range of temperatures [50–52, 54]. Tere are an increasing number of examples where these more passive thermal comfort options are being prioritized over more active systems. General improvements to design, quality, and performance allow for these types of outcomes.

Te role of sustainable housing is starting to move beyond traditional framings of housing and is engaging in the social benefts which such housing can provide. For example, in the UK and New Zealand, there have been various programmes where doctors were able to prescribe energy efcient retroft to address health and well-being issues for vulnerable people [55]. Or Finland's housing frst principle which argues that you give a homeless person a contract to a home, a fat, or a rental fat, with no preconditions. Tis is arguably a more holistic way of thinking not only about health and well-being but also about housing. For housing, we are increasingly able to measure the social and health improvements such as reduced trips to doctors, less sick days of work, or the ability to tackle chronic conditions. Once measured, we can include these social and health improvements in the wider analysis on the costs and benefts of sustainable housing.

## **3.4 Conclusion**

As a global society, we are facing a critical juncture. Not only do we urgently need to address the climate emergency, there is also a range of growing societal challenges that are negatively impacting a growing percentage of the population. Sustainable housing ofers an opportunity to not only make a signifcant contribution to a low carbon future but also address issues such as poverty and health inequities.

For too long, the push towards sustainable housing has been diluted and challenged by vested interests within current housing regimes around the world. Te industry has largely been wanting to continue business-asusual operations, and would prefer less government intervention and for the "market" to decide what design, quality, and performance outcomes are desired. However, this approach has largely failed, and a new approach is needed if we are to avoid locking in millions more households, and our wider society, into a sub-optimal housing future.

While there are a range of challenges in trying to deliver sustainable housing, the innovations and examples presented in this chapter, and the increasing number of real-world case studies, demonstrate that we have the design, materials, technologies, and construction methods to be doing much more related to improving the design, quality, and performance for new and existing housing. In the next three chapters, we will explore the idea of a sustainable housing transition in more detail and present a range of case studies demonstrating various sustainable housing outcomes.

#### **References**


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# **4**

# **The Sustainable Housing Challenge**

# **4.1 Introduction**

In Chap. 1, we explored the broader context as to why there was an urgent need for the provision of sustainable housing as part of a wider transition to a low carbon future. We discussed what sustainable housing is and the range of environmental, social, and fnancial benefts that such housing can provide both at the individual household level and at larger urban scales. In Chap. 2, we outlined how housing design, quality, and performance has typically been addressed around the world, that is through the setting of regulations for minimum thermal and energy performance of new and existing housing. Te introduction of such regulations has arguably been the biggest driver of improvements to dwelling performance over the past 30 years. However, despite the evidence on the benefts of sustainable housing and the role that such housing will play in a transition to a low carbon future, progress in improving the design, quality, and performance of new and existing housing around the world remains below where it should be and below where it needs to be to meet future sustainability goals such as the 2050 emission reduction targets. Building upon this, we discussed in Chap. 3 the critical juncture we are currently at, and the importance that the time leading to 2030 will play in shaping the direction of the sustainable housing transition to a low carbon future.

In this chapter, we build upon the disconnect between what we know is required for housing design, quality, and performance and what we are currently providing. Te chapter explores why this is the case by looking at historic, current, and future challenges that contribute to holding back a sustainable housing transition. Te chapter is not intended to be an exhaustive list of challenges, but rather attempts to highlight the range of challenges across diferent domains (e.g., technical, fnancial, knowledge, practice). Naturally, not all these challenges will be relevant everywhere and every location will have a more nuanced set of challenges relating to things such as climate and the existing urban context. Te intent here is to highlight some of the common challenges to help us develop an understanding of the types of things we need to address in order to scale up the provision of sustainable housing. Some of these challenges are deeply complex and play out differently at diferent scales. We structure the discussion in this chapter around the scales where decisions are typically made: the dwelling scale (Sect. 4.2), the neighbourhood and city scale (Sect. 4.3), and the state, national, and international scale (Sect. 4.4). We then discuss the wider residential market and the unwillingness to change (Sect. 4.5) and the interconnected complexity of such change (Sect. 4.6).

## **4.2 Dwelling Scale**

Tere are well-established elements that contribute to providing a sustainable dwelling, including considerations around design, materials, technologies, and construction methods and the way the dwelling is used by occupants across its life [1–5]. When basic sustainable design principles, such as orienting the dwelling to maximize use of passive solar design and natural ventilation are included in the initial design of a dwelling (or even before that, in the planning for property lot layouts) sustainable housing outcomes can be maximized for little (<10%), if any, additional fnancial cost [6–9]. However, despite the technical understanding of how we can provide sustainable housing in diferent climate zones, and the increasing number of real-world case studies of how to do this (see Chaps. 6 and 7), challenges remain at the individual dwelling and site level in many jurisdictions, which can make it difcult to provide improved sustainability.

#### **4.2.1 Planning and Design**

In many developed countries, there is some form of planning process involved in the provision of housing (see Chap. 2). In addition to the ability to set local requirements for design, quality, and performance, planning systems have a critical role in deciding how land is used and where development should occur [10–13]. Te decision of what land can or cannot be used for has important implications for environmental, social, and economic outcomes for a range of stakeholders. For example, the planning system can set parameters for areas that are to have higher, or lower, density development which then immediately infuences the type of housing that can be provided, as well as its afordability. In other areas, the rezoning of land from industrial or agricultural to residential can unlock signifcant fnancial value for the landowner. Furthermore, it is in the planning system where decisions on climate risk typically sit, such as determining if dwellings should be built in an area with a particular climate risk such as fooding or bushfre. Tese planning system decisions present opportunities for improvement of design and sustainability outcomes but can also create negative outcomes if not done properly. For example, after signifcant fooding events through urban centres on the east coast of Australia in 2022, it was revealed that many local planning authorities were using historical climate data to make decisions about food risks. Some researchers suggested that this had led to some houses being built in areas we should not be building in, considering future climate changes [14, 15].

Te planning system is typically also responsible for the design and layout of proposed development sites. Tis means that before any dwellings are designed, materials and technologies are selected, and construction methods are confrmed, that lot layout of vacant or underdeveloped land is done in a way that maximizes sustainability outcomes. For example, optimizing orientation can reduce the costs for design, materials, technologies, and construction methods to achieve improved performance outcomes. Conversely, if lot layout is done without considering orientation, it can negatively impact dwelling performance. Research from Australia shows that the diference between the best and worst orientations for a minimum regulated performance house in Melbourne was as much as 35% and that higher performing dwellings had less variance from worst to best orientations [16]. Research on the benefts of orientation in other locations has also found signifcant performance improvements. For example, Elnagar and Köhler [17] found thermal performance improved by 7% for a residential dwelling in Kiruna (Sweden), 15% in Stuttgart (Germany), and 22% in Palemo (Italy). In the UK, Abanda and Byers [18] modelled a house and found a 5% diference in thermal performance between the best and worst orientations and this translated this to an energy saving cost of about £900 over 30 years. Abanda and Byers [18] demonstrate that orientation is not just about reducing energy consumption but it has a wider impact on afordability and liveability, an outcome that is only likely to increase with a changing climate and increasing energy bills.

Additionally, planning systems address the question of density of housing. Arguments for density include the need to house growing populations close to amenities as well as for housing afordability outcomes. However, density should not be done at the expense of good design practices. In relation to environmental sustainability, there is disagreement across the research as to what is optimum in relation to density and diversity of dwellings. From a purely energy perspective, research has shown that detached housing is more energy intensive from dwelling operation compared to medium-higher density housing. However, this depends on what is under consideration, as higher density housing requires increased energy for things outside the dwelling such as elevators, communal lighting, and heating/cooling [19–23].

It also depends on what other considerations are included. Research undertaken in Adelaide (Australia) compared energy consumption and emissions across the life cycles of apartments within the city centre and detached homes in the suburbs. Tis research found that the total delivered energy consumption of apartment households was lower than the suburban households [24]. However, the authors found that, when looking at greenhouse gas emissions, the total per capita emissions typically exceeded those of the detached suburban households.

Te challenge in the density discussion is that when housing gets built upwards, it often results in higher embodied energy1 consumption due to the requirements of the structure and results in lower occupants/dwellings in comparison to lower density housing. Highlighting the complexity of this issue, Estiri [22], analysed more than 12,000 dwellings in the USA and found that lower density suburban households consumed 23% more energy than higher density inner city households. Again, depending on the metric, the data could be interpreted diferently with the research showing that those living in the higher density city housing had a 22.6% higher energy intensity compared to the detached suburban homes. Roberts et al. [25] found that, with apartment occupants, it was not just the diference in energy consumption, but also how and when the energy was consumed which was diferent to detached housing. Tis could have broader implications for energy generation and energy grid stability. As we move towards consuming more renewable energy we are already seeing a need to better align energy consumption with when energy is being generated [4].

In an interesting analysis of more than 73% of housing in the USA, Goldstein et al. [26] explored the carbon footprint of housing across the country. Tey calculated that if cities were to meet Paris 2050 goals, there would need to be an increase in density of 19%. In some cities, such as Boston, the required increase in density was more than 50% (increasing to an approximate 5000 residents/km2 , which the study authors say is a critical threshold for residential energy sustainability targets). Te authors also argued that densifcation has wider benefts for afordable housing, largely through the provision of more housing options in wellestablished areas.

Te design stage is also critical for the sustainability of a dwelling. In many countries around the world, like the USA, Canada, and Australia, the foor area of new detached housing has been increasing for many years, although there are signs that this may have plateaued [27]. Te

<sup>1</sup>Embodied energy is a calculation of all the energy that is used to produce a material or product, including mining, manufacture, and transport [1].

growth in foor area has not occurred equally around the world or across housing types; other jurisdictions, like the UK and Sweden, have much smaller housing [28]. Furthermore, while the average new detached dwelling size in Australia has grown in recent decades, the opposite was seen for Australian apartments with a rapid increase of small apartments entering the market and prompting some Australian states to introduce minimum design, space, and performance requirements.

Te increase in the average foor area of new dwellings has been occurring at a time of declining average occupant numbers. It has also occurred across a period of increasing shifts in consumer expectations around housing quality and inclusions. As Ellsworth-Krebs [27, p. 22] states, the trends of 'increasing house sizes and foor area per capita undoubtedly impact expectations of home comfort and aspirations for the ideal home. Just as standardization and globalization has resulted in homogenization of indoor temperatures across the globe over the past forty years, so too can increasing foor area per capita shift norms and expectations of how much space is "enough"'.

Increasing foor area has an impact on the design, quality, and performance of dwellings [29, 30]. Research in the USA found that a 1000 square foot increase in dwelling size would result in a 16% increase in energy consumption for space heating/cooling [31]. In Australia, researchers estimated that each 2% increase in average new foor area would add 1 tonne to a household's total CO2 emissions per year [32]. Although much of this growth in foor area occurred during the same time that minimum performance requirements were introduced, research has found that the growth of foor area of detached housing has largely nullifed energy efciency gains from these improve thermal performance requirements [33]. It is also not just the foor area that is an issue for sustainability, but that the growing foor area on decreasing lot sizes means there are less opportunities to optimize passive design and address wider issues such as the urban heat island efect [30].

Tere also needs to be a better match between occupant numbers and house size or number of bedrooms due to the impact on sustainability outcomes. In China, Wu et al. [34] found that removing one person from a household results in an increase of 17–23% per capita residential electricity consumption. In England, Huebner and Shipworth [35] found that if single occupant households with multiple bedrooms downsized by one bedroom, they could achieve an 8% energy efciency saving, or a 27% saving if they downsized to a one-bedroom dwelling. Te authors also note the range of benefts downsizing has beyond environmental benefts, such as social and fnancial ones like freeing up larger dwellings for growing families and releasing equity for those downsizing.

Tese benefts have not only been identifed for small occupant households; in the USA, Berrill et al. [36] found that changing 14 million dwellings from family housing to multi-family housing would reduce energy demand by up to 47% per household and reduce total urban residential energy by up to 8%. Clearly, the benefts achieved just from ensuring appropriate household and housing balance will have signifcant implications for the environment. As McKinlay et al. [30, p. 146] state

[g]overnment policies that attempt to address urban consolidation, green urbanism and housing afordability, seldom consider the dwelling size factor … Te size of a dwelling has cumulative efects for sustainability at the scale of both neighbourhood, city and country. If these sustainability goals are to be met, the dwelling scale needs addressing. It can be speculated that neoliberal government attitudes avoid intruding in the private realm of the home, however policy documents need to refect dwelling size as a fundamental aspect of sustainable housing.

Tis is echoed by Cohen [28, pp. 175–176] who writes, "the important insight is that size matters and if policymakers are serious about sufciency – especially with respect to meeting climate targets and commitments embodied by the SDGs (Sustainable Development Goals) – it is imperative to devote serious consideration to shrinking foor area".

However, Huebner and Shipworth [35] pointed out a number of challenges in achieving these outcomes, including a limited number of options for such households to downsize into. Similar arguments are put forward by Ellsworth-Krebs [27, p. 22] who says any focus on restricting increasing dwelling sizes must be done alongside ensuring that alternative housing options "provide[s] adequate occupant satisfaction in terms of privacy and personal space as this is assumed to be a part of modernization and a driver towards smaller household sizes". Jack and Ivanova [23] echo these calls, arguing policy makers must think about new ways to encourage new forms of shared living and downsizing as part of an approach to reduce residential carbon emissions. Others like Berrill et al. [36] argue that there needs to be innovation in the use of taxes and subsidies to help guide the housing industry and consumers to build the type of housing we need in the future.

#### **4.2.2 Materials, Construction, and End of Life**

Many of the environmental impacts across the life of a dwelling are well known. Tese include the life cycle impacts from the extraction of raw materials; the manufacture and use of materials for construction; dwelling maintenance and the resources consumed, such as energy and water, by the people living in the dwelling across the building's life; and the impact from end of life of the dwelling (e.g., disposal or reuse of materials). Many of these impacts are locked in at the design stage and become costly to rectify once a dwelling is built. Elements such as material use, foor area, orientation, and thermal performance levels have been found to be key parameters for determining the environmental impact of a dwelling [37].

Globally, the housing sector consumes between 30–50% of materials with the total amount predicted to increase alongside the need for more housing and the increasing average foor areas in some countries [38]. In their analysis, Marinova et al. [38] identifed that, by amount, concrete is the most signifcant material consumed within the housing sector at around 250 Gt in 2018. Other key materials include steel (12 Gt) and wood (10 Gt). It is not just the sourcing of raw materials that creates a signifcant environmental impact, but also the embodied energy required to source and manufacture the end products [1]. Te use of these materials is not universal as dwelling designs, materials, technologies, and construction methods difer around the world and change over time based on a range of factors including historical, cultural, and climate [39]. In recent years, supply chain shortages for construction materials have been emerging in diferent regions around the world, highlighting how fragile the globalized material supply chain is and how signifcant of an impact this can have on local construction costs and other outcomes.

Te impact from materials occurs through the generation of waste during construction, through-life (maintenance), and at end of life. Eforts have been made in some jurisdictions to reduce construction waste generated and increasing the amount of waste being reused or recycled. Tis is evident in the waste reduction and recycling targets and requirements being set in diferent locations around the world. It is also being driven through improved requirements in voluntary sustainable housing standards. For example, the LEED v4.1 Residential Single Family Homes rating sets out a minimum waste reduction requirement of 40–50% (depending on what option the project follows). Tis is low in comparison to international best practice for construction waste reduction and/or recycling; construction waste recycling is up over 90% in jurisdictions like Singapore [40], and is above 70% across the EU [41]. However, there is a gap between international best practice and what many jurisdictions are doing.

In terms of embodied energy, research has found that it can account for 5–35% of a typical dwelling's overall greenhouse gas emissions impact [1]. However, as we start to provide sustainable housing, this embodied energy impact could rise to 80% or more of the dwelling's greenhouse gas emissions total lifetime impact as the impact of zero carbon energy shifts where the environmental impact of a dwelling occurs [42]. To date, the focus on sustainable housing has often looked at reducing the environmental impacts during the diferent phases of a dwelling's use, but there is an increasing call to better incorporate considerations of material impact, and specifcally embodied energy, in the provision of sustainable housing. Te need to focus on materials will only grow with more improvements to building design and energy efciency, and the increasing inclusion of renewable energy technologies [42]. Tis focus of materials also needs to be considered within planetary boundaries as we are consuming many resources faster than the earth can replenish them [43].

Material choices have primarily focused on environmental impacts, but there is increasing acknowledgement that we need safe materials and to consider social implications of material choices [44]. Tis is not only from an environmental perspective but also in relation to the safety of the dwelling and those involved in the process of producing the materials. Flammable cladding is an example that has emerged in recent years as a signifcant building safety issue in countries like the UK, Dubai, and Australia. Tis cladding which goes on the outside of a dwelling has certain properties which increases fre risks, and has been responsible for rapid spread of fre in building fre events such as Grenfell Tower in the UK where more than 70 people lost their lives [44]. While the cladding in question was developed partially to improve thermal performance, it is an example of unintended consequences. Tis has resulted in increased fre risks for thousands of impacted dwellings around the world and will likely cost billions of dollars and take more than a decade to mitigate the issue [44]. Furthermore, homeowners are experiencing substantial negative impacts to their fnances and well-being [45, 46]. Similar environmental, social, and fnancial impacts were experienced during the leaky homes saga in New Zealand, leaky condos in Canada, and the global issues with asbestos and more recent materials such as engineered stone benchtops [44, 47, 48].

Recent policy developments at a global level have also moved beyond material safety on the construction site, introducing modern slavery laws that address safety across the supply chain [49]. Tis makes it clear that the stakeholders responsible for the housing provision process have a duty of care and responsibility for ensuring that social considerations are included throughout any decision making processes. Te terms "ethical sourcing" and "responsible sourcing" are used to refer to choices that housing sector stakeholders make that support organizations and suppliers that value and demonstrate ethical working practices. Some voluntary sustainable building rating tools and systems, such as LEED and Living Building Challenge, provide purchasing guides or material requirements that meet sustainability and equity standards to encourage or ensure responsible choices. However, housing policies like building codes or land use planning generally have not included any equity requirements.

#### **4.2.3 Use and Technology**

A dwelling's impact on the environment is also infuenced by how occupants are using the dwelling and what technology is (or is not) included in the dwelling's design. Te International Energy Agency found that, in 2019, the housing sector contributed 17% of global greenhouse gas emissions [37]. Tis is primarily due to the amount of fossil fuel energy required to operate dwellings. Te decisions made about the design, materials, technologies, and construction methods used can signifcantly reduce greenhouse gas emissions when they improve a dwelling's energy efciency and reduce its energy consumption.

In many developed locations around the world, heating and cooling energy requirements make up the majority of energy consumed by a dwelling [37]. Tis has been driven by a rapid uptake of mechanical heating and cooling systems in recent decades as technology has become cheaper and changing social norms have resulted in expectations for yearround thermal comfort to be maintained through narrow temperature bands [50–53]. Energy consumed for heating and cooling varies around the world, largely infuenced by climate but also by dwelling quality. Heating and cooling has been found to make up 55% of total residential energy consumption in Central and Eastern Europe, 52% in North America, 49% in Oceania, 46% in Western Europe, 40% in Latin America, 33% in South Asia, 24% in North Africa and the Middle East, and 20% in Sub-Sahara Africa [54]. We have the technology to construct housing that requires signifcantly less (or even zero) mechanical heating and cooling, such as through the thermal improvements of building envelope and making use of passive design features (e.g., the use of natural sunlight to support heating). Tis can signifcantly reduce the amount of energy a household consumes, and the generation of greenhouse gas emissions associated with it.

Some countries are also beginning to face challenges with the rapid uptake of renewable energy technologies and the use of battery storage at the individual dwelling scale. Many energy networks were not built with small-scale energy distribution in mind and they are now struggling to cope with the introduction of renewables such as solar PVs. In some jurisdictions, there are concerns around energy grid stability and, subsequently, for larger energy generators (typically fossil fuel generators). For this reason, certain locations in Australia are not allowed to instal additional residential renewable energy. While this might be rectifed with improvements to energy network infrastructure, it is problematic for several reasons including that it locks out those who were slower to add renewables. Tis is of concern for those who experience housing vulnerability, with previous research fnding that it has been the middle and higher income earners who have been the ones to take up residential solar PV while implementing these technologies presents a range of challenges for renters [55–57]. Tere are also instances where energy network providers are turning of renewable energy generation on houses for short periods of time when there is an issue with grid stability such as in South Australia in March 2021 [58]. So, even if a household incorporates sustainable technologies into their dwelling, factors outside of their control can impact how the dwelling performs and how it is used.

Te issues presented above are largely developed country issues. In many developing countries, there are still challenges around providing energy of any generation type, as well as challenges in providing other critical requirements such as safe drinking water. Te UN Sustainable Development Goals identify that, in 2020, 733 million people were without electricity connection to their dwellings, more than 2.4 billion still used inefcient and polluting cooking systems, 1.6 billion lacked safe drinking water, and 2.8 billion lacked safe sanitation. When considered alongside the fact that around 1 billion people are estimated to be living in slums or informal settlements, this highlights the depth of housing provision challenges in some jurisdictions.

# **4.3 Neighbourhood and City Scale**

#### **4.3.1 Where and How to House a Growing Population**

Since 2007, more than 50% of the world's population has lived in urban regions. Te UN predicts that, by 2050, close to 70% of the world's population will be urban [59]. Te growth in urbanization is primarily due to population growth and migration/immigration. However, regions around the world have experienced this growth diferently. In North America and Latin America and the Caribbean, more than 80% of the population lives in urban areas. Tis number is closer to 75% in Europe, just under 70% in Oceania, 50% in Asia, and just over 40% in Africa. Tese urban areas range in size, from tens of thousands to tens of millions. While most of the world is experiencing population growth, there are some regions that are experiencing decline, including Japan, South Korea, Eastern Europe, and parts of Germany.

Te pressure from population growth has forced cities to fnd ways to house their growing populations; for many cities, this means going out (expanding the urban growth boundary through suburbanization and peri-urban developments) or going up (building medium and high-rise apartments). Growing outwards to accommodate an increase number of dwellings is most common in places like USA and Australia. Tis is largely driven by a need for cheap land to build on, with the perception that it helps with housing afordability, and that building new developments is easier and cheaper than urban infll2 or urban renewal/regeneration.3 Tis has caused a loss in natural environment as areas that were forests or agricultural land are now being consumed for the construction of new housing. Tis creates issues in relation to food security, biodiversity loss, and air quality, among others.

Tere is also an increase in jurisdictions around the world that have altered the natural environment to reclaim space for construction. Examples include land reclamation in Singapore to increase the size of the island and accommodate more development, and building over waterways on the Gold Coast (Australia) and over mangrove forests in the Niger Delta (Nigeria) for urban expansion. Reclaiming land can be costly and there are several examples of where it has, or could, cause issues longer term. For example, a signifcant number of developments on the Gold Coast are now at risk from rising sea levels, and the 2021 apartment collapse in Miami (USA) highlights the safety issues around building in such areas [44].

<sup>2</sup>Urban infll refers to the development of vacant or underused parcels of land in otherwise built-up or developed areas.

<sup>3</sup>Urban renewal, or regeneration, is where an area of a city is targeted for unlocking under-utilized land and amenity. Tis may involve the redevelopment of existing buildings and infrastructure or the development of vacant land. It can often involve rezoning land, improving an area's amenity, and improving wider access.

Unfortunately, the design of urban regions in many parts of the world has largely been done in ways that are not optimized for sustainability. Te challenge is that once our built environments are constructed, there are limitations to what can be done to improve outcomes. Tis applies to the micro and macro level. For example, the way streets and blocks are developed will determine how a dwelling can engage with principles of sustainable design, quality, and performance. While there are design options that can negate some of those challenges (such as access to a certain amount of sun during winter to reduce heating needs), this can add cost and complexity to housing delivery. At a larger scale, the way we have designed our neighbourhoods also creates lock in. For example, adding public transport in the form of trains or light rail to an already established urban area can be costly and limited to existing space and infrastructure, leading to costly and suboptimal outcomes.

#### **4.3.2 Urban Climate Change**

In addition to housing a growing urban population, many cities are facing unique challenges related to climate. It is not only the changes in climate that impact housing performance, but also how climate interacts with city design. Many cities have reduced permeable land surfaces due to increasing building numbers and the associated hard infrastructure like roads and paths. With these features, we are now creating our own microclimates in cities through the urban heat island efect. Te urban heat island efect occurs when heat is trapped in our urban environments due to high amounts of heat-retaining structures such as concrete and asphalt relative to the amount of natural cooling features such as plants and open space [60]. Temperature increases of up to 15 °C have been found in urban areas due to this heat island efect [61]. Tis can be detrimental to the health and well-being of people living in these areas. In British Columbia (Canada), the 2021 heat dome event caused more than 600 heat related deaths, while the 2022 heat waves in Europe caused over 2000 deaths in Spain and Portugal [62]. Increases in temperature also mean that more energy is required for cooling. In Sydney (Australia), researchers found a 9 °C increase in summer temperatures which resulted in an additional residential energy load of 6.4% [63].

Fortunately, researchers and practitioners have identifed and tested various strategies for reducing the urban heat island efect. Tese strategies range from increased vegetation, to the use of green roofs, to improved performance through passive design and insulation [63–65]. However, in their research across 48 states in the USA, Roxon et al. [66] fnd there are some cold climatic locations where the heat island efect can help improve thermal performance and reduce energy bills. Tis also translates to positive and negative impacts on mortality, with Lowe [67] fnding that the heat island efect can increase heat related deaths by about 1.1 deaths per million people but reduce cold related deaths by about 4.0 deaths per million people. Te above research highlights that specifc heat island responses are going to depend on a range of factors.

Global climate change also impacts housing performance in urban areas. In many jurisdictions, historical climate data is used within regulations and support tools to design and build new housing. Tis means that new housing is unlikely to perform well in a future climate. However, like with the urban heat island impacts, this can have both positive and negative outcomes [68, 69]. Using future climate data, Wang et al. [70] found a mixed result for new housing performance in Australia with performance decreasing in some climate zones (e.g., Sydney, Darwin, and Alice Springs) but increasing in others (e.g., Melbourne and Hobart) with changes of up to 350% by 2100. However, even this increase was not consistent; beyond a certain increase in average temperatures, a negative performance would be seen. In other research, Chakraborty et al. [71] found that, based on likely climate change scenarios, there would be a global increase of cooling energy consumption of 15% for apartments and 37% for detached housing. If climate change is more extreme, this could increase cooling energy consumption by up to 121% for detached housing. In Canada, while energy for cooling in apartments is predicted to increase by about 40% by 2070, energy for heating is likely to decrease by 27% [68] which is similar to results for four USA cities studied by Shen [69].

What the above evidence points to is that we should be building for IPCC's mid scenarios for a future climate, with an assumed mid-range life of a dwelling. For example, if a dwelling was built in 2020 and expected to last 40 years, it should be built for a 2040 climate. Tis climate data should not just include temperature but also changes to other areas of the natural environment (such as sea level rise, fooding, and bush/forest fres), and be used to inform housing design, material and technology selection, construction methods, and use. When urban planners and other residential stakeholders are considering these things, they must consider where we are building and living.

# **4.4 State, National, and International Scale**

#### **4.4.1 The Social Challenges**

Research has demonstrated that poor quality housing can exacerbate or create poor health and well-being outcomes, and conversely, that sustainable housing can improve these outcomes. As we spend most of our time indoors (up to 90%), the design, location, quality, and sustainability of our dwellings becomes increasingly more important for health outcomes, both broadly as well as during extreme weather events [72–83]. Unsurprisingly, the research typically fnds that it is those who are already vulnerable that are impacted most by this issue.

Another social challenge is global population growth, resulting in more housing being needed. Te UN has predicted that the population will grow from 8 billion in 2022 to 10.9 billion by 2100 [84]. However, assumed continued population growth is being challenged with the UN noting that a number of countries are experiencing population declines. Others such as Bricker and Ibbitson [85] and Vollset et al. [86] argued that the evidence suggests we are already facing a more rapid reduction in population growth and that we are unlikely to reach the numbers projected by the UN. In relation to housing, a smaller population is likely to help address some of the previously identifed issues such as how and where we get materials from. However, there is still a signifcant challenge in how we improve the design, quality, and performance of existing housing and the signifcant numbers of new housing predicted to be built over the coming decades.

Additionally, policy making for a low carbon future must bring together the technical with the social. Research looking at the transition to low carbon housing requirements in the EU, UK, North America, and Australia found that the jurisdictions that had the strongest current and future housing performance requirements clearly communicated how those requirements were going to address a range of environmental and social issues (such as health and well-being, fuel poverty) and linked the outcomes of the policy to other key government policies [9, 87]. In some locations, there is a shift in the focus and language around sustainable housing, moving from one that is strictly about environmental impact (e.g., zero carbon) to include the wider social benefts (e.g., improved health through more stable and comfortable indoor air temperature). Tis is helping in broadening the benefts and appeal of sustainable housing and addressing some of the arguments put forward by those against the changes. While some people might still see improving sustainability outcomes as a "nice" to have element, it is harder for people to argue against improved health and well-being and reduced living costs!

#### **4.4.2 Governance**

Tere are also key governance challenges to delivering sustainable housing. As discussed in Chap. 2, the improvement to housing performance (or sustainability outcomes) has largely been driven by the introduction, and then revision, of performance requirements [88, 89]. However, these minimum performance regulations create tensions between policy makers, the housing construction industry, and those who argue they do not go far enough. Often when it is suggested that minimum performance requirements should be improved, and that longer term targets should aim to achieve zero or low carbon/energy outcomes, there is signifcant push back from key stakeholders who are opposed. Te housing construction industry tends to be entrenched in the ways they operate and do not like anything they perceive to impact their productivity or ability to make money. Tis then turns the discussion into a political point scoring and support exercise and ignores why the discussion is required in the frst place. Te revoking of the Code for Sustainable Homes in the UK is an example where diferent politics played out to negatively impact the push towards more sustainable housing [90]. A change in government led to a change in priorities and, ultimately, a softening of sustainable housing performance requirements and the long-term policy pathway.

An issue which has had increasing attention in recent years is that, despite the use of minimum performance standards, there is signifcant evidence of a performance gap between what those standards require and what is delivered as the end product, especially with new construction [91–94]. Tis is problematic for several reasons. Firstly, consumers are not getting what they are entitled to in relation to minimum performance. Secondly, it is locking occupants and owners into poorer performance and higher living costs. Tirdly, it helps perpetuate a housing construction industry that already struggles with issues of quality and accountability in many parts of the world.

Researchers have found that buildings can consume up to 250% more energy than predicted in design, although the gap tends to be in the 10–30% range across larger data sets [91]. A study of a housing development in Italy found that there was a gap of 44% between predicted and actual performance but that, by updating various assumptions in the design model (such as the weather fle, use profle, and heating, ventilation, and air conditioning features), they were able to close this gap to 7% [94]. Stellberg [95] translated the broader performance-design gap into an economic energy waste number by analysing studies from the USA that found there was a signifcant issue with high non-compliance against elements of building codes in most states, and as high as 100% in some jurisdictions. Tis represented reduced economic and environmental benefts of the codes by up to US\$175 million a year (for both residential and commercial buildings), demonstrating signifcant fnancial waste.

One of the ongoing challenges with addressing housing performance through policy is that policy has historically only been applicable to new construction which only make up a small percentage of the overall building stock. For example, in Australia, new dwellings only make up approximately 1–2% of housing each year. Around the world, various reports highlight that the majority of the housing stock in 2050 has already been built [96]. If we are to deliver sustainable housing, we need to address the dwellings that already exist. Te International Energy Agency estimates that up to 2% of the existing building stock undergoes energy renovations per year and that these retrofts lead to energy intensity reductions of up to 15% [97]. To meet future sustainability targets, there is a need to improve this both in terms of number of retrofts undertaken and the improvement in energy reductions. Minimum performance standards addressing existing dwellings are comparatively recent and not yet a requirement in all of the countries that have requirements for new housing.

As regulation implementation varies around the world, it is problematic to rely on regulations in their current form to improve sustainable housing outcomes. Some jurisdictions (like Australia) aim to set a nationally consistent approach, which often contains some subtle variances for diferent climate zones. Other jurisdictions (such as the USA, and the EU to some degree) have a more fragmented approach where the introduction or improvement of performance regulations is left to state or local governments to implement [9, 98]. Tere are arguments for and against both ways of delivering these regulations. On the one hand, a nationally consistent approach allows the housing construction industry to have more certainty when working across diferent locations and attempts to deliver a more collaborative approach to improving outcomes. Te downside is, as Australia found out, that if you require the consensus of all stakeholders to lift minimum requirements, it can take just one State or stakeholder to delay the process or create weaker outcomes. When governments are responsible for developing and setting minimum requirements, it can lead to inconsistency in relation to what the targets and requirements are. However, this responsibility also allows the jurisdictions who want to lead or innovate housing to do so. Tis is what is happening in California, which has a long history of leading in the sustainable housing regulation space [99]. Where the federal or national government does not have authority to set performance requirements, these governments tend to use other levers to try and drive change including through the provision of rebates, subsidies, training, and other support [100].

Tere is also an issue of split incentives for rental housing where those responsible for paying energy bills (the tenant) are not the same as those who make capital investment decisions (the dwelling owner). A range of policy, economic, and sustainable housing researchers have found some landlords are unwilling to spend money on sustainability or quality upgrades. Te tenant does not have control over changes that can reduce living costs, improve health and well-being, and increase the thermal comfortable of their housing [101–103]. Some jurisdictions have developed policies to try to overcome this split incentive. In the UK, the "How to rent a safe home" guidance states that landlords must 'supply adequate heating in proper working order', and that 'a cold home is one that cannot be maintained at a temperature between 18°C to 21°C at a reasonable cost to the occupier' [104]. In New Zealand, under the "Healthy Homes Standards", 'the landlord must provide at least one fxed (not portable) heater that can directly heat the living room to at least 18°C' [105].

### **4.5 A Market Unwilling to Change**

Te broader housing market contains several structural challenges that prevent sustainable housing from being provided in larger numbers. Over recent decades, housing afordability issues have been growing more signifcant in many parts of the world [106–108]. Te discussion on housing afordability has focused largely on the cost of purchase (ability to borrow and then service a home loan) or payment of regular rent [109]. Several factors have combined to cause housing prices (both purchase and rent) to rapidly increase in many cities around the world, a rise that has typically outpaced increases in wages. Tis has meant that people require an increasingly large deposit to purchase a property and that loan amounts are growing. It is now increasingly harder for aspiring frst-time homeowners to enter the market without sufcient fnancial resources as well as impacting on those already in the market [110]. Tis also pushes lower-and middle income homeowners further out from the city centre in the search of "afordable housing" [109]. In the rental sector, increasing rental costs have meant that those who are renting, but want to own a home, are taking even longer to save for a down payment, and/or impacting where they can aford to rent.

Tis is leading to an increase in the number of people living at home longer or staying in other types of shared housing to save money or because it is all they can aford and this is reshaping a range of wider social and fnancial norms. For example, research from the UK shows that the increasing cost of housing has a signifcant impact on the social and fnancial well-being of individuals and society [111]. Te research found that 21% of 18–44-year-olds without children were delaying starting a family due to the lack of afordable housing, and an increasing number of young adults were living with their parents longer which was negatively impacting that relationship. More than a quarter of people had made trade-ofs to help pay for housing costs (such as reducing spending on food) and almost a quarter of people were continuing to live with a partner, or knew someone who was, because it was not afordable for them to live apart. Tere is also an increasing body of evidence emerging that relates to the negative health and well-being outcomes associated with unafordable or precarious housing [112, 113].

Sustainable housing researchers and advocates have started to engage with afordable housing debates, arguing that sustainable housing is important for improving afordability outcomes [9, 114]. Afordable housing researchers and advocates have now started to reconcile that housing costs are more than just capital costs and are starting to call for inclusion of costs of location, transport, and energy within afordable housing discussions. As Hafner and Hulse [109, pp., 72, 73] states:

*Explicating and measuring housing afordability inevitably involves norms about what is considered acceptable and what is not. Establishing norms for afordable, decent and adequate housing ideally must recognize the bundle of attributes that housing provides which include quality, security and location in relation to jobs, transport, facilities and services, with the latter having become increasingly important in the 2000s at least in large metropolitan areas. Households who hold diferent norms from societal/political norms may trade of some other essential consumption items to reach these housing norms or trade-of key dimensions of housing to ensure essential consumption to some degree. But there is a limit to the extent to which lower-income households can do this.*

Unfortunately, the broader housing market in many countries tends to focus on things that are perceived to increase the re-sale value of a dwelling. Elements such as location (close to amenity, places of work/study/ schools, and prestige of area), number of bedrooms (and bathrooms), and what the kitchen benchtops are made of (e.g., granite) are typically the things that people are looking for [115]. While no doubt some of these things have practical benefts, some make little diference to the liveability or sustainability of a home. As a global society, we are preconditioned to want more and to "keep up with the Joneses". You only have to watch a few episodes from any of the new home or renovation TV shows to see the types of things that are being put forward as desirable. It was not so long ago that a family home might only have one bathroom [39], but these shows have many examples of people turning up their noses at ensuite bathrooms with 'only' one vanity.

Key stakeholders in the housing construction industry who are resistant to changes often perpetuated the idea that sustainability elements add cost to a dwelling. Te argument often made is that housing is becoming increasingly unafordable to a greater percentage of the population and that we must not do anything that adds additional costs. However, this argument has a number of faws, including that we can deliver improved sustainability of housing for little or no additional costs as costs for sustainability elements have fallen signifcantly over the past decade [8, 9, 116–118].

Another challenge remains on how to engage the existing housing regime to embrace the requirements for improved sustainability. Research from around the world has consistently found signifcant tensions between the housing construction industry and regulators, and to a lesser extent consumers, as to who exactly should be responsible for housing performance [90, 119–124]. Tis resistance to change means that it is a difcult process to create broader structural changes required to deliver more sustainable housing.

# **4.6 The Complexity of Housing**

So, what do the above challenges tell us? Te role of governance is central to many of the challenges. To date, the introduction and use (or lack thereof) of policy mechanisms has been a key driver of progress towards improved housing performance. However, it is also acting as one of the key challenges that are hindering progress. Research from around the world has shown that the housing construction industry is often resistant to any type of change placed onto them via regulations, and there is an increasing desire to have partisan support for policy changes (or at least a package of support put in place to help with any transition to the new requirements). Te current practices of much of the housing construction industry, who are intent on trying to maintain business-as-usual approaches, make it challenging for those niche actors who want to innovate and push boundaries. It does not help that building codes and planning systems around the world often do not allow for innovation.

As touched on above, any changes to design, material, and technology use, and construction methods or improvements to performance are seen as adding red tape, time, or costs to a project, and that this is pushed onto clients in the form of additional costs. In the housing sector where housing afordability is a global issue, anything that is perceived to add cost is a challenging political and public sell, even when there is limited evidence to support such claims. Te narrative around the idea of cost and housing performance needs to shift from one of capital costs to throughlife costs. Te costs to live in housing can be substantial, not just from the operation of the home in relation to utility bills, maintenance, and impact on health and well-being but also the wider costs associated with location such as transport costs. Many new "afordable" houses get built in urban growth areas at the fringes of cities. Tis has a whole range of implications for liveability and afordability.

Tere are an increasing number of examples from around the world that have demonstrated that key proponents in the housing construction industry often overstate their own analyses, with costs and benefts more accurately aligning with government analyses [125]. Te housing construction industry is more likely to innovate when asked to change which has resulted in any costs for compliance or performance changes rapidly falling away through improved design, material and technology selection, and construction methods. For example, minimum building code requirements changed almost overnight in Australia after the Black Saturday bushfres in 2009 where more than 2000 houses were destroyed and 173 people died. Te building codes were strengthened for new housing in bush fre zones to require houses to be better protected against fres. While there were some concerns around this adding cost, houses have continued to be built to those higher standards. In the UK, analysis during the Code for Sustainable Homes found that costs to deliver zero carbon homes fell by more than 8% across four years, and that this was for a standard that was not yet mandatory so costs were expected to continue to fall [125]. Others have also predicted cost reductions around the world as more low or zero carbon houses enter the market and construction industries implement more efciencies and learnings around the design, materials, technologies, and construction industries [126, 127].

While setting regulation is one thing, ensuring compliance is another. As touched on earlier, there has been an ongoing issue of actual performance not meeting building code requirements [91, 93, 94]. Tis lack of compliance is enabled by a lax system of checks and balances in many countries. Tis is not just in relation to sustainable housing performance, but it has also been seen in recent housing crises around fammable cladding (e.g., UK, Dubai, Australia), leaky condo crisis (Canada), and the leaky homes crisis (New Zealand) [44, 45, 47].

Another key consideration is the way we design and select materials, technologies and construction methods for our dwellings has signifcant implications for how occupants can use them, and in turn how sustainable, usable, and afordable they are. Also important is that these impacts go beyond the individual dwelling. Tere is a complex relationship between the design and use of our dwellings and how they have been shaped by hundreds of years of development and innovation. Te design, use, and challenges of housing around the world have shifted over time. Tere is probably no better illustration of this than Bill Bryson's *At Home* book [39]. Bryson explores how some things we now take for granted in our housing (such as mechanical heating and cooling) are relatively recent innovations, and that housing continues to both infuence the occupants as well as be infuenced by them.4 While Bryson's book does not directly focus on sustainable housing, some of the elements the book discusses are elements that we have seen contribute to sustainable housing (e.g., natural ventilation).

<sup>4</sup> Indeed the shift in the ways we have changed heating and cooling practices has been a focus of various researchers [50].

Furthermore, the history of how our housing has developed cannot be considered in isolation from how our cities have developed. However, much of the focus of sustainable housing and sustainable cities from policy makers often looks at the present moment, without due consideration of how things have changed over time, or could change over the future. Tis often results in band aid solutions which are reactive to the situation rather than taking a wider consideration of the challenges and potential solutions. By this, we mean that governments have continued with business-as-usual approaches while paying lip service to sustainability or not exploring the deeper structures of what is happening and why. For example, as cities have expanded, people have become increasingly reliant on the car to get around. Tis is often because public transport is inadequate or is put into communities after they have been built and people have already established their transport practices. Te solution to trying to improve mobility is often to build more roads and add more lanes to existing roads, often at great expense. While this might provide a shortterm solution (although it rarely does), it does not address the question of why people drive. Providing work, recreation, and other amenities closer to homes (or providing homes closer to those amenities as advocated in transit-orientated development) will have a greater impact on transportation in cities than adding more roads [128, 129]. However, there are locations that deliver public transport and other non-car travel options (e.g., cycling, walking) in a much better way. We return to the need to challenge how we think about housing, and solutions for sustainable housing, in the later chapters of the book.

#### **4.7 Conclusion**

In this chapter, we have explored several historic, current, and future challenges that are contributing to holding back the provision of sustainable housing. While not an exhaustive list, the chapter highlights the range of challenges across diferent domains (e.g., technical, fnancial, knowledge), the way some of these challenges play out at diferent scales, and how they are impacted, and how they impact diferent stakeholders. We need to understand these common challenges, as well as location-specifc challenges, if we are going to be able to provide a low carbon future. Many of these challenges are deeply complex and have been entrenched in the ways we have provided housing for decades; addressing these challenges will not be straight forward. As we will discuss in Chap. 5, we have potential transitions frameworks we can draw upon for guiding the sustainable housing transition.

# **References**


*Slavery Act: An intra-industry initiative against modern slavery.* Business Strategy & Development, 2021. **4**(3): p. 279–293.


*asphalt concrete.* Journal of Environmental Management, 2017. **197**: p. 522–538.


**Open Access** Tis chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence and indicate if changes were made.

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# **5**

# **Providing Sustainable Housing through Sustainability Transitions**

## **5.1 Introduction**

Across the previous chapters, we discussed the current provision of housing and the need to transition to a sustainable housing future. We explored the benefts of sustainable housing, not just in terms of playing a critical role in achieving a low carbon future by 2050, but also the wider social and household benefts sustainable housing could provide such as reducing living costs and improving health and wellbeing outcomes. Tis was followed by a discussion on how we have been improving design, quality, and performance requirements of new and existing housing, largely guided by regulations. Despite some progress, we are now at a critical juncture. Te decisions made over the coming years will have signifcant implications for decades to come. However, we have argued there are a range of policy and market failures and other contemporary challenges that need to be addressed in order to provide a sustainable housing future.

In this chapter, we explore the concept of sustainability transitions and how it ofers a framework to change some of the deep structural elements and embeddedness within the current housing regime. Much of the focus in improving the design, quality, and performance of housing has resulted in minor tweaks rather than the more signifcant changes required to provide sustainable housing at the scale and rate required for a low carbon future. We begin this chapter with an overview of sustainability transitions theory and research, including exploring where sustainability transitions occur. Following this, we note emerging sustainable housing and transitions research and identify several important socio-technical dimensions for change which will be discussed in more detail in Chaps. 6 and 7.

## **5.2 Sustainability Transitions**

Although technological innovation and ecological modernization1 remain important for environmental outcomes, wider approaches to innovation are being argued for as a result of shifts in understanding and urgency to addressing issues such as climate change and the need for a transition to a low carbon future [1–4]. Te feld of sustainability transitions focuses on the trajectory of change towards sustainability and seeks to uncover the origins, patterns, and mechanisms that drive these transitions. Sustainability transitions theories build on an ecological modernization framing by requiring innovation while also questioning the need for technology by advocating for social considerations, environmental outcomes, and governance as well as generating deep structural change in order to achieve a transition to a low carbon future [5–7]. Sustainability transitions are co-evolutionary and involve a broad range of actors whereby innovations related to sustainability are adopted more broadly [7–10].

In this context, a sustainability transition is a process of structural, non-linear systems change in dominant practices (routines, behaviour, action), structures (institutions, economy, infrastructure), and cultures (shared values, paradigms, worldviews) from one state, stage, subject, or place to another [8, 10]. Such a transition typically takes place over a period of decades, although more recently there has been a focus on

<sup>1</sup>Ecological modernization is a technology-based approach to environmental policy and sustainability outcomes. It is often associated with efciency-based initiatives.

trying to manage and accelerate these transitions given the urgency due to climate change and other social drivers [11–13].

Te feld of sustainability transitions emerged in the 1990s as a response to short-term policy making around the world. Its origins are in science and technology studies, complex systems analysis, and governance, but many more themes have since emerged. Te early theory, policy, and practical applications of sustainability transitions emerged from the Netherlands, but other countries have embraced sustainability transitions research and/or policy development including the UK, Austria, Belgium, Finland, USA, Mexico, Spain, and Australia [1, 14, 15].

Tere are three core beliefs that diferentiate the feld of sustainability transitions from sustainability science or development:


Te systemic fght picture is where one or more alternative systems emerge to replace or transform a dominant system, leading to a better system overall. Tis concept is presented through the multi-level perspective (MLP), where transitions are conceived as the interference of processes at three levels: 'innovation (niche experiments), structure (the regime), and long-term, exogenous trends (the landscape)' [10, p. 4]. Te MLP is a framework to understand socio-technical confgurations and the processes by which niches displace existing dominant or mainstream technologies [7, 16]. Te MLP is divided into three levels that form a nested hierarchy (see Fig. 5.1). Tis nested hierarchy demonstrates that regimes are embedded within socio-technical landscapes, and niches within regimes. Landscapes infuence change both on niches and regimes; in return, niches (may) change the regimes and a new regime (may) change the landscape in the longer term. One of the strengths of the MLP is that transitions are viewed as non-linear processes [17].

Niches are generally thought of as protected spaces that are signifcantly diferent alternatives to the existing technological regime, where rules, behaviours, practices, and wider social elements can develop without typical market, competition, and innovation pressures [18, 19].

**Fig. 5.1** The MLP and interactions between the three nested hierarchical levels [adapted from 7]

Strategic niche management [20–22] focuses on creating protective spaces for niches. Tis protection provides learning opportunities, creates more robust innovations, and allows for new networks to develop [20, 23]. Tis can help to address barriers including technological factors (such as a new technology not ftting into existing systems), a lack of support for development within government policy, and market challenges (such as high costs for consumers). To create protected spaces for niches, transitions researchers have identifed the importance of shielding, nurturing, and empowering niches [23, 24].

Te multi-phase concept or the s-curve (Fig. 5.2) represents the ideal transition: a transition where the system can adjust itself to changing internal and external dynamics [10]. Te s-curve is useful for illustrating historical change, where the speed and acceleration of the transition helps to explain the trajectory of the change. While there are an increasing number of current transitions case studies, most empirical analyses that have informed the development of transitions theory are based upon historical case studies, including sailing ship to steam ship [7], coal to gas energy [25], modernization of Dutch agriculture [26], and industrialized

**Fig. 5.2** S-curve development across time

to sustainable agriculture in Switzerland [27]. Conceptually, four diferent phases of transition have been distinguished [8]:


Persistent problems are complex, uncertain, and hard to manage. Te feld of sustainability transitions is normative, as it believes in fnding solutions to create a more sustainable future. Tese solutions should come from a place of co-design and learning [10], something that is more explicit in transition management and emerging theories that incorporate politics and power. Transitions management is a theoretical framework and a practical, collaborative process to support those that want to afect positive change towards a more sustainable future. Te transitions management framework assesses how societal actors deal with complex societal issues at diferent levels but consequently, it can also be used to develop and implement strategies to infuence these 'natural' governance processes [28, p. 168]. Transitions management can be applied to larger systems, as well as subsystems and specifc projects. By 'bringing together frontrunners from policy, science, business, and society to develop shared understandings of complex transition challenges; [transitions management] develop[s] collective transitions visions and strategies; and experimentally implementing strategic social innovations' [29, p. 14]. Scholars have identifed four types of governance activities that are relevant for sustainability transitions [30]:


Within the feld of sustainability transitions, the transformation of a regime is typically the result of 'a particular power struggle between the current regime, upcoming niches and landscape pressures' [31, p. 545]. Researchers have been focusing on understanding the role of power in transitions, identifying who has the power (and who does not), and exploring if and how power dynamics can be identifed during a transition [32–38]. Given our previous discussions around the housing construction industry and the attempts to improve outcomes through governance, power has been an ongoing challenge within the push for sustainable housing.

Despite the work on power within transitions, there has been a delayed but growing focus around ethics and justice in transitions [39–41]. Tis has emerged from the need to ensure that sustainability transitions are "just" and do not leave people behind, especially those people who are most vulnerable. Researchers have been exploring how ethics and justice considerations can not only help identify problems but also help shape and guide solutions and wider transitions processes [13, 40, 42–44]. Tis includes exploring the transitions dynamics that create, embed, exacerbate, or reduce issues with ethics implications like poverty, inequality, and access [13]. Ethics and justice in transitions have been applied across diferent jurisdictions, scales, and industry sectors, including mobility [44], energy [45, 46], and cities [47]. In this book, we will consider ethics and justice within housing transitions which has not yet received much attention.

#### **5.3 Where Do Transitions Occur?**

For a long time, considerations of place and scale were often overlooked in transitions theory. While it suited case study analysis to ignore these elements, contemporary transitions have increasingly been occurring beyond traditional geographic boundaries, especially as we face global environmental (and other) challenges where fxed boundaries no longer apply. Transitions researchers have become more interested in the role of place and scale and exploring things such as why a transition may occur in one place and not another, why transitions develop diferently depending on the location, and what the importance of and implications are for spatial scales for the transitions process [48]. More explicit acknowledgement of place can support refection and theoretical advancement as theories from transitions studies are used in diferent parts of the world [49]. Place and scale are particularly important for sustainable housing given that the construction of housing is increasingly reliant on global supply chains and involves the complexity of not only improving outcomes for new housing but also for existing housing within established environments. Tis places a sustainable housing transition at both the global and local scales.

In a review of geography and transitions, Hansen and Coenen [48] highlighted the importance of cities and urban regions within transitions research. Cities, and the municipal networks they belong to, play an increasingly vital role in climate change action [50–52]. Cities are also viewed as places of experimentation [53], and transitions scholars are now investigating urban experiments and living labs (conceptually and empirically) as processes and pathways to connect place-base experiments to systemic change [54–56]. Living labs ofer a forum for innovation to develop new products, systems, services, or processes through co-creation to explore and evaluate new ideas in complex and real-world contexts [57], contrasting with the more deliberative "innovation spaces" approach of strategic niche management. In urban living labs, society becomes the laboratory rather than the technology or businesses that produce or adopt it. Urban living labs create the place where actors and organizations test new things to improve and re-shape systems and, most importantly, learn from their successes and failures as they go [58].

Transitions occur within and across many socio-technical systems, domains, and sectors, including energy, water, food and agriculture, fnance, buildings, and transportation. Many of these sectors have experienced major shifts or transitions and are likely to do so again in the future [59]. Sector-focused transitions research tends to study past or ongoing transitions and the potential for (or barriers to) future transitions, or actively tries to facilitate transitions. Studying a specifc sector provides researchers with boundaries to investigate complex problems, much like geographic scale or location. Sectors are comprised of networks of actors, which include be individuals, frms, and other organizations, institutions, which represent norms, regulations, standards of good practice, and material artefacts and knowledge [34].

One of the initial sectors that received signifcant attention within the sustainability transitions feld was energy. Tis focus was largely on how previous and ongoing energy transitions occurred, as well opportunities for transitions from fossil fuel energy systems to renewable energy systems [15, 60–67]. Energy transitions research has explored issues around politics, policies, markets, actors, power, and lock-in of existing fossil fuel systems. In more recent years, the focus has started to shift from energy as one large isolated domain to acknowledge the smaller scales and decentralized nature of energy systems and that energy overlaps across domains such as the built environment and housing. As discussed in earlier chapters, for the past few decades, the focus of improving housing performance from an environmental perspective has really been on improving energy efciency, reducing energy consumption, and (more recently) fnding opportunities to shift away from fossil fuel to renewables.

Within the realm of energy transitions, there has been an increasing focus on the role of households and renewables as part of the broader sustainability transition. Bergman and Eyre [68] explored the role that small-scale renewable energy generation (microgeneration) could play in a transition to a low carbon future in the UK. What they found was that this shift in energy generation technologies had the potential to facilitate deep structural changes relating to energy consumption. For example, people who generate their own energy would go from being energy consumers to "energy citizens" that consume and produce energy, giving them new responsibilities, levels of awareness, and agency. Tis would be a signifcant departure from the existing energy regime and has a role to play in a transition to sustainable housing. Tis is already playing out around the world. For example, more than one third of dwellings in Australia now have solar PV on their roofs and this is fundamentally shifting the discussions around energy generation and what it means for sustainable housing [69].

Tere has also been a focus on the energy consumed to power the built environment. Tis includes the need to shift from fossil fuel energy to more sustainable energy alternatives (such as electric vehicles and bicycles charged by renewable energy technology) and the provision of more opportunities to move away from individual cars to improved active and public transport. Where a dwelling is built and how well it is connected to local amenities and services is important, but much of the focus on sustainability transitions for transportation has focused more on how transport can be made more sustainable. Discussions on transportation transitions have generally overlooked considerations of why people need to travel and how the provision of ideas like the 15- or 20-minute neighbourhood should be part of any solutions.

Across transitions studies, frms, businesses, and other industry actors are increasingly being recognized as playing important roles in sustainability transitions [13]. Tese institutions and actors are often part of the regime,2 those who shape and infuence societal elements such as policies, regulations, technologies, user practices, and cultural meanings. Transitions scholars have typically been interested in how these industries and businesses contribute to or slow down transitions [13]. New directions in this area of research include destabilization and decline of industries, change across industries such as the impact of information and communications technology, the role of fnance capital and regulation, institutional dynamics, and business model innovation [13, 70, 71]. Businesses and industries also ofer interesting perspectives for transitions research because they intersect with other areas of study, including politics, social movements, and geography [13, 70].

Another avenue of research commanding increasing attention is the need to better conceptualize diferent actors and their changing roles and interactions within sustainability transitions [38, 72–75]. Transitions scholars have emphasized that actors in supporting roles are important to the success of innovations and transitions processes [58, 76]. Identifed as intermediaries and champions, these are individuals that create spaces for innovations to occur, facilitate innovation processes, and act as knowledge brokers and networkers [76]. Users are another set of actors that play an important role in transitions processes. Users are active players in these processes, championing change [76] and contributing to new innovations in technologies, products, and practices [77]. In addition to being consumers, users can also be voters within democratic institutions and participants in political and social movements [78]. Lastly, niche actors, those who develop or work on innovations, 'create a starting point for systemic change' by working within or against dominant systems [74, p. 6]; niche actors try to 'convince the wider social world that the rules of the game need to be changed' [23, p. 1033].

<sup>2</sup>A regime is defned as the articulation of the paradigm sum of current practices, beliefs, methods, technologies, behaviours, routines, and rules for societal functions [16].

#### **5.4 Sustainable Housing Transitions**

Recent years have seen an increasing focus on housing within sustainability transitions [6, 11, 12, 76, 77, 79–94]. Core to this research has been the recognition that incremental improvements or changes to housing quality and performance requirements are not sufcient for providing the type of housing required for a low carbon future. In response to market failures, researchers exploring housing through a transitions lens have argued that, in order to provide the housing we need both now and in the future, we need more than just a technical solution and will require deep structural changes to the way housing is provided and used [95].

An increasing number of researchers have attempted to explore these deep structural changes and impacts for sustainable housing. For example, research by Bergman et al. [6, 96] explored sustainable housing pathways in the UK with a focus on identifying deep structural changes that are critical to provide a sustainable housing transition. Te researchers found that, if deep structural changes are to be achieved, signifcant pressure must be placed on the existing regime not only by niche actors but also by landscape elements (e.g., climate change). Further, they identifed that signifcant support must be given to niche actors to allow them to develop and challenge the existing regime (protected space); the emergence of urban living labs (as discussed above) has been an attempt to try and facilitate this. Bergman et al. [6, 96] concluded that it is possible to achieve deep structural change on a pathway to sustainable low carbon housing, but that it will require radical changes to current housing and energy performance regulations.

In recent years, scholarship has further explored the role of policy and regulations within the housing space through a transitions lens including our own previous work [62, 79, 85, 91, 97]. Tambach et al. [62] concluded that several critical elements are missing from the current range of policies in the Netherlands hindering a transition to a sustainable housing future. Tese included a lack of a long-term policy agenda (and, in turn, short and medium-term goals and visions), a lack of upskilling industry in preparation for changes, and a requirement for fnancial reconfguration (e.g., niche protection through rebates and low interest home loans). Edmondson et al. [91] adds that sustainable housing policies must include mechanisms to produce positive feedback early, that there must be adequate support and resources provided, and that clarity of information is critical. Without these elements, the authors argue that policies, even if they are well intentioned, can lead to uncertainty and inertia. In our own research, we have looked at the role of mandatory and voluntary policy approaches for driving a sustainable housing transition and found that voluntary approaches (e.g., non-mandatory sustainability rating tools) are critical for driving the top end of the market while mandatory requirements are important for lifting the bottom of the market [85]. However, Kivimaa and Martiskainen [97] analysis of sustainable housing in the UK demonstrates that the development of policies or support does not guarantee outcomes. In their analysis, they explored how, after a long period of pre-development followed by an initial take-of of sustainable housing policy, the policy commitments underwent a period of backtracking driven by the government watering down broader climate ambitions and rescinding a range of policy and support packages.

Beyond the policy focus, work by Smith [5, 82] has been important for understanding the context and practices of sustainable housing as a niche in comparison to the wider housing regime. Table 5.1 compares the clear socio-technical diferences across the two housing types. As refected by Smith, sustainable housing in the early part of the century was characterized through small scale, bespoke housing with a strong and connected community committed to an active sustainability lifestyle.

As discussed in earlier chapters, ideas and practical outcomes of sustainable housing have shifted in recent years compared to the characterization put forward by Smith. For example, no longer is sustainable housing only being provided as bespoke single dwellings but is starting to be provided at scale. Te sustainable housing transition has also shifted from being more focused on new housing [5, 82, 98] to how to retroft existing housing [12, 92, 99]. It is also broadening to consider connection and engagement with other sectors such as energy, transport, and justice. Tis means questions are being asked by researchers as to whether sustainable housing is (still) a niche or if it is something else.


**Table 5.1** Contrasting socio-technical practices in sustainable housing niche and mainstream housing regime [adapted from 82, 86]

More recent research has also challenged the previous passive consideration of the household within transitions research and has called for greater focus on the role households will play in the transition [83, 100]. For example, Greene [101] writes about how household consumption practices are both shaped by, and shape, housing performance and outcomes. Tere has been a lack of consideration of this within the conceptualization and provision of sustainable housing to date. Further, Martiskainen et al. [90] explored the development of residential heat pumps from a niche to challenging the regime in Finland and the UK. Te research drew upon the diferent users identifed by Schot et al. [77]: user-producers, user-legitimators, user-intermediaries, and user-citizens. Martiskainen et al. [90] found that the role of users was important for shaping the heat pump transition in Finland and achieving an outcome where heat pumps were normalized. Conversely, in the UK, users had not been as actively involved and uptake of heat pumps in the UK was still considered a developing niche. Te UK case also highlighted the challenge of the powerful regime with reports that government support for heat pumps was tempered due to concerns around push back from the powerful "gas mafa". Tis case also highlighted that the wider sociofnancial contexts were important (e.g., the cost of gas heating in the UK was still quite cheap at the time and it had a strong regime).

What is clear within the emerging sustainable housing transitions research is that there is an increased focus on housing and how it can transition to a sustainable future. Further, as progress is made around the world to lift housing quality and performance outcomes, this continues to raise the bar for what a sustainable housing transition looks like and what could, or should, be looked at within this space in terms of mechanisms or approaches to provide a sustainable housing outcome. In our early work [86], we argued that the rapid uptake and normalizing of residential solar PV around the world has shifted the discussion around energy consumption and generation in housing, and refected on what that means for what the benchmark was for sustainable housing. While the rapid uptake of solar PV in Australia was likely more infuenced by rising energy prices than sustainable housing or wider sustainability considerations, it has led to signifcant outcomes for more than a third of the population. Tis means that the benchmark for sustainable housing is diferent to what it was a decade ago and will likely be diferent in another decade as battery storage and other technologies/materials enter the market and become cost efcient.

#### **5.5 Conclusion**

We feel that the sustainable housing research, both broadly and within the transitions space, has not taken the opportunity to question what housing is and where it is going. Te housing market in many developed countries continues to provide very typical housing typologies without questioning if that really is meeting consumer needs not only now but also into a changing future. For example, in countries like Australia and the USA there has been a preference for increasing house sizes which has implications for sustainability and the cost of living. Small houses have had a stigma attached to them, but (as discussed in Chap. 7) the tiny housing and small space movement is showing what can be done with small spaces when careful design and construction is applied. We believe that researchers, policy makers, the building industry, and housing consumers must take the opportunity to critically question not only the quality and performance of housing, but also if it is meeting our needs. Tis questioning needs to occur at the same time as challenging the deep structural changes of the existing regime.

Sustainability transitions ofer researchers, policy makers, and practitioners a framework or lens which may be able to address the limitations of current policy and market thinking. Of particular interest to transitions researchers over recent years has been how to enable and manage such transitions. While there are critiques over if a sustainability transition can be 'managed' there is increasing evidence that the more we can understand about current or potential transitions, the better placed we will be to help guide transitions as they emerge.

Sustainable housing has received increasing focus within the sustainability transitions literature and by policy makers looking at deeper structural changes. Te work by Smith [5, 82] and others helped map out the existing housing regime as well as the emergence of the sustainable housing niche. However, developments in the sustainable housing space in recent years means sustainable housing has moved beyond a niche and fnds itself at the core intersection of a range of sector, scale, and industry development. Drawing upon the recent sustainable housing transitions research we have identifed a number of important socio-technical dimensions which we feel will play an important role in providing that sustainable housing future. We discuss these in more detail in Chap. 6.

# **References**


#### **5 Providing Sustainable Housing through Sustainability…**

*of system disruption in Germany and the United Kingdom.* Energy Research & Social Science, 2020. **59**: p. 101287.


**Open Access** Tis chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence and indicate if changes were made.

Te images or other third party material in this chapter are included in the chapter's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

# **6**

# **Socio-Technical Dimensions for a Sustainable Housing Transition**

## **6.1 Introduction**

In the previous chapters, we have made the case for why we need to urgently transition to a sustainable housing future for new and existing housing. Tis transition is needed both as part of the wider transition to a low carbon future and for the benefts such housing will provide occupants such as improving afordability and health and well-being outcomes. Our current way of providing housing has failed to sufciently improve the quality and performance of housing in many regions of the world. As such, improving these outcomes has relied on setting and increasing minimum housing performance regulations. However, while there have been improvements in recent decades, the speed at which we need to transition to a sustainable housing future means more must be done to address a range of market failures. Every year we delay making the required changes, we continue to lock an increasing number of households into poor quality and performing housing which will be costly and (potentially) challenging to retroft at a later stage. In the previous chapter, we explored the concept of sustainability transitions and of how this may ofer us a frame to change deep structural elements and embeddedness within our current housing regime. We argued that this framing is required if we are to move beyond incremental sustainability improvements and unlock more signifcant change.

In this chapter, we explore key socio-technical dimensions that we have identifed through the wider literature and our own sustainable housing research which we feel are important to address if a transition to sustainable housing is to be achieved. Tese dimensions build upon the dimensions identifed by Smith [1] but have been updated and added to as informed by more recent research and developments across the housing and sustainable housing space [2]. Table 6.1 outlines and defnes the ten socio-technical dimensions we cover in this chapter.



Tis chapter explores each dimension in turn by providing a defnition, overview of how the current housing regime engages with it and how sustainable housing ofers a diferent approach. We also provide a short example of how this is being provided or considered in practice. In Chap. 7, we explore these dimensions further through in-depth case studies.

#### **6.2 Guiding Principles**

For this book, we defne guiding principles as the embedded moral values that establish a framework for expected behaviour, practices, and decision making. As discussed in earlier chapters, the existing housing regime in many regions of the world is dominated by entrenched guiding principles located within the frame of neo-classical markets and by stakeholders who use this approach to design, construct, and maintain housing in a certain way—low quality and low cost—with little consideration for the environment and follow the minimum building code and local planning system requirements [3–7]. Tere is a disconnect between this typical housing provision and what is required for a sustainable and equitable future for everyone.

Typical guiding principles for many (but not all) stakeholders in the housing industry are generally focused on refning the business model. Tis model was developed over many decades and is geared towards maximizing fnancial proft, often at the expense of improving housing quality and performance outcomes for households [3, 8–10]. Tis approach sees the provision of new housing and the renovation/retroft of existing housing as primarily a business transaction, taking advantage of any opportunity to reduce costs, time, or resources to improve the fnancial bottom line. Tis approach is not overly concerned with the housing consumer experience or with what happens after the completion of the dwelling or renovation/retroft project. Te broader housing sector would likely challenge this point and argue they are providing housing that consumers want, even if that does not align with what we need in relation to addressing the environmental and social housing issues discussed earlier in the book.

Te lack of care and consideration by much of the existing housing regime is evident through the amount of basic, as well as more signifcant, defects in many new dwellings. For example, recent research in Australia found that up to 85% of new dwellings in some jurisdictions contain defects such as cracks in foors or walls and issues with water proofng [11]. Financial and social defects do not only impact the homeowner [3]; defects also have signifcant fnancial impacts on those builders, developers and other key stakeholders responsible. For example, the cost of rework can amount to almost 5% of the overall project contract value [12–14], and can reduce company profts in some cases by approximately one third [15]. Te impacts of poor quality and performing dwellings can escalate into systematic issues where governments are forced to step in and provide fnancial or other supports. Te fammable cladding crisis (e.g., Australia, UK, Dubai) and the leaky homes/condo sagas (e.g., New Zealand and Canada) demonstrate some of the more extreme outcomes of systematic shortcomings across the housing sector [3].

In addition to issues surrounding quality of work, the wider housing sector typically builds only to minimum performance and sustainability standards. For example, in Australia, research into new housing construction found more than 80% of new dwellings only just met minimum regulatory requirements with less than 1.5% being designed and built to meet optimal cost and sustainability as outlined by researchers [16].

On the other hand, sustainable housing has been identifed by both researchers and sustainable housing advocates as having a completely different set of guiding principles, which have continued to evolve over time as the sustainable housing sector grows [1, 2]. Te drivers and motivations of sustainable housing stakeholders is not only centred on the housing consumers, but more largely on improved quality and reducing environmental impact—both in construction and during the life of the dwelling and household [17]. In efect, sustainable housing fips the thinking of the dwelling from being a place to sleep and eat to an opportunity to enhance the quality of life; it focuses on liveability and afordability for the household and shifts from short-term thinking to life cycle thinking. Te aim is to ensure that the impacts and benefts of materials, technologies, and other elements of a dwelling are considered across the life of a dwelling, including during the dwelling's end of life [18, 19]. Within this set of guiding principles, the idea of fnancial proft is not a dominant consideration. Instead, fnancial considerations are linked to what can be achieved within the set budget and is thought about more from the perspective of the wider fnancial, social, and environmental value provided.

With a focus on improving the quality of a dwelling, sustainable housing aims to mitigate the number and range of defects [3]. Tis is done through more thoughtfully considering design and materials. Tis is also achieved through delivering a quality project the frst time, which helps to reduce costs. Reducing costs can help to make housing more afordable from a capital perspective. If issues with quality did arise, a direct chain between the key stakeholders involved (e.g., builder) and homeowner allow for an open discussion on fnding a resolution. Sustainable housing also goes signifcantly beyond what is set within minimum building code requirements by taking a more holistic view of the key sustainability elements. Typical building codes have had a narrow focus or defnition of sustainability (e.g., focused on reducing energy for thermal comfort), but sustainable housing expands this to include considerations of water, transport, materials, and life cycle impacts with an increasing number of developments working to achieve outcomes within our current planetary means (e.g., one planet living and self-sufciency living).

Guiding principles of sustainable housing have evolved in more recent years to consider a range of diferent elements such as ensuring afordability (across the life of the dwelling), transparency of decision making, community collaboration, occupant health and well-being, and ethical supply chains [2, 20]. Tis evolution is also about supporting the sharing of intellectual property (including what has worked but also any issues that emerge) across stakeholders to enable a wider collaborative approach to advancing the work and knowledge of others. Tis has elevated how we defne sustainable housing—what it is and what it can deliver—not just for households, but for those in the housing industry engaged with providing, maintaining, and upgrading this type of housing.

#### **6.2.1 Living Within Planetary Means**

Living within our planetary means has become an increasing focus and a core starting point in terms of guiding principles for sustainable housing developments and retroft projects. Tis focus on reducing the ecological impact from housing, and associated practices that occur within housing, is not only about addressing climate change but also about overconsumption of resources. We have one planet, and that planet has a fnite number of resources and a limited capacity to replenish them [21]. Many examples have emerged over recent decades of individual dwellings and larger communities being designed, constructed, and used in ways that reduce the ecological footprint of the household and development down to near, or under, the resources required for living within our planetary means.

One example is the development of the rating framework 'One Planet Living',1 which was developed by Bioregional in the early 2000s to help developments achieve this outcome. A notable example of a development following this framework is BedZED (UK) which was completed in 2002 and is still widely recognized as an early exemplar sustainable housing development that went beyond just providing a technical solution and reframed the idea of sustainable housing through the guiding principles of living within our planetary means [22]. Another approach has been the (re)emergence of self-sufciency [23]. Te idea of self-sufciency is about living a lower environmental impact lifestyle and includes considerations for reducing fnance and resource waste through frugality, growing your own food, producing and collecting sufcient energy and water onsite, reducing debt, living simply, and even using local materials for construction [24]. For example, Earthship homes not only repurpose large amounts of consumer waste within the construction process but also focus on outcomes to help the household live a simpler life [25]. Both BedZED and Earthship homes prioritize quality and needs over wants and trends, and they aim to enhance quality of life, afordability, and overall sufciency and resiliency.

<sup>1</sup>http://bit.ly/3EVeLO0

#### **6.3 Physical Attributes**

Housing (noun) is defned as a dwelling or residence constructed for the purpose of shelter. Tis defnition is centred on the physical attributes of housing. Appropriate or adequate housing is housing that meets minimum construction and maintenance standards as determined by local authorities, and includes elements such as structural integrity, heating and cooling, lighting, ventilation, sanitation, and occupation. For this book, we defne the physical attributes of housing as the individual and combined physical elements of a dwelling. Examples of these elements include design decisions (e.g., passive orientation), use of materials (e.g., cross laminated timber), construction methods (e.g., prefabrication), and technology (e.g., solar PV).

Te design and construction of housing continues to be largely infuenced by the existing housing regime. While the design and construction of housing has slowly changed over time, it has done so within the confnes of the existing way of providing housing [26]. Tis includes that standard or "of the shelf", "tried-and-tested" designs, materials, and construction techniques continue to be replicated with limited innovations beyond a small percentage of houses. In large part, this links back to the guiding principles, with a signifcant percentage of housing construction industry stakeholders focused on maximizing fnancial profts. Having standard designs, material supply chains, and construction processes means that the process, costs, and risks are (relatively) stable and well known. Whereas, pursuing higher quality and performance standards or using new or diferent materials, construction techniques, or technology is perceived as challenging, adds to the cost of housing, or increases risks for delivering the project.

In part, this has also been infuenced by wider landscape-level factors, such as energy access and consumption. Decades of low cost centralized energy in many regions around the world has resulted in relatively low costs for operating housing. In fact, it has been cheaper and easier to put mechanical air conditioning systems into housing rather than improve the thermal performance, which results in an over-reliance on technology (and energy) at the expense of good design. With little demand for improved building quality and performance outcomes, and low energy bills, this approach has been allowed to continue. However, in the context of rising energy bills and the climate emergency, it is an approach that is no longer suited for housing.

Te physical elements of new housing and renovations of existing housing tend to be similar to previous housing unless otherwise specifed (and paid for) by a knowledgeable client, or if regulatory changes require it. Using similar practices for each construction project is perceived to ofer fnancial and logistical advantages, such as buying materials in bulk, building trusted relationships with supply chain stakeholders, and knowledge of working with the technologies or materials leading to controlling some of the variables involved in the construction (or renovation) of a dwelling [1]. While there may be a perception that the dwelling owner has signifcant opportunity to engage in the design, material, and technological decisions, this is often limited by what the industry (or specifc stakeholder) ofers. Subtle variations to a dwelling design can often add signifcant costs (and time) for a dwelling owner and they are often structured this way to dissuade consumers from wanting things outside the normal provision of standard housing.

As Smith [1] and others found, the existing housing industry is not typically focused on how to improve design, quality, and performance (e.g., life cycle considerations). Tere is often little consideration for materials used in construction in terms of where they come from and what their inclusion means for the building or household. Te focus is mostly around cost and ease of access. A just in time structure by many industry stakeholders to the ordering and delivering of materials also means that the construction industry needs certainty on product availability and costs, which has created familiar supply chain relationships that entrench practices. When sustainability elements are included, it is often the "bolt on" options (e.g., adding solar PV to a dwelling), rather than make deeper design and construction changes (e.g., improved insulation) to signifcantly improve the overall quality and performance of the dwelling.

Stakeholders involved in delivering sustainable housing think more holistically about the dwelling and centre on occupant needs. For the sustainable house (or renovation), designs typically begin from the ground up rather than trying to take standard designs and add sustainability elements to them [17]. In this way, sustainable housing providers can ensure they are maximizing key sustainable building technology and design principles such as orientation, passive solar, insulation, advanced window glazing, rainwater collection and storage, the use of local materials, and more. Incorporating these ideas from the start generally helps to reduce costs, both capital costs and through-life costs. To date, these sustainable housing stakeholders often have specialist sustainability design knowledge and/ or have learnt by doing and experimenting with what works (or does not work). As the number of sustainable houses being constructed or retroftted increases, key ideas around what design, material, and technology elements work means that future projects can build upon those that have come before without having to re-invent the design each time.

Te scale of sustainable housing has changed in recent decades. Earlier sustainable housing examples were seen as unique, one-of small-scale designs that were so far removed from the typical housing market that they were not considered feasible for many housing consumers. Te use of things like mud bricks, inclusion of of-grid renewable energy systems, or composting toilets were not seen as appropriate for the average housing consumer, nor were these approaches easy to scale up. As knowledge, understanding, and technologies have improved, there are increasing examples of sustainable housing that looks and feels like standard housing. In addition, with more evidence becoming available about the life cycle of various design decisions, materials, and technologies, there is a shift in focus from reducing occupancy impacts (e.g., heating and cooling) to reducing embodied energy impacts and considering what happens at end of life.

#### **6.3.1 Cross Laminated Timber**

An increasing area of physical attributes focus within the sustainable housing feld has been on material innovations in order to make sustainable housing scalable, reduce costs, and improve quality and performance. Cross laminated timber (CLT) is an example of such innovation [27]. CLT is an engineered timber product composed of multiple layers of two-dimensional lumber glued together perpendicular to each other and compressed tight. As a naturally fre-resistant product, CLT was frst used for walls, foors, and roofs in both residential and non-residential construction. Te benefts of using CLT include a high degree of prefabrication and of-site assembly, and compared to light-weight timber construction, CLT has less air permeability and more capacity for humidity and thermal energy. CLT is also able to act as a load-carrying element, which makes it applicable as a stand-alone structural element, and it is being used as a substitute for reinforced concrete. Tis makes it an appropriate substitute for reinforced concrete, helping builders reduce their carbon footprint as CLT is much less carbon intensive than concrete and steel. More recently, CLT has been used to construct tall timber structures of up to 18 storeys. Examples include "Treet", a 49.9 metre-high apartment tower in Bergen (Norway) design by architectural ofce ARTEC [28]; "Te Toronto Tree Tower",2 a 62 metre-high residential tower in Toronto (Canada) designed by Penda (now Precht); and "Carbon12",3 a 26 metre-high mixed-use building (residential and retail) in Portland, Oregon (USA) designed by Kaiser+Path. At the time of writing, there are proposed residential towers of 90 and 100 metres tall using CLT in Toronto and Switzerland, respectively. If built, these buildings would be the tallest mass timber structures in the world.

# **6.4 Knowledge**

Te housing industry approaches knowledge in a long-entrenched way. Tis involves standard knowledge development and reinforcing existing practices of providing housing. Knowledge across the mainstream housing regime has largely been developed by replicating tried-and-tested housing designs, use of materials and technologies, and construction methods. Tis has allowed housing construction industry stakeholders to refne their knowledge of what they do within the narrow parameters of standard practices. For this book, we defne knowledge as the "doing,

<sup>2</sup>https://bit.ly/3AZFBUh

<sup>3</sup>https://bit.ly/3VYiH7R

thinking, and organizing" of housing. Tis includes the access, understanding, and use of information to design, build, and sell housing.

Knowledge is informed by guiding principles in that there is a signifcant focus on business practices and the fnancial bottom line. Knowledge around building quality and performance generally is about meeting minimum standards, regulations, or planning requirements with the least cost, efort, and change to practices. Without a better understanding of design, materials, construction, and technology, the current housing regime can be locked into inefcient ways of ways of meeting minimum requirements as they attempt to "bolt on" additional requirements rather than redesign from the ground up. In addition to design and technology dimensions, the housing regime is primarily focused on individual dwellings or buildings and rarely extends to the role housing plays within the wider urban context.

Te housing construction industry is also generally protective of its knowledge and intellectual property. Tere is typically little sharing of knowledge, learnings, or lessons across the industry [29–31]. Tis stems from the focus on the fnancial bottom line and trying to eke out any market advantage possible. Tis approach also means that stakeholders rarely have the time or opportunity to return to completed projects to fnd out frst-hand what has worked well, what could be improved, and what the key lessons are, or even share this information across the industry [30]. Tis means that the wider housing industry is repeating issues that could be easily addressed if proper consideration, refection, and sharing on previous projects were conducted.

Tese knowledge sharing constraints not only exist within the industry but are also evident in how housing is marketed to consumers. Typically, marketing information relates to the price, location, number of bedrooms/bathrooms, and other perceived key amenities (e.g., garage, views), rather than providing information (or knowledge) about the implications of the design, materials, construction, and technology, which can signifcantly impact the quality and performance of a dwelling [32]. As noted earlier, this is reinforced by social norms about what a house should be, and the focus on wants over needs. Tere is also the lack of knowledge that housing consumers have about housing and their understanding around quality, performance, and sustainability. Tis is critical as wider housing industry stakeholders who push back against regulatory change often state that consumers have the knowledge of what they want and will use their purchasing power to drive sustainability change. However, research shows that housing consumers often lack knowledge about the impacts their decisions have on housing quality, performance, and design [33–36].

Sustainable housing stakeholders, on the other hand, are interested in information and knowledge as evidence to enhance their understanding and improve the design, construction, and retroft of housing. By weaving this evidence in with housing consumer needs, a more considered and holistic sustainability approach is applied. While such knowledge was site specifc in the early years of the sustainable housing movement, recent decades have seen the development of communal sustainable housing knowledge that is fexible enough to be adapted to diferent cultural norms, jurisdiction requirements, climate zones, and other local contexts (e.g., use of local materials). Tis knowledge is now integrated into many higher education courses related to the housing industry (e.g., architecture and construction management) to ensure those going into the wider industry have a higher level of knowledge and understanding to deliver sustainable housing. Tere has also been a focus on training for sustainable housing elements and delivering demonstration projects to reduce barriers of the unknown and to give actors experience with real-world outcomes [29–31].

Knowledge and evidence have expanded beyond just technical, material and design knowledge to include the role of the dwelling within the wider environment. For example, the focus on afordability through reduced utility bills, health and well-being through improved thermal comfort, and better productivity through improving natural light, and so on, are now as much a part of the sustainable housing language as the need to reduce the environmental footprint. Furthermore, improving housing performance based on what occurs around the dwelling is increasingly playing a role in the design, construction, and occupation of sustainable housing. Tis includes the strategic planting of vegetation to help regulate local micro-climates and reduce requirements for mechanical heating and cooling within a nearby dwelling.

#### **6 Socio-Technical Dimensions for a Sustainable Housing…**

Te sustainable housing community is typically a community that is open to sharing and has engaged with ideas around open sourcing key information. Tis is evidenced by the range of publications on the topic (e.g., books, articles, videos, podcasts, blogs) where people are happy to share what they have done [1]. Importantly, the community is also happy to share lessons of what has not worked, and to revisit these refections periodically to see if anything changes as the dwelling ages and households gain more understanding of how to maximize their performance. Increasingly, these niche sustainable housing stakeholders are engaging more and more with existing regime actors [1].

#### **6.4.1 Vancouver House/Vienna House**

In 2018, the City of Vienna and City of Vancouver signed a Memorandum of Cooperation to share knowledge and advance innovation in low carbon afordable housing across the two cities. Specifcally, the agreement commits the cities to 'share insights on innovative new building approaches, efective market transformation programs, and research associated with diferent building approaches and standards' [37]. Vancouver House,4 in Vienna, will consist of 107 rental units, a kindergarten, 12 units for assisted living, and 11 units for single parents in a hybrid wooden structure built to Passive House performance standards. Vienna House,5 in Vancouver, will consist of 123 units of dedicated afordable rental housing in a high performance, low emissions building showcasing innovative materials and design processes. Te knowledge exchange between the City of Vancouver and the City of Vienna has the potential to inform future sustainable and afordable housing projects. For this reason, knowledge transfer and dissemination will be a key part of the project's research and communications eforts.

Research on the buildings is publicly available through the project and government websites. In Vancouver, the University of British Columbia (UBC) is leading research through the UBC Sustainability Initiative, the

<sup>4</sup>https://bit.ly/3iuOP4b

<sup>5</sup>https://bit.ly/3GYDDXS

Department of Civil Engineering, and the UBC Collaborative Research Group. Researchers, students, and consultants will study the design, manufacturing, construction, and commissioning processes of the Vancouver project and document the challenges, solutions, and lessons learned. Potential areas of interest include energy performance, virtual design and construction (VDC), building information modelling (BIM), mass timber product performance, life cycle assessments, and prefabrication and construction productivity. Te aim is for the project to be a showcase or demonstration project for the housing construction industry, as well as for policymakers facing similar challenges.

## **6.5 Geography**

Te current housing regime has paid limited attention to geography. Geography refers to places and the relationships between people and their environments. Geography of transitions is concerned with where something takes place, asking 'why do transitions occur in one place and not in another? How do transitions unfold across diferent geographical context? [And,] What is the importance and role of relations at diferent spatial scales for transitions process?' [38, p. 93]. For housing, scale includes the dwelling, neighbourhood, city, regional, national, and international scales. For this book, we defne geography as the location (specifc place) and scale of housing.

As already noted, the typical focus of the current housing regime is one of maximizing housing outcomes for the lowest cost. Tis means that dwelling quality and performance can be impacted by both where a house is built and how it is built. Often impacts on quality and performance are locked in during the initial master planning of new sites, either by developers or by local planning authorities, rather than design development that is based on maximizing the performance outcomes of dwellings and the social and fnancial benefts for occupants [39]. Te initial planning stages lock in things like position of dwellings, road layout, and opportunities for active and public transport. With a focus on proft and only building to minimum planning and building code requirements, the current way housing is provided has had limited consideration of local context or larger urban or regional environments, such as the impact the dwelling might have on energy and transport networks.

Around the world, cities are experiencing increasing densifcation as populations grow and rural to urban migration increases. In response, there have been two main housing provision strategies. Te frst is increasing densifcation in areas close to amenities (e.g., public transport, shops, schools); the second is adding housing in urban growth zones and periurban regions. Both approaches have typically been delivered without signifcant consideration of place or the relationship between people and the environment. For example, there are numerous examples around the world of cities like Melbourne, Calgary, and Houston that have an everexpanding growth boundary that is driven by the perception of providing "afordable" housing in areas where there are no existing constraints in the built environment (e.g., no existing roads or buildings which infuence how new construction needs to be located). Tere is also the case that standard foor area of housing has increased in many regions over recent decades [40]. Combined with decreasing lot sizes, this constrains the ability to use the area around the dwelling to help improve performance (e.g., through tree planting to reduce the urban heat island impact).

Urban growth is often done at the expense of previous land use which, in some cases, has resulted in the loss of productive agricultural land and created wider societal issues around the provision of food. Tere are also examples of areas which have cleared signifcant native vegetation (e.g., forests, mangroves) to provide space for housing, which negatively impacts the local fora, fauna, and climate. Additionally, there are some locations which have been building on "reclaimed" land—land that might have been a swampland or waterway that has been flled in to build on. Tis can create many short- and long-term issues ranging from loss of nature to creating building performance and structural issues in dwellings. Te case of the Miami apartment collapse in 2021 is, in part, thought to have been caused by shifting reclaimed land on which the apartment stood [3].

Place and scale have also been important for shaping, and constraining, building regulations. While building regulations have been widely recognized as being critical in lifting performance and sustainability in both new and existing housing, it has been challenging to overcome issues which emerge through place and scale. For example, in some countries, regulations are developed at the national level and then passed on for individual states or regions to implement. Tis approach hopes to create a more consistent and level playing feld with regulations. However, as is the case in Australia and the USA (amongst others), this can also constrain outcomes when there is a need for agreement between regions on what is set at the national level. At times, this has resulted in a watering down of minimum performance requirements. Further, jurisdictions who want to push further ahead are either unable to or create their own requirements which can foster tensions across other regions or even with national regulators and the wider industry.

Sustainable housing has signifcant connection to place and community. Early examples of sustainable housing often used local materials (either onsite or from the nearby region) and demonstrated connection with, and to, the land where the building occurred. Ideas around having a "light touch" on the land or blending into the natural environment were often key objectives for sustainable housing. An increasing focus of more contemporary sustainable houses is on actively contributing to the local area wherever possible. Te provision of sustainable housing often starts by considering the site, materials, and designs that are best matched to the local climatic conditions. Tis helps to deliver improved performance outcomes in the initial planning stages, such as through ensuring that optimal orientation and passive solar opportunities are leveraged. It also helps to limit the loss of productive land (e.g., nature, farming) and ensure that the location of housing is appropriate (e.g., not in food zones or areas likely to be signifcantly impacted by future climate change).

Understanding the concept of place in transitions has become increasingly important. Explicitly acknowledging place provides important context to specifc transitions processes, including historical, socio-political, economic, ecological, and other contextual considerations (considerations that are limited within the current provision of housing). In addition to the location of transitions, the scale is equally important. Transitions can occur at a national level, state or provincial level, regional level, urban or municipal level, or at a neighbourhood or site level. In some instances, transitions can also occur across scales or they may be situated within a multi-governance context. Tis is relevant for exploration the sustainable housing transition as the provision of housing involves regulation, infuence, materials, technologies, and skills from across an increasingly globalized sector.

As sustainable houses move from one-of individual dwellings to the development of multiunit buildings and precinct scale developments, the benefts of the planning stage and understanding place and context is more signifcant for ensuring increased performance outcomes both within and across the development. At these early stages, local amenities are also considered and, in an increasing number of sustainable developments, are delivered either before or during the early stages of residential construction to ensure that the amenities are there when households start moving in and not years down the track. Sustainable housing stakeholders are also beginning to consider the role sustainable housing plays within the wider community and environment, and the implications it has for other sectors such as energy and transport where sustainability considerations can help make a positive impact beyond the individual dwelling or development site.

#### **6.5.1 Zoning Reform**

Single-family zoning, often referred to as R1 in planning documents, is a zoning policy that restricts development in an area to one dwelling per lot. Tis type of zoning is ubiquitous in the suburbs and other cardominated landscapes. Tere are calls and movements to eliminate singlefamily zoning, normally through "upzoning" which refers to increasing density on a lot. Te aim of up zoning is to increase housing in existing neighbourhoods. Jurisdictions across Canada and the USA are passing new zoning ordinances to allow more units on traditional single-family lots or to eliminate single-family zoning altogether. Tese jurisdictions are doing this to use land more efciently and environmentally, and to respond to housing afordability challenges. One of the most well-known examples of "upzoning" is the State of Oregon's House Bill 20016 which

<sup>6</sup>https://bit.ly/3GVBJHz

was passed in 2019. Te bill essentially eliminated single-family zoning across the state. For cities with populations greater than 25,000, the bill allows duplexes, triplexes, fourplexes, and "cottage clusters" to be built on parcels that are currently reserved for single-family houses. In cities with populations of at least 10,000, duplexes are allowed in single-family zones. Tis topic is receiving a lot of attention from planners, particularly in places like the USA. In 2020, the Journal of the American Planning Association published an entire special issue on the idea of ending singlefamily zoning [41]. Manville et al. [41, p. 106] argue that 'R1 is inequitable, inefcient, and environmentally unsustainable'. Meanwhile, Kendig [42] thinks eliminating existing single-family zoning is a mistake, and Chakraborty [43] believes this topic deserves more scrutiny.

#### **6.6 Industrial Structures and Organizations**

Industry actors such as frms and organizations play critical roles in sustainability transitions; they can be innovators and develop new ways of doing things, or they can restrict change and prevent the formation of new products, technologies, business models, and even new industries. Tese actors also engage in institutional work, where they participate in shaping cultural norms, regulations, and legitimize or shape new discourses. For this book, we defne industrial structures and organizations as the multiple actors and stakeholders across the traditional housing industry, including developers, builders, and manufactures. We are particularly interested in how the sector operates and how they organize themselves.

Actors in the existing housing regime have operated as a larger whole, with similar industrial structures, organizations, and industries dominating and protecting the sector against challenges (i.e., sustainable housing) and locking in entrenched practices of operation and organization. Te housing industry has been described as 'an institution [where] understanding the housing system requires recognizing its "rules of the game"' [44, p. 9]. Tese "rules" and the entrenched operating practices have shaped the way housing is provided. For example, to achieve cost efciencies, developers and volume builders are prevalent in many markets (e.g., Australia) and represent most of the new residential construction. Te preference of developers and volume builders is to develop larger detached housing estates rather than one-of dwellings. Tis provides opportunities for standardizing designs, materials, and construction processes and allows for controlling costs and maximizing profts, with the focus largely around fnancial outcomes. Tis also leads to developers and volume builders having established relationships with other industry stakeholders, which often carry over from one project to the next. Te operation, practices, norms, and discourse across similar actors in the industry are also established and enacted through peak industry and professional associations [44]. Again, there are fnancial and other efciencies for maintaining these relationships, but it leads to doing things the way they have been done previously.

In many regions of the world, the wider construction industry is one which is heavily based on subcontracting labour. Tis has a range of implications including that it creates, to some degree, a transient workforce that follows the money or work with little connection to the employer (other than to ensure they get future work), the end product (with accountability passed back up the management chain), or the community (no knowledge of the local environment). Tis has created mixed outcomes with research showing that the length of time to build a house in places like Australia is increasing, and that part of this additional time is due to diferent trades and subcontractors having challenges sequencing their components of work [45]. Tis structure of employment also means that there is limited incentive for subcontracted workers to report issues or learnings to those in decision making roles. As such, the cycle of continuing to produce the same type of housing continues.

While some smaller builders or developers may just work on a single project at a time, many medium-to-larger building companies or developers often have multiple projects underway at any one time. Part of this relates to market structures and helping to diversify risk and costs by spreading the risks and resources across multiple projects. It can also help with organizing the workforce. For example, if diferent trades can be sequenced across multiple projects, it can be more productive and fnancially benefcial for both the builder or developer, and the labourer. It also means that trades can be moved to diferent sites should the need arise to do certain work or meet deadlines. However, this also means that the current housing sector is highly reliant on a small number of organizations and, as increasing research fnds, this is challenging to do and results in delays and other outcomes.

Te current provision of housing is also heavily reliant on a select number of key industries and supply chains. Increasingly, the housing sector is becoming more globalized and a key result of this is a reliance on international supply chains for materials and technologies in many jurisdictions. Tis has largely been driven by the pursuit of fnding cost efciencies, but is in part driven by a decline in manufacturing in many regions which has forced housing industry stakeholders to look elsewhere for the materials and technologies required for housing construction. While this has helped to improve the bottom line of some stakeholders, global supply chain issues during 2020–2022 have highlighted the overreliance on this structure with material and technology shortages and skyrocketing costs. Tis has contributed to developers and builders going bankrupt when they have been unable to deliver on fxed cost contracts for construction [46].

For a long time, sustainable housing has been seen as bespoke one-ofs or small groups of housing delivered by specialist designers and builders [1]. It has historically been a process where early adopters (both industry and households) have learnt by doing and attempted to fx any issues that arise along the way. As the previous dimension explored, this process has also involved sharing knowledge and learnings with the wider sustainable housing community [1]. While sustainable housing has typically been attempted with the constraints of budget in mind, there have been cost premiums for some sustainability elements and inclusions for early adopters, such as with the higher cost of solar PV and battery storage. Tis cost premium has been used by the existing regime as a key reason why sustainable housing should not be more widely pursued.

However, sustainable housing has shifted over the past decade or so, from high levels of experimentation in one-of projects to replication of prior learning and upscaling [29]. Tis has not only had an impact on the scale of sustainable housing, but has also helped pushed the performance benchmark of housing forward. In part, this is driven by increasing knowledge and cost reductions for materials, construction methods, and technologies. Sustainability is no longer seen as a premium feature; when sustainability is designed in from the start, it can be achieved with signifcant design and cost efciencies. Te cost of key sustainability technology has continued to fall, making it even more afordable to include elements such as solar PV on homes. Tis decrease in costs along with a change in housing culture has encouraged some sustainable housing actors to cap profts to ensure that decisions are ethically driven and they beneft the homeowner and the environment. Tis change in approach has also pushed actors to work with the fnancial industry to fnd innovations to fund sustainable housing construction.

Within transitions research, there is an increasing focus around the industrial structures and organizations involved in transitions. Tis is relevant for our focus on the sustainable housing transition and has been explored from a range of perspectives, including understanding business practices (e.g., how to develop, protect, and/or elevate key or new structures), organizations, and industries to help challenge incumbent regimes [47–50]. Given our discussion across earlier chapters, the provision of sustainable housing will likely require housing industry actors and stakeholders to adapt or evolve. However, Sovacool [51] and others are increasingly concerned with the slow pace of transitions. For example, if the pace of transition is too slow, the incumbent regime is more able to resist change or make minor changes to continue provision of houses without including wider sustainability considerations. Speed is a pertinent issue for sustainable housing given that housing is a long-life infrastructure likely to last 40 or more years once built.

An important element already emerging in the sustainable housing transition has been around challenging traditional notions of fnance and afordability. Within the wider transitions literature, there is an increasing focus on the role that fnance capital plays to enable or constrain transitions [52, 53]. Given that existing housing regime practices have largely been enabled by the wider market, it stands to reason that the market, and specifcally the fnancial structure and organization of the market, must change. Tis has been noted by the UNEP [54] in relation to sustainable development. Wider research has also stated that the fnancial recovery from COVID-19 will be greater with a shift towards delivering improved sustainability across a range of sectors [55, 56]. Within the housing sector, there is a need to shift the way housing is viewed in terms of cost, value, and afordability. Furthermore, transitions researchers have highlighted the importance of new ways of doing, thinking, and organizing and the role that innovation (such as digitalization) will have in restructuring various industries and sectors [57–59]. Te emergence of several innovations in recent decades, such as prefabrication, has highlighted how this might play out within the sustainable housing transition and associated sectors such as considerations of energy as a service.

#### **6.6.1 Prefabrication**

Prefabrication, or prefab as it is commonly referred to (or in some locations, of-site manufacturing), is construction undertaken away from the fnal building site in a factory-like setting. Once constructed in the factory, various prefab elements are taken to the building site where they are assembled. Tere are diferent types of prefab including modular (large modules of rooms or sections of a home including the structure and fnishes of roofs, walls, and foors and any built in elements such as kitchens, bathrooms, storage, and all electrical and plumbing) and panelized (where smaller sections of the home are built before being assembled into the larger structure onsite). Benefts of prefab include that it can deliver improved quality, reduce material and labour waste during construction, improve construction safety, shorten construction times onsite, reduce construction costs, create less disruption to neighbours, and reduce project risks [60–62]. Prefab ofers innovation and new ways of providing housing which challenges the established cultural practices, norms, regulations, and discourse around housing design and construction. It also presents a diferent way for how the sector can operate and how they organize themselves. For example, constructing in a factory means that work is not impacted by weather, and improving sequencing of trades can improve overall efciency by reducing construction time and costs [62]. In this way, prefab changes business practices and challenges incumbent regime actors.

Some countries have embraced the use of prefab over recent decades, while others have only more recently engaged with this diferent construction approach. For example, Sweden is considered a leader in the prefab construction of housing, having been constructing housing in factory-like settings since the 1940s with prefab now representing over 80% of the housing market [61].

#### **6.7 Markets, Users, and Power**

In many regions of the world, the politics around the provision and maintenance of housing has been focusing on three key deliverables: the provision of more housing, afordability (capital costs), and getting a higher percentage of people into home ownership. Tis means that decision makers must often consider trade-ofs from any new regulatory changes against the impacts on these three deliverables. Requirements for improving the performance, sustainability, and quality of housing have typically been portrayed by the incumbent housing regime as negatively impact these key deliverables. Tis narrative has been playing out across diferent housing markets and with diferent users tied to diferent housing situations. Tis creates a complex landscape for decision makers to navigate. For this book, we defne markets, users, and power as where and how housing is sold or exchanged (markets), the consumers or occupiers of housing (users), and the politics and regimes, including government and industry players, that dominate the housing sector (power). Markets, users, and power are also about the complexity of relationships and the interactions across these entities as well.

Te current housing regime has power and agency over the frst policy levers pulled when the economy starts to decline. However, the housing construction industry can often leverage the politics around construction to suit its position. Governments regularly collaborate with the housing construction industry on new policy initiatives, often through a process of negotiation where there is signifcant power on the side of the construction industry. An example of this is when the Victorian Government (Australia) announced plans to put a small fnancial levy on residential developments over a certain size (3+ dwellings) to help create a social housing fund to build more afordable housing for those most in need. Days after the Victorian premier announced this plan, he was forced to withdraw the proposed policy changes after he claimed the construction industry withdrew its support for the plan despite it having signifcant beneft for them [63].

Te housing construction industry also has signifcant power and agency over housing consumers and is notorious for saying it strongly engages with the housing market and users and aims to deliver what users demand. Time and time again, studies fnd this is not the case and that housing consumers have limited agency. Te notion of the "free market" is often put forward with the housing sector arguing that, if consumers wanted higher quality or more sustainable housing, they would ask for it and be happy to pay for it. However, research has found that consumers do not have a clear understanding of what sustainable housing is, what benefts it can provide, what opportunities are available to them, and how to go about asking for something that is portrayed as "diferent".

Because misinformation proliferates sustainable housing discourse (e.g., added cost), consumers do not have clear and unbiased information about sustainable housing. Social norms around housing are also reinforced by key actors beyond the housing sector, such as building or renovation shows where the focus is on the fashy, nice to have elements, with little consideration for quality and performance. Tis helps reinforce ideas around what housing should or could be. Terefore, the idea of the "free market" is not really working in this context. In regions where volume builders dominate, the housing consumer often has limited opportunity to be engaged in the process beyond selecting a template design from a limited range and some "custom" additions that are available.

Sustainable housing difers from the current regime as it has a longstanding practice of collaborating with housing consumers and key stakeholders of the design and housing construction industry. A collaborative approach like this means consumers are aware of all key decisions and their implications. Tis practice ensures that the needs of the household are met and environmental impacts are reduced. In the earlier days of sustainable housing, there was a high level of user involvement as many sustainable houses were self-built or custom projects. Tis has evolved to some degree (from one-of projects to larger scale, industry-built developments), but there is still a strong tradition in self-built sustainable housing in the growing community of tiny houses and of-grid projects. For industry-built sustainable housing developments, there often remains some user involvement throughout the design and construction process, as well as in the management and maintenance phase, to maximize performance outcomes. In some cases, collaborative engagement also helps to educate future residents about diferences between sustainable housing and traditional industry-built dwellings.

Te sustainable housing construction industry has had limited power over policy makers. At the moment, sustainable housing is still fghting to have their voice heard. Tis is despite providing an increasing number of successful examples of developments that provide a range of benefts. While sustainable housing may not have political power, we have recently seen a upscaling of sustainable housing development within the existing constraints of regulation, fnancing, and the wider housing regime (see Chap. 7). Te sustainable housing industry's ability to infuence and deliver change will grow alongside the sustainable housing movement grows. As more housing consumers start to understand the impacts of housing decisions on longer term liveability and afordability, users are helping to shift power dynamics for sustainable housing. Tis shift is also starting to occur with other housing provision stakeholders, such as fnancial institutions working with niche developers or funding sustainability retrofts.

Sustainable housing actors and the current housing regime have often been likened to David and Goliath, with the current regime holding the power. Tis dynamic plays out within sustainability transitions theory, where the regime is the dominant social order and niches are small-scale interventions, radical innovations, or experiments that push for bottomup change. Regime actors often use their power to actively resist transitions in various ways [64], whereas niche actors try to change the regime [65–67]. As part of housing transitions research, scholars have examined diferent elements relating to specifc sustainable housing niches [68], as well as the relationship between sustainable housing as a niche and the existing regime. However, as sustainable housing continues to evolve and become more embedded within housing practices, the power dynamics between sustainable housing and the current regime will have to be refned and possibly redefned.

#### **6.7.1 Rating Tools**

In many locations, minimum performance requirements (including rating tools) have been used to lift the bottom of the market. However, typical rating tools often focus on reducing energy or carbon metrics through purely "technical" elements, rather than design, material, and social considerations. In response to these limitations, an increasing number of voluntary rating tools have emerged in recent years, working to reframe ratings and measurements to be about improving outcomes for occupants and the wider environment as a whole [69]. For example, the WELL Building Standard,7 which was launched in 2014 and has now been applied to more than 21,000 buildings in over 120 countries, has developed a rating tool which uses medical research as a starting point to improve occupant health and well-being outcomes. Certifed spaces are designed to address Seven Concepts of the WELL Building Standards: Air, water, nourishment, light, ftness, comfort, and mind. In doing so, outcomes improve the nutrition, ftness, mood, sleep patterns, productivity, and performance of the people working, living, shopping, or playing inside these spaces. Building the tool from medical evidence has resulted in a more user focused outcome and, to some degree, takes away the input from the "free market" as it is based upon the best available evidence rather than infuenced by consumer trends.

Another more innovative rating system challenging markets is the Living Building Challenge,8 launched in 2006. Tis tool attempts to radically change the way we consider, design, build, and use buildings and has been described as the world's most rigorous building performance standard.

Where other tools try to reduce environmental harm, this tool aims to make a positive contribution to the environment by being regenerative (i.e., fxing the damage). For example, it sets targets beyond what is needed to support just the building, such as 105% renewable energy generation. Like the WELL tool, the areas of focus are diferent to those of

<sup>7</sup>https://bit.ly/3FgcTAL

<sup>8</sup>https://bit.ly/3Fj6qW4

traditional tools and include place, water, energy, health and happiness, materials, equity, and beauty.

#### **6.8 Policy, Regulations, and Governance**

Within the sustainable housing space, housing and built environment researchers have been paying a growing amount of attention to the role of policy, regulation, and governance in maintaining status quo within existing housing (or built environment) regimes [70–73]. Tese researchers have also begun to explore how diferent policy, regulation, or governance approaches have, or could, help facilitate sustainability transitions. Tis has included evaluating diferent policy, regulation, and governances approaches and identifying key mechanism to help with upscaling the provision of sustainable housing. For this book, we defne policy, regulations, and governing as the rules of engagement for the housing industry that are set by the government. Whereby, the government governs the housing industry using mandatory and voluntary interventions or directives.

Te existing housing regime is characterized as an industry that broadly wants less policy and regulatory interference from governments. Te perspective is that any development or increase in policy or regulation would negatively impact the industry being able to deliver what the market wants. While regulations for minimum housing quality and performance are not new (see Chap. 2), the past 20 years have seen an increasing focus on policy to lift minimum requirements for new housing and retrofts. Tis challenges the status quo of the current regime which is forced to reorganize the way it provides housing. For the most part, policy changes have been made in incremental steps (in comparison to what is required for a low carbon future), and the wider housing industry has largely been able to adapt to changes by adding on sustainability elements rather than requiring deeper, structural changes. However, as housing quality and performance requirements head closer towards a zero carbon requirement, it is harder and harder for the housing industry to meet higher standards without having to make those deeper changes.

While most in the housing industry largely adhere to minimum land use and building regulations, there is often a lot of push back against increased sustainability requirements. Tis rejection of additional requirements is often under the guise of not wanting to inhibit innovation or drive up the cost of housing [74]. Critiques to proposed policy changes are important and should occur, but much of industry push back is based on dubious evidence and misinformation. Tis has resulted in slow progress towards lifting minimum performance requirements (or, in the case of the UK's Code for Sustainable Homes, removing it all together) and other policy changes. What is left is a largely self-regulated industry with few checks and balances. In countries like Australia, there has been a long history of self-regulation which has arguably contributed to signifcant building quality and performance issues such as the fammable cladding crisis and dwellings not even meeting minimum sustainability requirements [3].

Sustainable housing has both benefted and been constrained by the development of planning regulations and building code requirements. While both planning and building codes have evolved over time, early examples of sustainable housing often had to demonstrate how they met and exceeded minimum building requirements. Tis created additional challenges for early sustainable housing projects as many sustainable housing elements fell outside the typical ways of doing housing. Current performance standards have increased, and many jurisdictions use energy rating tools, but sustainable housing providers are still facing challenges as they keep innovating and pushing the boundary of sustainable housing. Tis is primarily due to problems of demonstrating improved performance when the regulatory systems have not kept up with new developments in terms design, materials, construction, and technologies. Unlike the current housing regime, sustainable housing advocates typically want to see more changes in policies and regulations.

However, there is increasing research, policy, and industry recognition that the provision of more sustainable housing cannot be solely driven by a top-down governance approach and that a range of actors and other approaches (including policy and regulation) will be required as part of the transition. Part of this rationale is from the uncertainty around how to upscale sustainable housing, with the possibility that other actors, designs, materials, technologies, and construction approaches may be needed to deliver this transition at scale. In response, there have been various experiments and urban living labs developed in recent years [31, 75–77]. Essentially, these are places and spaces where additional protection is provided (often by government) to allow sustainable housing innovations to attempt to establish themselves [76, 78]. Tis is important for creating and establishing new rules around "doing" housing and urban development and exploring what works, or does not work, without typical pressures or restrictions. Urban living labs are not just about testing feasibility; these experiments show the wider industry what can be done and help to establish the supply chains and other changes required to deliver such an outcome. Te role of demonstration through exemplar projects has been critical in recent years to help shape and reshape policy and regulations.

Transitions seek to change governing arrangements, markets, culture, meanings, language, infrastructure, technologies, practices, and networks. Te challenge is how do these changes occur? In the housing sector, this is often done by developing policies and establishing new regulations [79], by creating "protected spaces" for innovations to occur [80], or through demonstration or pilot projects [30]. Tese actions and initiatives are established by governments with the aim to either enhance the top end of the market or bring the bottom of the market up. Sustainable housing primarily sits within the top end of the market, while many in the existing housing industry are at the bottom end. A major challenge is fnding a balance that pushes the existing regime to deliver better outcomes without constraining sustainable housing [1]. A second major challenge is related to governance; while most of the policies and regulations are introduced by governments, the private sector has a lot of infuence, particularly in some jurisdictions.

Over recent years, the sustainable housing movement has evolved beyond just advocating for improved policy and regulations. Sustainable housing advocates are now challenging the existing governance and industry regimes on multiple fronts. Tis includes locating the need for sustainable housing within the climate emergency, energy resiliency challenge, and addressing wider social outcomes like fuel poverty and health and well-being outcomes [81–84]. In this way, sustainable housing has shifted within the policy, regulation, and governance discourse from a technical challenge to a more holistic focus on social and environmental outcomes. Part of this shift has been calling for greater compliance checks across the industry to ensure that quality and sustainability issues are not only met, but that there is increased well-being and a level of protection for housing consumers [3].

#### **6.8.1 Banning Fossil Fuel-Based Heating**

With the goal to cut greenhouse gas and methane emissions by transitioning to electric heating, jurisdictions around the world are banning certain kinds of fossil fuel-based heating systems in new home construction. Tese bans are a response to the Paris Agreement's 2050 targets and the UN's Sustainable Development Goals which include the move away from polluting fuels. Bans are taking place at the national level across the European Union,9 at the provincial level in Quebec,10 and at the local level in places like Dublin,11 New York City,12 and Vancouver.13 Denmark was an early leader in introducing such bans, with the installation of oilfred boilers and natural gas heating banned in new buildings in 2013 and all buildings in 2016.14 In Quebec, oil-powered heating for new construction projects was banned at the end of 2021 and, in 2024, it will be illegal to replace existing furnaces with fossil fuel powered heating systems. Te province is trying to reduce emissions related to heating building by 50% by 2030, and with 60% of household emissions coming from heating, transitioning to electric heating options makes sense. In Vancouver, starting in 2022, equipment for space and water heating in new low-rise residential buildings must be zero emissions, and by 2025, all new and replacement heating and hot water systems must be net zero. Currently, burning fossil fuels in buildings represents 57% of Vancouver's

<sup>9</sup>https://bit.ly/3B25iDv

<sup>10</sup>https://bit.ly/3Vxmp86

<sup>11</sup>https://bit.ly/3H1tPfY

<sup>12</sup>https://bit.ly/3XQ0vi8

<sup>13</sup>https://bit.ly/3gMY4fU

<sup>14</sup>https://bit.ly/3GW4aoN

carbon pollution, so drastic policy changes are needed to help the City reduce its emissions.

#### **6.9 Everyday Life and Practices**

Te dimension of everyday life and practice draws on social practice theories that focus on practices as a unit of analysis where change is understood in terms of transitions in practice [85]. Much practice theory research tends to focus on the performance of practices—the "doing" of everyday life, the elements of which it is comprised, and the ways practices are socially constructed [86]. Practices are performed by people; here, we focus on housing users. Users are active players in transitions processes; contribute to new innovations in technologies, products, and practices [87]; and champion change [88]. In addition to consumers, users can also be voters within democratic institutions and participants in political and social movements [89]. For this book, we defne everyday life and practices as the activities that are typically and habitually performed in everyday life by individuals, including cooking, showering, and going to work. For housing, we are interested in how dwellings are used and how we might change those practices.

Te current housing regime has had limited consideration for current or future households or users, including how these users use and manage their dwellings both in the short term and across the life of the dwelling. As noted in Sect. 6.6, users have often been seen as passive or silent actors in the provision of housing. When users are considered, it is often around elements of the dwelling, such as materials and technology, that are perceived to attract more housing consumers. Tese include the size and fnishes of kitchens, and number of bathrooms. Tese elements are marketed as elevated elements and work to change social norms about what to expect from dwellings. It was not long ago that many houses would have had a single bathroom, but now an absence of multiple bathrooms is seen as a negative [26].

While there have been a variety of changes to housing design and technology, the current housing regime has primarily focused on the role of technology in delivering improved outcomes: for example, the focus on delivering improved thermal comfort by using more technologies (e.g., a mechanical heating and cooling systems) rather than through materials, passive design elements, building orientation, or landscaping. For many regions, this has created unsustainable practices for occupants. Tese unsustainable practices are often supported with policies and design, and performance-rating tools where assumptions are made around an "average" user. However, averages range geographically and demographically. Tese assumptions range from the hours people are at home, the temperature set for heating and cooling systems, and the location of housing. Assumptions like these remove agency from users and impact current and future outcomes.

Sustainable housing starts with the (initial) users at the centre of its thinking. Sustainable housing users have been critical for the development of a wider sustainable housing community and helped shape, or reshape, policy and social norms. Questions around how the dwelling can improve a range of household outcomes (e.g., liveability, afordability, and health and well-being) are often just as important as the environmental impact. Increasingly, these questions are not just about the individual household, but also about how a dwelling can infuence and facilitate changes in everyday life and practices. For some sustainable housing providers, this has meant moving away from a technologyfocused approach to providing more agency to users through the day-today management of their dwelling (e.g., needing to open and close windows or lowering and raising blinds to help regulate thermal comfort and performance) [90]. In addition to increased agency, this also makes the dwelling more resilient to technology failures. However, this is not an argument against technologies; they still have a role to play in improving performance outcomes. For example, the electrifcation of housing and mobility, through smart home technologies, solar PV, electric vehicles, and two-way battery charging, have created benefts related to improving efciencies within dwellings and lowering environmental impacts. Tese improvements have also enabled easier (or more comfortable) ofgrid living.

Despite attention paid on the ground, wider transitions research has had limited interest in user practices, consumption, and the everyday life. Where it has been included has largely been in the more technology focused studies [59, 91–94], including within the housing and built environment and wider energy space where a number of papers have emerged in recent years. Early adopters of diferent design approaches, material selection, and technologies were guinea pigs testing out how things worked, and they often paid higher capital costs for the privilege [95–97]. Te experiences of sustainable housing advocates and users, demonstrates the role they can play in helping to guide and accelerate transitions through diferent (re)confgurations of structures, networks, and rules of the game to challenge the existing regime.

#### **6.9.1 Electrifcation of Homes**

Te move towards the all-electric home has become an increasing focus amongst some stakeholders in the sustainable housing space [98]. While the use of natural gas (and other resources such as wood) was initially seen as a more sustainable energy option as compared to fossil fuel electricity, this view has been revised in recent years due to the increase in renewable energy generation and the emerging evidence for the wide negative impacts of gas and other fuel types (e.g., on health and wellbeing). Electrifcation of homes has been identifed as an important step towards not only delivering a more environmentally sustainable home, but also delivering a home that is more afordable to operate (due to paying for only one energy type, which avoids connection fees) and is healthier for users. Te move towards electrifcation has been identifed by researchers and policy makers in diferent regions as being feasible and important for achieving wider decarbonization goals. Research has also identifed how an existing dwelling can transition to an all-electric home by replacing various gas (or other) appliances as they are due for replacement.

While evidence for the benefts of the all-electric home has emerged, it has been housing users, rather than policy makers, who have been actively driving the translation from research to practice. Sustainable housing users have been repositioning themselves from passive or silent actors to actors that actively shape and reshape housing, social norms, and even policies. Tis was not simply a matter of changing appliances or the energy type but has also required associated changes to practices (e.g., using appliances when sufcient solar energy is being generated, or adapting to diferent ways of heating and the diferent feelings of warmth those approaches delivered). In places like Australia, the ground up support for the all-electric home has grown signifcantly in recent years (as exemplifed by the My Electric Home Facebook group15 which now has over 70,000 members) and this ground up support has pushed back on government requirements to have gas connected to new housing, resulting in households removing gas connection from existing housing at record numbers. In 2022, this resulted in the Victorian government announcing that it would change requirements to allow for new housing developments to proceed without connection to gas infrastructure.16 However, despite increasing support for all-electric homes, sustainability benefts may fall short if electrical grids rely on fossil fuel energy. A wider energy transition away from fossil fuel infrastructure is also needed.

# **6.10 Culture, Civil Society, and Social Movements**

Te shift towards more sustainable housing represents a change in culture. For the existing housing industry, the culture around housing is represented by markets and regulations. In contrast, early iterations of sustainable housing were about delivering more sustainable homes, where sustainability was both the outcome and the culture. More recently, we are seeing sustainable housing advocates and providers delivering models that are challenging traditional cultural norms around diferent elements of housing, including fnancial, social, and community elements. For this book, we defne culture, civil society, and social movements as individuals and organizations challenging and changing the status quo. Change can come from anywhere, inside or outside the regime. We are particularly interested in changes that go beyond individual dwellings and work towards a reconceptualization of housing.

<sup>15</sup>https://bit.ly/3XNUO4A

<sup>16</sup>https://bit.ly/3gQjLLT

#### **6 Socio-Technical Dimensions for a Sustainable Housing…**

In many regions of the world, housing has been delivered via the use of a "less is more" regulation approach and a reliance on the wider consumer market to demand improvements or changes. Tis has resulted in the replication of tried-and-tested housing typologies, design, materials, and technologies with a business model focused on improving the fnancial bottom line rather than quality and performance outcomes for housing consumers. Key housing regime actors, such as peak industry bodies, continue to push back against calls for increasing minimum regulatory requirements for quality and performance of new and existing housing. Regime actors are not seriously engaging with the wider structural housing issues created and propagated over recent decades, rather they are protecting the status quo. Tis creates a range of challenges to shifting the housing industry, and housing consumers, towards a low carbon future.

Sustainable housing has emerged as a new culture within the larger housing industry. Tis culture is tied to ideas and actions around how housing can be more sustainable. Sustainable housing has been exploring diferent ways to deliver housing and, in doing so, has established new customs, values, and norms across industry stakeholders and consumers. In the earlier years of the sustainable housing movement, sustainable housing was not primarily about replacing unsustainable materials and technologies with sustainable ones; it emerged more as a bottom-up rethinking of housing across all elements of design, construction, and use. For example, it acknowledged that bigger was not better and that improved design functionality could improve small-space living, and argued that materials should be considered for their durability and ability to improve thermal comfort (not solely aesthetics) as well as for considering the end of life for materials and whole dwellings [7, 99]. Tese examples represent a shift towards sustainability in the culture of building and designing housing.

Social movements around sustainable housing, at local and international scales, have been instrumental for challenging the housing status quo. Such social movements were developed of the back of wider movements engaging with ideas of sustainability, as well as from the desire to share and learn across sustainable housing projects [100]. Earlier on, these movements were grassroots, both in terms of scale (one-of projects) and actors (non-regime or traditional housing industry). Sustainable housing communities were created through initiatives such as eco-villages and co-housing developments, which allowed like-minded people to come together and elevate the benefts of sustainable housing. Tese communities also served as a place of learning where ideas could be replicated in neighbouring building, or where communities could serve as inspiration for new developments. Finally, sustainable housing communities are encouraged thinking across buildings to consider benefts at a larger scale [101]. Tis helped to shift the sustainable housing culture from focusing on individual dwellings to considering the role of these dwellings within the larger urban environment and wider community.

Within the wider transitions literature, there has been an increasing interest in the importance of culture, civil society, and social movements and how these play critical roles within sustainability transitions [102–104]. Tese elements challenge the current ways and rationale of doing things and can create wider culture change through changing social norms, values, and everyday practices [102]. In doing this, they help create protective spaces for innovation and shape the support and efectiveness of transitions policies. Tere has been some focus on these points within a framing of sustainable housing transitions. Our own work, for example, highlights that wider culture, civil society, and social movements are evolving not just within the sphere of direct stakeholders designing, building, and occupying sustainable houses, but within a much wider reach of stakeholders who intersect with the transitions process such as fnancial institutions who fund housing development [2, 65].

#### **6.10.1 Renew—Organization and Sustainability Magazines**

Renew17 (formally the Alternative Technology Association) is an Australian not-for-proft organization that was established in 1980 to provide inspiration, information, independent advice, and advocacy to help people live more sustainably in their homes and communities. Te organization is involved in a wide range of activities including

<sup>17</sup>https://bit.ly/3ERjCji

undertaking sustainability consultations, providing free advice to members, organizing and hosting webinars and events (including a Speed Date a Sustainability Expert and annual Sustainable House Day event), and publishing two quarterly sustainability magazines: *Renew—technology for a sustainable future* (with over 160 issues) and *Sanctuary—Modern green homes* (with over 60 issues). Te organization and publications engage with more than 250,000 people each year and have an active membership of 11,000 people (2020–21). Renew has played a key advocacy role in driving recent regulatory changes in Australia through disseminating research and continued supporting dialogue with key stakeholders (including households). Beyond just a focus on the physical home or technologies, Renew is increasingly evolving to include spaces around houses and communities (such as gardening and urban greening), new considerations of housing such as the role of electric vehicles, and addressing future climatic and resiliency challenges as a community. For example, issue 60 of Sanctuary magazine was a food resilience special. Trough these various activities, Renew has helped reconceptualize housing and sustainable housing for Australian households through a largely bottom-up community approach and, in the process, has managed to help establish new customs, values, and norms.

## **6.11 Ethical Aspects**

For decades, ethical considerations for the design, construction, and maintenance of new and existing housing have been at the centre of research and advocacy work. However, these issues have received less attention within sustainability transitions scholarship. Tis dimension draws upon many of the previous dimensions in relation to the way the current housing regime operates, focusing on how these operations impact ethical aspects of transitions. For this book, we defne ethical aspects as good governance practices and considerations of poverty, justice, and inclusivity. In addition, we emphasize equity, rather than equality, to ensure that everyone has an opportunity to participate in a way that is appropriate for them.

Te housing sector is largely driven by guiding principles and business practices that prioritize maximizing fnancial proft over quality, performance, and occupant outcomes. However, this fnancial lens on housing has meant dwellings are too often distilled into fnancial outcomes, rather than considering the wider social, environmental, and through-life benefts of improved quality and performance. As we explored in the earlier chapters of this book, this framing around the capitalization of housing has impacted wider social outcomes including poverty, justice, and inclusivity [81, 84, 105–107].

Tis fnancial framing, along with consistent push back against increasing regulations or compliance requirements, has led to a housing industry that does not prioritize ethical considerations or consider the wider climate emergency context. While individual stakeholders are not likely setting out to be unethical, the industry's engrained practices and the short cuts or lack of checks and balances can add up to negative outcomes. Tis is evident in the rise of minor and major building defects in new dwellings, and the signifcant challenges that housing consumers face trying to get these issues addressed. Notable examples include the use of asbestos, leaky homes, and the fammable cladding crisis [3]. Te shift of the construction industry from being a more local industry to one that is part of the globalized network is another example of unethical practices. As supply chains have become more globalized, there has been limited oversight which has led to major environmental impacts from some materials and technologies, and has supported modern slavery practices.

Sustainable housing attempts to address a number of these ethical issues that have emerged through the current housing regime. Tis includes addressing things like the ethical considerations in supply chains and modern slavery (e.g., doing checks on where materials come from and how they are manufactured and ensuring everyone is paid a fair wage) [108, 109]. It is not just about ensuring ethical practices at the global level, but also shifting back towards using local material and labour where possible to help local economies. Tere is also an increasing focus of sustainable housing stakeholders on how quality housing can be provided not just for those who have wealth and resources, but also for vulnerable and marginalized households who are often left behind in the move towards a more sustainable future. Tis includes being able to provide such housing for low income households, renters, the unhoused, and so on. Tis is partially in recognition that the benefts of sustainable housing are likely to have even greater benefts for health, well-being, fnance, and social outcomes for these vulnerable housing cohorts. In this regard, sustainable housing has been discussed as being able to help wider ethical and justice considerations such as addressing the increasing rates of fuel poverty around the world.

It will not be possible to knock down and rebuild all existing housing to a higher quality and performance level, so the attention in recent years has shifted to the necessary role of deep retrofts on existing housing. Tere are ethical considerations wrapped up within this focus, with the idea that we leave as many raw resources "in the ground" as we can for future generations. Tis symbolizes a growing movement within sustainable housing consumers that housing must be seen as long-life infrastructure. It is no longer just about the frst or current user, but about what happens across the life of the dwelling. Increasingly, this is being considered within the context of a changing climate, and responding to the climate emergency requires us to consider ethical aspects of how we will scale up sustainable housing.

Ethical aspects of transitions within the housing domain have not received much attention, but there are opportunities for sustainable housing research to incorporate good governance practices and considerations of poverty, justice, and inclusivity. Tis includes exploring the ongoing question within transitions research around 'who wins, who loses, how and why' [110, 111]. In the race towards a more sustainable future, we need to ensure that social aspects of socio-technical dimensions are not forgotten. Tis means that a more sustainable future must also be just [112]. For our defnition of ethical aspects, we drew on the work by Barrett et al. [113] work on ethical cities which argues we need to integrate climate action, good governance, and action on inequality to achieve ethical outcomes. From this perspective, ethics shape both process and outcomes related to sustainable housing.

#### **6.11.1 Half a House**

In 2016, Chilean architect Alejandro Aravena won the Pritzker prize for his afordable housing concept of providing people with half a house.18 Aravena's practice, Elemental, was commissioned to design 100 houses with a budget of US\$7500 per house (including land, materials, and construction). Tis amount would normally fnance houses that are ~30 square metres, whereas the average middle class family in Chile lives with 80 square metres. Rather than build small single-storey houses, Aravena proposed building 'half a house' of two to three storeys. Te idea was to build good structures with basics such as plumbing for a kitchen and bathroom and core shelter, while leaving the other half of the house incomplete for the households to fnish as their individual resources and circumstances allowed. Tese half houses are also robust and built to withstand earthquakes and other disasters. Rather than just being a house, the half a house is a tool to escape poverty for the households. Once families moved into their houses the unfnished concrete cubes quickly transformed into diferent spaces that refected the needs and skills of the household. As we have stated earlier in the book, shelter is a basic need, and good quality housing provides many benefts including increased health and well-being for the inhabitants. Aravena's approach to afordable housing centres ethics and equity, as well as the environment, with the overall aim of increasing the capacity of the households.

# **6.12 Conclusion**

In this chapter, we explored ten important socio-technical dimensions that we feel will play an important role in delivering the required sustainable housing future. Tese dimensions build upon earlier sustainable housing transitions research undertaken by scholars around the world over the past two decades. However, we have expanded on these to account for current context and recent/future changes across the housing and sustainability markets. We have defned each dimension and

<sup>18</sup>https://bit.ly/3H0Vg9v

discussed how it was viewed within the wider transitions literature; we have explored how the current regime is operating related to that dimension and highlighted the opportunities that sustainable housing ofers in engaging with the dimension. For each dimension, we have provided a short example to demonstrate how these dimensions are playing out in innovative ways. We explore these socio-technical dimensions in more detail across in-depth case studies in Chap. 7.

#### **References**


*the UK.* Proceedings of the Institution of Civil Engineers-Management, Procurement and Law, 2022. **40**: p. 1–7.


**Open Access** Tis chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence and indicate if changes were made.

Te images or other third party material in this chapter are included in the chapter's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

# **7**

# **Sustainable Housing in Practice**

# **7.1 Introduction**

Across the opening chapters of this book, we discussed the importance of needing an urgent transition to a sustainable housing future from environmental, social, and fnancial perspectives. We also explored the current provision of housing and the disconnect between that and where we are required to be for a low carbon and equitable future. Despite the mounting evidence around the benefts of sustainable housing, we still face several challenges in trying to change the system of housing provision. In Chap. 5, we discussed the potential for a sustainability transitions framing to help address some of these ongoing challenges and to help scale up and accelerate the provision of sustainable housing. We identifed ten core socio-technical dimensions from previous research and our own refections, which were presented in Chap. 6 along with short examples of these dimensions playing out in the sustainable housing space.

In this chapter, we explore these socio-technical dimensions in more detail through key themes we have introduced throughout this book: high performing housing, small housing, shared housing, neighbourhoodscale housing, circular housing, and innovative fnancing for housing. Trough these themes, we address sustainable housing at diferent scales as per our discussion in Chap. 3: the dwelling scale, neighbourhood and city scale, and the state, national and international scale. In this way we hope to demonstrate diferent elements and approaches to providing sustainable housing, and indeed, sustainable communities more broadly.

For each theme, we present an overview of and examples of how the theme addresses the diferent socio-technical dimensions. We then present real-life case studies of where the theme is being demonstrated in practice, again referring to the socio-technical dimensions. We have selected these cases based on our own understandings and knowledge, but there are many other equally promising cases we could have included and many of the case studies we selected could have ft within various themes. Our intent is to show how key ideas from the book are translating into the current provision of sustainable housing and demonstrating elements already being provided for what could be the basis of a sustainable housing transition. In each section, we use the key terminology of the socio-technical dimensions as presented in the summary table (Table 7.1).

# **7.2 High Performing Housing**

Te type of sustainable housing we have described in this book provides signifcantly improved performance outcomes compared to the current provision of the majority of new and existing dwellings across a number of dimensions. Importantly, the *physical attributes, knowledge,* 1 and *everyday life and practice* considerations go beyond the current and previous focus on improving energy performance for heating and cooling loads and takes a more holistic view of the dwelling's impact across the whole of its design, construction, use, and end of life phases. In this way, consideration is given to all *physical attributes* (elements) within a dwelling, such as the impact of material choices, and the way the dwelling can enhance liveability outcomes. It is clear from the wider evidence

<sup>1</sup> In this chapter we highlight where socio-technical dimensions are being addressed using the terminology from Table 7.1 and italicizing the terms to make it clear where each dimension is being discussed.


**Table 7.1** Summary of the socio-technical dimensions the themes engage with

Shaded box indicates the theme demonstrates that socio-technical dimension

*(knowledge)* from diferent locations around the world that sustainable housing can be zero energy and carbon across its design, construction, and use, and also provide housing which has zero operational costs to run and which can signifcantly improve health and well-being outcomes that impact *everyday life and practices* as well as *ethics* of housing [1–4]. Others will no doubt have diferent defnitions of what a sustainable house is, and it almost does not matter how a sustainable house is technically defned if it is centred around the core ideas discussed in this book. We also know that the way we defne sustainable housing (and communities more widely) will continue to shift as we provide more high performance housing and new knowledge, materials, construction practices, and technology innovation shapes and reshapes what sustainable housing is or could be.

Tere are important benefts of moving from incremental performance improvements to signifcant performance improvements. Chief amongst those is that to achieve zero carbon emissions goals by 2050, the residential sector will need to reduce carbon emissions by 90–100% by that time, if not sooner. Tis means changing both the *guiding principles* and *physical attributes* of housing. Terefore, all new housing that is not built to that future standard will need to undergo retrofts at some point in the future which will add further housing costs and require more resources. Furthermore, while there can be some small performance improvements through one-of retroft activities, deep retroft is required to provide signifcant emissions reductions, and also to provide a greater range of benefts for the household such as reducing operating costs and improve health and well-being outcomes [4–8]. Tere are also a number of wider benefts beyond housing that could be achieved through signifcant improvements to the performance of housing, including reducing energy generation requirements at a network scale (*geography*).

We are not going to attempt to list all the *physical attributes* and *knowledge* considerations for providing a high performance house; such considerations will depend on a range of factors including local climatic conditions, local materials, the make-up of the wider energy grid (if there is one), whether the dwelling is new or retroftting an existing dwelling, and the scale (e.g., individual dwelling or neighbourhood/city) [3, 9]. Experts in diferent jurisdictions will be able to guide the specifcs for the best options in each context, but there are some broad rules of thumb that are largely relevant across the world. For new homes, *physical attributes* and *knowledge* include:


• Inclusion of renewable energy generation, battery storage, smart appliances, and electric vehicles

For existing homes, *physical attributes* and *knowledge* include:


As discussed earlier in the book, there are a number of formal and informal ways to provide signifcantly improved performance outcomes in housing. One of these approaches is the Passive House (or Passivhaus in German) standard that has emerged in recent decades as one of the most rigorous dwelling standards. Passive House demonstrates diferent *guiding principles, physical attributes, knowledge, industrial structures and organizations, everyday life and practices, culture, civil society, and social movements, and ethical aspects*. Below, we introduce and discuss the standard and present two cases demonstrating where this has been applied and what benefts were achieved.

Passive House is a voluntary low energy building standard that was developed in Germany in the late 1980s [10]. Since this time, over 25,000 dwellings have been certifed to the standard, with more than 100,000 additional non-certifed dwellings estimated to have been constructed following these principles. Te increasing numbers of Passive Houses highlights how they are setting new *guiding principles* and requirements for *physical attributes,* and starting a *social movement* [10]. Te majority of these buildings are in Central Europe; however, there are increasing numbers of buildings around the world which meet the Passive House standard, including in the USA, Canada, and Australia which demonstrates change in *geography*. Te aim (*guiding principles* and *knowledge*) of Passive


**Table 7.2** Performance targets for a European climate for Passive House performance for new dwellings and retroft [adapted from 10]

House is to achieve an energy efcient, thermally comfortable, and afordable house. To be certifed to the Passive House standard, a building must meet the following *physical attribute* criteria (Table 7.2), adjusted based on the country and climate zone.

#### **7.2.1 Erneley Close—United Kingdom**

Erneley Close is a social housing development in Manchester (UK) that underwent a retroft to EnerPHit Standard in 2015. Te project involved the owner (One Manchester) (*markets, users, and power*) undertaking a retroft of 32 two-bedroom walk-up fats for a cost of £3.1 m. Te *guiding principles* for the project were to reduce living costs, and improve health and well-being outcomes for the occupants, as well as initiate wider regeneration of the area [11]. As David Power (Chief Executive, One Manchester) said "…the reason why we've done this scheme is about creating long-term value for the neighbourhood and setting a standard for an area which needs wider regeneration" [12].

In terms of technical performance and *physical attributes*, there was a signifcant improvement in overall performance. Research that monitored the performance of the refurbished dwellings found that they

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performed signifcantly better than typical dwellings, with more stable indoor air temperatures and a reduction in the use of heating and cooling technologies [11]. For example, space heating demand reduced from 300 + kWh/m2 /yr to 23 kWh/m2 /yr and air tightness reduced from more than 10 air changes per hour (at 50 Pascals) to 0.8 [13]. Tis contributed to a reduction in energy costs for households, with tenants reporting savings of up to £100 a month. As one tenant refected:

Before all these works my fat was freezing. I was spending about £15 per week on heating the fat and even using fan heaters to get the temperature up. Since moving back in December, I've only used the heating once. It's really taken the pressure of, knowing we won't be spending an arm and a leg on keeping the house warm, day in, day out. More than that though, everyone here is just so proud of what's come out of this project—it's really put Erneley Close and Longsight on the map. Tere's a real community spirit here now … My little grandson calls the building 'Nanny's castle' because he says it's magical. [14]

Te *ethical aspects* of the Erneley Close high performance housing were not only related to lower energy costs and a reduction in energy for heating and cooling. Tere was a signifcant uplift in community value and pride in the area—benefts that went beyond the individual dwelling [11]. Additionally, tenants reported that their health and well-being improved. For example, several tenants spoke about having lower stress due to reduced energy bills and one tenant reported reduced asthma symptoms. Another tenant stated their child was sleeping signifcantly better due to the quietness in the dwelling from the improved building envelop. Tis quietness also helped the child with their concentration while studying, potentially leading to better academic outcomes.

#### **7.2.2 Whistler Housing Authority Employee Housing—Canada**

Te Whistler Housing Authority (WHA) is a municipal owned corporation in British Columbia (Canada). WHA oversees the development administration and management of resident restricted housing in Whistler. Its aim is for at least 75% of employees to be housed locally through both rental and ownership opportunities that are afordable for local income earners and retirees in perpetuity. As a resort municipality, Whistler struggles more than most with housing afordability. In 2022, the municipality completed the Whistler Housing Needs Report (mandated by the provincial government) and one of the more signifcant fndings was that close to 90% of Whistler's workforce could not aford market housing rates within the municipality [15].

Completed in 2018, the WHA Passive House Employee Apartments is a 24 rental unit, multi-unit residential building [16]. Te project is a collaboration between Integra Architecture, BC Passive House, and WHA, representing stakeholders within both the *industrial structures and organizations* and *markets, users, and power* dimensions of housing. Te building meets Passive House standards and it was designed and constructed using a prefabrication system. Te *physical attributes* of the building included the use of ofsite modular construction, a panelling system, and simple massing. Tese helped to reduce costs and increase productivity, as well as increase energy efciency. In addition, the building was designed with an entry canopy and exterior shading devices, elements that are critical to the building's performance by providing solar shading to avoid unnecessary heat gains and improve occupant comfort. As the building has an extremely low life cycle cost for heating, cooling, and overall electricity, the WHA can maintain it at a lower cost which translates to lower rents for local employees. Tis beneft is particularly important for organizations like WHA that both develop and manage residential buildings. Finally, a unique "Whistler" element to the building is that it was designed with bicycle circulation in mind to support the residents' *everyday life and practices*—bicycles can enter, exit, and be stored easily within the building.

# **7.3 Small Housing**

Te size of a dwelling is related to various factors, including location, culture, and costs [17]. How much space one person, or a family, occupies varies across the world [18]. In Australia and the USA, the average size of a house is around 2500 sq. ft. (240 sq. mt.) [19, 20], which is the largest global average size. However, the size of houses in these countries was not always this big [18]. In the 1950s in Australia, the average house was approximately 1075 sq. ft. (100 sq. mt.), meaning sizes have more than doubled. At the same time, the average number of people living in each house has declined [21]. Larger houses consume more resources and require more energy for heating and cooling. In terms of *physical attributes*, they need more materials for building and maintenance, and need more energy to manufacture and replace any materials or technologies. Larger houses also require more land; while this may be obvious, it is signifcant because larger houses and lots translate to lower densities. Density is an important consideration from a *geography* perspective, including access to transit, jobs, services, and other amenities. Many lowdensity neighbourhoods are car dependent which further increases the environmental impact of larger houses. Finally, low density developments contribute to non-communicable disease risk factors such as physical inactivity, social isolation, unhealthy diets, and poor air quality [22]. And yet, large single-family houses in low density neighbourhoods are embedded within the culture of certain jurisdictions (e.g., Australia), as well as institutional and legal structures [23].

While "the Anglophone ex-colonies of the United Kingdom, such as Australia, the United States and Canada, are characterized by suburban sprawl, mostly large detached houses with a big backyard" [24, p. 299], small dwellings are the norm in most parts of the world, including Asia, Africa, and Europe. Perhaps surprisingly (or not), the regions with the largest houses are where we also fnd a growing tiny house movement although, the movement has taken hold in some European countries including France, Germany, and the Netherlands [25]. Tis movement refers to all housing typologies with a smaller footprint and is often connected to the *guiding principles* and *everyday life and practices* of minimalism and living with less. Many credit the movement's roots to Henry David Toreau, nineteenth-Century US naturalist and essayist, and his call for simple living in natural settings and divestment from material dependence. As an example of *culture, civil society, and social movements*, the tiny house movement has amassed a large internet following through social media accounts, blogs/websites, and YouTube channels, as well as a growing number of documentaries and TV series.

Small housing is frequently claimed to be more environmentally sustainable than conventional sized dwellings [17, 24, 25]. Tis is primarily due to the scale and *physical attributes* as they use fewer resources. Others argue that living in small housing fosters more sustainable behaviours. In fact, *guiding principles* of environmental sustainability is identifed as a strong motivator for many who choose to live small [26]. Some research has found that residents of small housing are more likely to use public transport if they are in urban areas, and for residents in more rural areas, there is an increase in renewable energy use and rainwater harvesting [25]. Less material resources translates to fnancial savings for small housing homeowners. Based on Rawlinsons Australian Construction handbook, in 2016 each additional square metre of brick-veneer house in the state of Victoria cost an average of AU\$1245 extra for construction. Stephan and Crawford [27] calculated that, when combined with heating, cooling, and lighting energy bills over 50 years, the total cost per square metre is higher at around AU\$2000.

Another element of small housing is the potential for density, which is a *geography* dimension. As the world's urban population continues to grow, many cities are looking for ways to incorporate more households within existing built-up areas. Densifcation or urban consolidation involves increasing or maintaining the density of housing in established residential areas. Tere are numerous ways to achieve this goal with more common ones including height and infll. Height primarily refers to apartment buildings built to medium (gross of ~20–40 dwellings per hectare) or higher densities (gross of more than 40 dwellings per hectare). Height allows for dwellings to be stacked, meaning they use less land than single-detached housing. And, while not always the case, apartments are often smaller than single-detached housing. Infll housing generally "fts within" an existing neighbourhood without signifcantly altering its character or appearance. Examples of infll housing include accessory dwelling units (ADU), secondary suites, and missing middle typologies such as duplexes, triplexes, fourplexes, multiplexes, townhouses, row housing, cottage clusters, and courtyard apartments. *Policy, regulation, and governance* and *markets, users, and power* are the primary dimensions related to this type of development and will determine whether developments are permitted (by the government) and accepted by local residents.

#### **7.3.1 Tiny Houses—Globally**

Tiny houses are self-contained dwellings of 400 sq. ft. (37 sq. mt.) or less that can be built on a trailer base and towed by a standard vehicle/truck [24]. Te mobility of tiny houses is mostly due to the *policy, regulation, and governance* surrounding the units. Non-permanent or mobile houses are not recognized or regulated by governments, making it easier to fnd a "parking spot". Tis means that these houses can be located on lots with single family (R1) zoning or on rural properties. Te mobility of tiny houses also makes it necessary (or an opportunity) to have the houses operate of-grid. Many tiny houses have *physical attributes* such as composting or incinerator toilets, exterior water tanks, PV systems with battery storage, and propane/gas tanks (usually for cooking). Besides the gas for cooking, the of-grid elements increase the sustainability of these houses, as does the size of the house itself. Te tiny house movement also has connections to *guiding principles* of the de-growth movement and those seeking to living within planetary means (see Chap. 6). For many, the afordability of tiny houses is the strongest motivation for building or acquiring this type of housing as they are seen as a pathway to home ownership for those unable to get into the traditional market [24]. Tere is a strong do-it-yourself culture associated within the *everyday life and practices* of residents which relates both to environmental and afordability concerns. However, as the popularity of the typology has grown, there are now dedicated tiny house builders for designing and constructing tiny houses. Tis shift is similar to what we fnd within the sustainable housing movement more broadly.

#### **7.3.2 Laneway Houses—Canada**

Laneway houses are a form of detached secondary suites (self-contained dwelling) or ADU built on pre-existing lots.2 Tese units are usually in a backyard with an opening to a lane or street, sometimes replacing a detached car garage. Laneway houses are being used across cities in

<sup>2</sup>https://bit.ly/3B3kiRo

Canada, particularly in Vancouver and Toronto, to create opportunities to increase the number and diversity of rental (and in some cases ownership) units in lower density neighbourhoods. Laneway houses can accommodate a variety of occupants, including multigenerational or multi-family living and more common renter occupants. Placing housing in existing neighbourhoods increases opportunities through *geography* for people to access amenities such as transit, jobs, and services. Te locations and size of laneway houses is dependent on the local *policy, regulation, and governance* such as zoning and bylaws. Te location is related to zoning, where lots need to be zoned R2 or higher (meaning more than one dwelling on the lots). Bylaws will determine some of the *physical attributes*, including the footprint and setback of the unit in relation to the size of the lot and distance between other structures, the height, number of storeys, minimum foor area, minimum room sizes, the orientation, and exterior components such as deck or balcony.

#### **7.3.3 Never Too Small—Globally**

Never Too Small (NTS) is a media company that features small footprint design and living.3 NTS is based in Melbourne, Australia, but showcases small footprint living from around the world. Most of the projects shared are less than 600 sq. ft. (55 sq. mt.), with most being much smaller. Trough their YouTube Channel, Instagram and Facebook accounts, hardcover book, and website, they feature designers and their awardwinning tiny/micro apartments, studio, and self-contained projects. In their book *Never Too Small: Reimagining Small Space Living*, they include the layouts of each of the projects to share *knowledge* and encourage more people to live small. NTS's *guiding principle* is that, through design and creative use of space, we can transform the way we live in cities. Many of the designers from the projects showcased are passionate about supporting more sustainable housing outcomes by being more intentional about the size and location of dwellings and the *physical attributes* used as part of the design and construction.

<sup>3</sup>https://bit.ly/3VIoT3x

#### **7.3.4 600sqftandababy—Canada**

600sqftandababy (600) is a blog and Instagram account chronicling the experience of a family of three, then four (two adults and two children), living in a 600 sq.ft. one-bedroom apartment in Vancouver, BC.4 600 also includes *knowledge* sharing through "Small Home Tours" of other families intentionally living in spaces of ~1000 sq. ft. (93 sq. mt.) or less. By sharing images and stories, the author shares their family's *guiding* principles around doing their best to live small, thoughtfully, and sustainably in an urban context. Tere is a strong focus on living with less not only in terms of square footage, but also when it comes to the "stuf" we put in our homes. While not always explicit in the material, afordability also plays a big role in the choice to live small. As the popularity of the blog (and the concept) grew, the author also began ofering small space design consults. Te aim of 600 is to demonstrate through *everyday life and practices* how a family lives small with the hopes of encouraging others to consider doing the same, as well as ofers a sense of community and confdence to those that already do.

# **7.4 Shared Housing**

For most of human history, people have lived communally. People lived in communities, camps, settlements, villages, or in multigenerational family arrangements where resources and labour were shared or traded. Tis began to change at the onset of the industrial revolution (beginning in the late 1700s), which represents the process of change from an agrarian and handicraft economy to one dominated by industry and machine manufacturing. As industry changed, so did social and political conditions. Famers and artisans moved to cities to become industrial workers in factories and populations began to increase (particularly in cities). By 1800, London was the largest city ever known with nearly 3 million inhabitants. Tenement buildings were built to house the growing populations of workers and their families. While many people lived in the same

<sup>4</sup>https://bit.ly/3ixYKWI

buildings, families lived in individual units and spaces were not shared. Tese buildings were overcrowded and referred to as slums. Tose who could aford better living conditions and larger spaces moved to areas outside of the cities, what we now call the suburbs. Early suburban developments solidifed our understanding of housing nuclear family units within self-contained houses and yards. What began in the UK has shaped the way many people have lived (and continued to live—*everyday life and practices*) in the USA, Canada, Australia, New Zealand, and many parts of Europe. Tese living arrangements were further entrenched in 1900s through the use of *policy, regulations, and governance* mechanisms to enforce separation of land use types, distance between buildings, and minimum sizes of rooms and dwellings.

Te post-war era (1950s) is often referred to as the era of the suburban. While the suburbs were full of promises—peace and prosperity—they also revealed problems within society. Te dispersed nature of suburban developments meant there was an over-separation of uses, lack of activity, privatization of public spaces, reliance on private vehicles, neglect of the inner city, and many were left out (e.g., racialized and queer populations). Te 1960s and 70s saw a backlash in the post-war suburban societies in places like the UK, Europe, and the USA. Communal movements began to take shape where people created communes and cooperatives, squatted in empty or under-utilized buildings, and practised alternatives to economic capitalism. Motivations (*guiding principles*) difered from environmental to spiritual to anti-government, among other ideologies. But, each communal approach represented a radical departure from the nuclear family model. Te communal movement has been experiencing a revival since 2010's. Some of the external factors for this include the impacts of COVID-19 lockdowns, loneliness, the desire for low carbon living, and housing afordability.

Cities, and suburbs, can be isolating places, particularly for those living alone. A 2017 Vancouver Foundation survey found that almost a third of 18–24-year-olds in the region experienced loneliness "almost always" or "often" compared to just 14% of the rest of the population [28]. Housing afordability was identifed as one of the main culprits for making people lonely. In Canada, the 2021 census data revealed that couples with children accounted for 26% of the total population while one-person households represented 30% of the population [29]. For the most part, the *physical attributes* of housing have not necessarily changed at the same pace as the changes in demographics. As mentioned in Sect. 7.2 in the small housing theme, the average house size in places like Canada (as well as locations like Australia and the USA) has increased (as has the price tag). We are seeing more apartments, particularly onebedroom dwellings, but we are missing middle and alternative housing options, such as shared housing.

Buildings, including housing, and neighbourhoods can ofer spaces and opportunities to interact and form communities. One of the *guiding principles* of shared housing is to explicitly create opportunities for encounters and conviviality between residents, as well as promote people to linger through *physical attributes*. Danish urban designer Jan Gehl emphasizes the importance of "life between buildings" as it promotes trust and intercultural and intergenerational tolerance, and it enables people to get to know their neighbours [30]. In shared housing, design is used to provide the conditions for community, but it is through people's *everyday life and practices* that connections are created and held. Tis can be done in intentionally communal spaces such as lobbies and circulation, as well as shared laundry facilities, gardens, rooftop terraces, and other amenities. Tese spaces can also be designed to invite people to linger or incorporate elements such as furniture, information boards, or art displays. In addition to physical interventions, some shared housing has a strong emphasis on selection or self-selection of residents. In some cases, people self-organize to develop shared housing, like Baugruppen in Germany (see Sect. 7.3 for more on this approach). For existing shared housing development, this may be done through application or vetting processes or by limiting residents to owner-occupiers.

Tere are many arguments and claims of greater sustainability and reduced environmental impact for shred housing, when compared to mainstream housing [31]. Tis is often attributed to the *guiding principles* of the developments or residents. Many are drawn to shared housing for environmental reasons, and social interaction with others engaging in pro-environmental *everyday life and practice* can contribute to higher participation across the development or community [32]. In terms of *physical attributes* and *geography*, shared housing can support sustainable housing outcomes. Sharing spaces or facilities (such as laundries) can reduce the size of individual dwellings and minimize the environmental footprint of the development and improve resource efciency [33]. Shared housing ofers opportunities for more efcient use of land through use of space and density. Te scale and communal nature of shared housing can support efective use of resources and waste management practices. Tese include more elaborate composting and recycling programmes; grey water fltration systems; rainwater collection; community scale energy projects; and sharing resources and bulk purchasing [32].

#### **7.4.1 Co-Housing—Globally**

Te concept of co-housing (bofællesskab in Danish) originated in Denmark in the late 1960s, but it is now a global movement (*geography*) [34]. Co-housing developments are self-managed housing clusters that include self-contained dwellings with all the amenities of a typical dwelling (including a kitchen, bathroom, etc.), as well as shared spaces and facilities (*physical attributes*). Tere are no strict rules when it comes to the size or form of the developments. Co-housing developments can include new and existing buildings, attached and detached housing types, diferent types of tenures (owner-occupier, rental, co-operative), diferent numbers of occupants or residents, diferent demographics, and diferent locations (urban, suburban, rural). What is shared across the communities is the belief in creating intentional communities by living with your neighbours, not beside them (*guiding principles*) [35]. In a study of 18 collaborative housing communities in England and Wales conducted in 2020 during the frst wave of COVID-19 lockdowns, researchers found that co-housing dwellers experienced a higher level of support and care than typical households (*ethical aspects and everyday life and practices*) [36]. Co-housing developments are primarily bottom-up initiatives with future residents taking the lead, or at least participating in the design and management of the community (*knowledge*).

Co-housing has been proposed as a response to both the housing afordability and climate crises [37]. As an alternative housing model, it aims to combine "the three pillars of sustainable lifestyles: technical (energy), social (community), and economic (afordability)" [37, p. 66] (*guiding*  *principles*). Measuring the sustainability of co-housing is challenging because there is high variability across developments [38]. However, as residents tend to live in smaller units and share spaces and facilities, they often have a lower footprint. In addition, the value of cultivating an intentional community attracts a lot of people interested in living more sustainable lifestyles (*everyday life and practices*). Te co-housing concept, therefore, has potential to support sustainable housing outcomes.

#### **7.4.2 Nightingale Housing—Australia**

Nightingale Housing, a model that prioritizes shared and sustainable housing, emerged in Melbourne (Australia) in the late 2000s [39, 40]. Tis model was pioneered by architect Jeremy McLeod of Breathe Architecture, in conjunction with a collection of local architects working with the current *industrial structures and organization* of housing who shared a similar goal: to provide higher density housing that properly, and equally, addresses the triple bottom line of sustainability and afordability outcomes. Te *guiding principles* of Nightingale Housing have since evolved and now include sustainability, reductionism, energy efciency, afordability, community, alternative transport, healthy homes, engagement, housing security, resales, Teilhauses (German for "part of house", also known as micro units), community contribution, and reconciliation [41]. While the model started in Melbourne, it has moved to other regions of Australia (*geography*). Trough *knowledge sharing*, there are now 15 completed developments with seven more under construction and another ten upcoming [42]. While the developments go signifcantly beyond minimum construction code performance requirements (e.g., providing a minimum thermal energy load of 68 MJ/m2 /year which is 40% lower than regulated minimum for new housing of 114 MJ/m2 /year in 2022 for the Melbourne climate zone), it is the provision of shared and community spaces that is challenging business-as-usual design in Australia.

Te *physical attributes* of Nightingale Housing follow a reductionist design approach to remove some of the key private elements from individual apartments that are be typical in standard apartment developments in Australia. In particular, a key diference is the removal of individual laundries in favour of a shared laundry located on the roof of developments. Te aim of this approach was to not only save internal space in the apartments, along with associated costs and resources, but to also include a deliberate plan to help foster *culture* and community by providing a place for residents to engage with each other. As McLeod has stated, "when you are doing your washing on the rooftop you quickly meet all your neighbours. Meeting people over washing laundry is a good way to break down barriers pretty fast. After that happens a few times, there are no awkward silences!" [43]. Te rooftops typically include a rooftop garden with space to relax, entertain, and even host events. Again, this reduces the need for private space and opens up opportunities for sharing and community engagement. Other opportunities for sharing within the model include the provision of access to shared cars, although the developments are designed to reduce dependence on cars (e.g., through reduced or eliminating car parking on site). Te ground foor of these developments also typically includes a combination of ofce space and retail/services to activate the street frontage and, again, create vibrant opportunities for engagement for building occupants and the local community. In several cases, the cafes that have been included have *ethical aspects,* as they are social enterprizes, giving an opportunity for work to people who might not have typically had that type of opportunity otherwise.

#### **7.4.3 Three Generation House—Netherlands**

While common before the Second World War, most families in the Netherlands now live in nuclear family homes separated geographically from other generations and family members. Te Tree Generation House, is a single multi-storey building located in *Amsterdam Noord* and designed by BETA Ofce for Architecture and the City, sought to change this paradigm and reconsider multi-generational living (*guiding principles*) [44]. As the name suggests, the house is home to three generations: grandparents, parents, and two children (six people). Te house was completed in 2018, with the younger couple and children living in the city prior to completion and the grandparents living separately in a suburban environment. Te aim of the project was to create a house that ofered all the benefts of shared spaces and living together without sacrifcing privacy. Te *physical attributes* of the house were designed as two separate apartments stacked on top of each other with a shared communal entrance. Circulation throughout the house is possible by having both an elevator and central staircases. Te house is reductionist in terms of aesthetics and, from a sustainability perspective, includes high-grade thermal insulation and triple-glazed windows.

In addition to being designed to accommodate three generations, the house is designed to accommodate changes in *everyday life and practices* and for residents to age in place. Te central circulation allows for future adaptability of foorplates so that studio apartments can be carved out of existing spaces or foor space from one unit can be added to the other. So, as the children age and want their own space, the house can evolve with the family. While the elevator is an obvious inclusion for ageing in place, the grandparents' unit has level foors and wider door openings to accommodate wheelchairs if needed. In the Apple TV show "Home", one of the architects and the father in the family states that he intends to die in the house, emphasizing his belief in both multi-generational living as well as adaptable and universal design principles.

#### **7.5 Neighbourhood-Scale Housing**

When people talk about sustainable housing, the focus is usually on the *physical attributes*. People tend to look to architects, engineers, and builders, but planners, urban designers, and landscape architects, among other professionals, are also involved in housing. As we have made clear throughout the book, there are so many other dimensions that contribute to, and impact, sustainable housing provision and outcomes. When housing is planned and developed at the neighbourhood-scale, there is a lot of government oversight through *policy, regulations, and governance* mechanisms that infuences the result. As discussed in Chap. 2, buildings must be built to the minimum specifcations outlined in building codes, where planning is responsible for approving developments which includes location, type, size, and mix, among other considerations.

Tere is no prescribed defnition of the neighbourhood-scale. Te size or attributes are context specifc. Neighbourhoods can be understood as spatial units that people can relate to; they are places where you can work, live, and have access to shops and services [45]. Neighbourhoods are smaller than cities or towns and are comprized of multiple buildings.5 Te scale is appropriate for both experimentation and impact. From a sustainability perspective, neighbourhoods are often better places to respond to environmental, social, and economic considerations. Working at the neighbourhood-scale, compared to one-of buildings, ofers opportunities to combine resources and coordinate eforts, and to interact with other *institutional structures and organizations* [46]. Examples include district heating and cooling,6 community renewable energy generation and use (*physical attributes*), and shared amenities such as car co-ops and shared outdoor spaces (*everyday life and practices*). Neighbourhood-scale developments also have the ability to incorporate *ethical aspects* by considering housing mix, diversity, and afordability.

Neighbourhood-scale housing is closely tied to urban form and site type (*geography*). Urban form refers to a neighbourhood or city's physical characteristics. It is commonly represented by density, land use types, mix or diversity of land use types, spatial confguration, transport networks, infrastructure networks, and environmental conditions. Site types refers to the status of the land and its surroundings. Tere are generally three common approaches: greenfeld (development land or change of land use), brownfeld (previously developed land), and infll (un(der)development land boarded by developed land). Greenfeld sites are most often found in dispersed (sub)urban forms while brownfeld and infll can be found in a variety of compact urban forms. Tese include smart growth, new urbanism, and the 15-minute city. Smart growth is an approach to development that encourages a mix of building types and uses, diverse housing and transportation options, development within existing

<sup>5</sup>Whittier, Alaska being the exception; most of the town's population lives in one building that includes a school, post ofce, health clinic, store, and other amenities and services.

<sup>6</sup>District heating and cooling is the centralized generation and distribution of heating and cooling. For example, a district heating network allows many individual consumers to access heat that has been produced from multiple sources, such as combined heat and power, large scale heat pumps, municipal waste incineration, biomass boilers, or industrial waste heat recovery.

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neighbourhoods, and community engagement. New urbanism is based on principles of "traditional" cities and towns where housing is located within walkable communities, near shopping and public spaces. Te 15-minute city is more of an idea or goal where everyone can meet their essential needs within a 15-minute walk or bicycle ride [47]. At the core of these forums is the connection between density and diversity. Density refers to the number of dwellings in a particular area while diversity refers to the mix of housing typologies as we add other building types and land uses.

Te compact urban forms mentioned above represent diferent approaches that can be adapted to diferent locations and contexts. Tere are also rating tools that have been developed to "certify" developments that focus on specifc outcomes and use formalized rating schemes. In 2007, the U.S. Green Building Council (USGBC) worked with the Congress for New Urbanism and Natural Resources Defense Council to develop LEED for Neighborhood Development (ND) [48]. Tis collaboration brought together key stakeholders from the *market, users, and power* dimension. Te impetus for the new LEED classifcation was the recognition of the importance of cities and neighbourhood-scale responses to climate change. Individual building and dwellings cannot be separated from their surroundings. Te aim of LEED ND was to encourage community planning processes to support "green" innovation and transformation [49]. Te LEED ND rating system comprizes two adaptations: LEED ND: Plan and LEED ND: Built Project, which have certifcation options unique to this rating system. Like all LEED programmes, neighbourhoods can achieve one of four levels of certifcation: certifed, silver, gold, or platinum. Tere are fve categories for LEED ND: smart location and linkage, neighbourhood pattern and design, green infrastructure and buildings, innovation, and regional priority. Each category has several prerequisites and credit components. Te credits are then calculated to determine the level of certifcation. For example, for smart location and linkage, agricultural land conservation and foodplain avoidance are prerequisites while access to quality transit and steep slope protection are credit options.

#### **7.5.1 Dockside Green—Canada**

Dockside Green (DSG) is a residential neighbourhood spanning 15 acres along the harbour near downtown Victoria, BC.7 DSG is a brownfeld redevelopment (*geography*) that incorporates Smart Growth principles, LEED ND Platinum certifcation, building reuse, economic development, and environmental regeneration. Prior to redevelopment, the land was used for shipping and shipbuilding, timber processes, an oil refnery, and an asphalt plant. All of this left a heavily contaminated shoreline with vacant buildings. Te parcels of land that now make up DSG were purchased by the City of Victoria for \$1 in 1989 and in 2002, an environmental assessment commissioned by the City concluded the land could be developed. A detailed development concept was completed in 2004 after extensive public consultation which established the *policies, regulations, and governance* approaches for the development. Later that year, the City issued a request for proposals to remediate and redevelop a large portion of the site. Windmill Developments won the bid and selected Busby Pekins+Will as the architects due to their *knowledge* with LEED buildings. A large portion of the fnancing came from VanCity, one of Canada's largest credit unions, who also became a co-developer of the project. DSG also received funds from the federal and provincial governments.

Inspired by BedZED in the UK (see Chap. 6), the *guiding principles* for DSG were to imbed a triple bottom line approach to sustainability by building one of North America's most innovative neighbourhoods and be a model for sustainable development. Te *physical attributes* of the development itself are comprized of LEED Platinum buildings, a wastewater treatment plant, a biomass plant, electricity metres, efcient appliances, reclaimed materials, car co-op memberships, and other amenities. Te master plan includes 26 buildings (75% residential) with the development divided into 12 phases. Construction began in 2006 with Phase 1 of the project being completed in 2008 and Phase 2 in 2009. DSG has won numerous awards, both locally and internationally, including the 2006 Smart Growth BC award, the 2008 GLOBE Awards for

<sup>7</sup>https://bit.ly/3UmFCs1

Environmental Excellence, and Top Ten Green Projects from the American Institute of Architects/Committee on the Environment in 2009. Although, major criticisms of the early development were its lack of afordability as the focus was on environmental sustainability and many of the systems and technologies incorporated into the designs were very expensive at the time. After this, construction would pause for over 12 years, initially due to the global fnancial crisis (*markets, users, and power*) and then because the land and development rights were sold to Bosa Properties. As of 2022, the next phase of the development is for sale.

#### **7.5.2 White Gum Valley—Australia**

White Gum Valley (WGV) is a residential development of approximately 80 dwellings on an area of 2.13 ha in a middle ring suburb of Perth, Western Australia. Te development is located 20 km from Perth and 3kms from the City of Fremantle. Te site was previously home to a school which closed in 2008. WGV includes 23 single dwelling lots, 4 larger lots for multi-dwelling units, and a "Generation Y" demonstration housing lot [50]. Te *physical attributes* of the project have been designed to allow all homes to integrate passive solar design principles and other sustainability initiatives. Te range of lot sizes and confgurations provides opportunities for housing diversity and a range of price points, specifcally to support trends towards smaller households for singles, couples, and seniors. Te development aims to have an operationally net zero carbon impact on the natural environment and applies the *guiding principles* of the "One Planet Living" framework (see Chap. 6).

Beyond improved performance at an individual dwelling level, the development addresses sustainability across the neighbourhood (*geography*) through water sensitive urban design (e.g., passively irrigated trees and landscapes, communal bore water access, landscaped infltration basin and onsite storm water retention systems [51]), improving biodiversity outcomes, transport, cultural development, housing afordability and access, and food sourcing [52]. Tere is a focus on *ethical aspects* through a range of dwelling types, afordable housing typologies and rental/ownership options, and on reducing residents' costs for energy and water [53]. Te neighbourhood scale of the project is also considered in the community scale battery storage system and the peer-to-peer renewable energy-trading scheme. Te WGV project is structured within multiple policy frameworks including the City of Fremantle's Local Planning Policy 3.15 [54] and the project specifc WGV Design Guidelines published by Landcorp WA [52].

### **7.6 Circular Housing**

Globally, the residential sector contributes around 17% of total greenhouse gas emissions and consumes around 19% of total energy demand [55, 56]. Additionally, the housing sector consumes 30–50% of raw and recycled materials for new housing and retroftting of existing housing [57]. Te impact from materials is not only in the construction phase, but also through the generation of waste during construction, throughlife (maintenance), and at end of life. While specifc data for the residential sector is limited, it has been estimated that an average of 1.68 kg of construction and demolition waste is produced per person per day from the wider construction sector [58] of which the majority is not reused or recycled [59]. Te total amount of materials consumed across the construction sector is growing at an increasing rate annually [59, 60].

To ensure that the residential sector contributes to a broader sustainable future, new and existing housing will need to signifcantly reduce its environmental impacts across all phases of a dwellings life by addressing *physical attributes, knowledge*, and *everyday life and practices*. Tis includes not only reducing energy and water consumption by occupants, but also through reducing impacts from materials, ensuring we use signifcantly less raw materials in our construction and maintenance of housing, and designing for deconstruction and reuse at end of life. Te idea of the circular economy has emerged in recent decades as a framework that challenges the current linear business-as-usual practices of industries (i.e., extract materials, use materials, dispose of materials as waste) [61]. It has been estimated that a circular economy could address *physical attributes,* such as through reducing CO2 emissions from building materials by 39% in 2050 [62]. Te circular economy framework, which encompasses both *guiding principles* and *knowledge* dimensions, has been increasingly applied by policy makers and businesses (*industrial structures and organizations, markets, users, and power,* and *policy, regulations, and governance*) to a variety of industries, including the residential sector [46, 63].

Tere is no universally agreed upon defnition for circular economy [64]. Geissdoerfer et al. [65, p. 759] describes the circular economy "as a regenerative system in which resource inputs, waste, emissions, and energy leakage are minimized by slowing, closing, and narrowing material and energy loops. Tis can be achieved through long-lasting design, maintenance, repair, reuse, remanufacturing, refurbishing, and recycling". However, as others point out, this type of typical circular economy defnition does not really engage with social and temporal dimensions or specify other key ideas pertinent for the circular economy (e.g., design for disassembly and reuse and optimizing of sharing which are important in the context of the built environment) [66, 67].

We defne circular housing as housing that is produced and consumed utilizing closed loop principles (*guiding principles*), prioritizes local employment (*industrial structures and organizations*), achieves resilient and functional design, provides carbon neutral/energy efcient and regenerative operation (*physical attributes*), and enhances value across the design, construction use, and end of life phases of a dwelling. Circular housing promotes afordable, accessible, ft-for-purpose housing (*markets, users and power*) that is appropriately located (*geography*) so that it addresses social, economic, and intergenerational equity concerns (*ethical aspects*). Tis can be provided across various scales from the individual dwelling to across a community or city-level (*knowledge*). Tis leads to a more resilient material supply chain and creates value and opportunities for a range of existing and new businesses involved with the construction sector.

To some degree, new and retroftted sustainable housing already leans into many of these ideas. However, the circular framing takes these outcomes further by having an increased focus on designing and using materials in a way that not only improves sustainability outcomes but also ensures that we design for deconstructions and reuse of materials at end of life, signifcantly improving *physical attribute* outcomes [68]. Circular housing is emerging in diferent jurisdictions around the world (*geography*), driven by *policy, regulations, and governance* stakeholders [46, 64]. Europe, in particular, has been an early leader in the circular economy and housing space, both for new housing and retroftting of existing housing. Several other jurisdictions such as China and Japan and cities such as Paris and Amsterdam have implemented a range of circular economy strategies, including across the built environment and residential sectors [66, 69]. Table 7.3 highlights some elements that are being provided within a circular housing framing.

A core *guiding principle* within the circular housing framing is to design for disassembly/deconstruction and reuse as a starting point. In doing this, end of life value can be enhanced but it does require the *knowledge* to work backwards to maximize such outcomes. In the UK, BRE (Building Research Establishment) [70] undertook an analysis of design for disassembly of various types of housing. Teir analysis showed a variance across


**Table 7.3** Examples of circular housing principles in practice across dwelling to neighbourhood scales. Table adapted from [46, 69]

housing types and identifed signifcant opportunity to improve circular housing outcomes, such as design for disassembly. For one example, a traditional 3–4-bedroom brick house on a concrete foundation from a large builder, the analysis calculated a reuse and recycling potential score of 49%, an optimization of deconstruction score of 86%, and an overall design for disassembly potential of 61%. Elements such as internal fnishes could largely be removed by hand to reduce damage to the structure and other large building components such as windows, roofng, and framing could be removed with typical machinery (e.g., excavators or cranes).

#### **7.6.1 Circle House—Denmark**

Tere are examples of housing emerging that are designed, from the start, to follow principles of circular economy including design for disassembly. One such example is Circle House in Denmark that consists of 60 social housing units in the city of Aarhus [71]. Te residential typologies are a mix of two- and three-storey terraced houses and fve-storey tower blocks. In terms of *physical* attributes, the housing is built from the same six concrete elements to ensure not only quick construction time but that more than 90% of its materials can be disassembled and reused at a high value. Te use of Gyproc Ergolight system walling is an example of a material that not only reduces CO2 emissions compared to conventional plasterboard walls by 45% but allows for 90% of the material to be reused at end of life without having to crush it down and recycle it into new boards [71]. Te Circular House project also engaged with other *guiding principle*s of the circular economy, including signifcantly reduced environmental impact and improved quality and durability [71]. Te development also aimed to drive new business models, partnerships, and innovation to help change the wider housing *industrial structures and organizations* [71].

#### **7.6.2 SUPERLOCAL—Netherlands**

SUPERLOCAL is located in the Dutch municipality of Kerkrade. Te project was conceived as a response to a number of socio-economic challenges in the local region including a rapidly declining population and unsuitable housing [46]. Te site of the project contained four ten-storey apartment buildings that had been built during the 1960's and were no longer ft for purpose [72]. After demolishing one of the buildings and sending the waste to landfll, it was recognized that this approach was not suitable for a range of reasons, including impact on the local community [46]. In 2014, the project was repositioned to engage with circular economy *guiding principles*. Tis meant regenerating the existing housing stock and renewing the wider neighbourhood. In terms of *physical attributes*, the project aimed to achieve a greater than 90% reuse of building materials and products from existing buildings for any new construction [46]. Tere was also a focus on providing on-site solar generation, a closed water cycle, and reducing car use.

Te project also included *ethical aspects* such as a strong focus on providing improved social outcomes, including spaces for the community to meet and interact and a range of new afordable social housing for rent and purchase. Some of the new housing was constructed with material waste from previous buildings and designed to be easy to disassemble so that materials could be reused at the end of life. Sustainable materials were also used across the development, with footpaths and cycling paths using recycled concrete from waste out of existing buildings on site. Te project has won several awards for the use of sustainable building materials, building systems, and innovation, including the Dutch "Building Prize" (Nederlandse Bouwprijs) in the category building materials and building systems in 2019. In 2021, the project was awarded the title of "Deserving City" from the Guangzhou International Award for Urban Innovation.

#### **7.6.3 Cape Paterson Ecovillage—Australia**

Te Cape Paterson Ecovillage is located on the outskirts of Cape Paterson, a rural town 120 km south-east of Melbourne (Australia). Te project was conceived in the early 2000's with construction starting in 2013 and expected to be completed around 2024 [73]. When completed, there will be 230 detached homes, a small number of short-stay accommodation dwellings, a conference centre with a café, a community building/education centre, and a community urban farm. Around 50% of the site will be open space, and the project has already revegetated more than 440,000 native plants to enhance the local natural environment [73, 74].

Te *guiding principles* of the development are focused on maximizing environmental and social sustainability within a longer time frame (100 years+), both at an individual dwelling level and across the development. For the *physical attributes*, the developer created a set of design guidelines that have provided high performance housing, such as setting minimum thermal energy performance and renewable energy generation requirements that go signifcantly beyond minimum regulatory requirements [74]. To ensure these requirements are met, all house plans need to go through a design review process with a panel of sustainability and design experts. Various stakeholders (*industrial structures and organizations*) involved in the design and construction of housing on the site have worked with various material suppliers to improve sustainability outcomes, focusing on reducing waste during construction, reducing the need for maintenance during the life of the dwelling, and improving design for disassembly outcomes [46].

Ideas of circularity in this development go beyond just the dwelling and extend to providing a more sustainable community, especially with considerations for the social outcomes. For example, in terms of *everyday life and practices*, the large community farm on site aims to provide a range of sustainability benefts including reducing food miles, healthier eating, opportunity for selling produce, and providing a system to compost waste products created on site [75]. Further benefts are not just limited to the development site. A key outcome for this development is *knowledge* sharing, with a range of house designs freely available on the development's website, free for anyone to download and use.

#### **7.7 Innovative Financing for Housing**

As discussed earlier in this book, the real and perceived fnancial cost for providing improved sustainability continues to be a challenge that contributes to the slow uptake of sustainable housing and sustainable communities more broadly. Tis relates mostly to capital costs, but also in some cases to the ongoing costs (e.g., maintenance) of sustainability inclusions. Te challenge of perceived higher fnancial costs persists despite an increasing amount of evidence (*knowledge*) from research and real case studies demonstrating that the performance of existing housing can be signifcantly improved through low cost measures (*physical attributes, knowledge*) and that new high performance housing (see Sect. 7.1) can be provided for little, if any, additional cost compared to traditional new dwellings (*markets, users, and power*). However, there continues to be some research and wider discourse which suggests that the costs for sustainable housing could still be anywhere from 10–100% higher than minimum regulatory requirements. Tis conficting information creates confusion, not only for consumers, but also for policy makers, the industry, and even researchers!

Te question of fnancial costs for sustainable housing is complex and needs to be addressed. *Policy, regulation, and governance* responses to providing sustainability have often relied on the wider market to determine the value for sustainability outcomes (see Chaps. 2, 3, and 4 for more on this). However, there have been market failures that mean consumers either do not value sustainability, are unable to aford it, or do not understand it, especially within the context of the climate emergency. For example, sustainability elements for housing have often been portrayed by larger regime actors as "add ons" to base designs, which are seen as increasing costs. However, costs for housing are made up of many elements and there are a range of opportunities to address costs during the design and construction of new housing and through the design and retroft of existing housing, but also through the fnancing of this work at the household and industry level.

For example, *physical attributes* such as good design and improved consideration and use of materials should be able to improve the overall thermal performance of a dwelling. In this case, if any heating and cooling technology is included, it can be smaller as the house will require less input to maintain thermally comfortable indoor temperatures in many locations. Good design should also improve functionality of a dwelling and reduce wasted space. Tis is important if we are to address the large house sizes that have emerged in some locations, and the *markets, users, and power* associated with those houses. However, not everything can be designed out. Te addition of *physical attributes* like renewable energy generation and storage is something that will have a cost attached to it. Importantly, with low provision of sustainable housing (new and retroft), costs will likely be higher due to limited stakeholders in that space who are able to do the work, and also because cost efciencies from economies of scale will not yet be realized across current *industrial structures and organizations*. Te cost reduction for solar PV, which have fallen by 96% between 2000 and 2020, is one example of the opportunity available to reduce costs for sustainable housing across the full construction cycle [76]. So, the question of impact on capital costs is a balance between the savings from reduced costs in some areas with potential costs in others. What we see is an emerging number of case studies in various jurisdictions that demonstrate that sustainable housing can be provided for low additional costs, but more is required to provide assistance in relation to addressing the issue of fnance.

As there are increasing housing afordability and cost of living challenges in many regions, anything that is perceived to add costs to the construction and purchasing of a dwelling is seen as something that can be done without to ensure we are making housing more afordable for everyone. Tere are several issues with this premise. Chief amongst those is that sustainability is provided on top of base house costs, rather than thinking about the design and costs as a holistic approach. It also focuses on the capital cost (i.e., the price tag) rather than factoring in the throughlife costs of the dwelling. Even if a sustainable house costs more upfront, the *ethical aspects* of reduced living costs, improved occupant health and well-being, and wider social, fnancial, and environmental benefts have been, time and again, shown to outweigh any initial costs [2, 7, 77–80]. Additionally, most people who buy a dwelling do so through borrowing money from a fnancial institution. Tis means that any additional cost is not strictly something that needs to be paid for upfront. Research has shown that improved performance can often ofset any impact on additional mortgage repayments and can lead to mortgages being paid of years earlier, saving the household tens of thousands of dollars in interest [77–79].

In an attempt to create a more level playing feld and provide a "protected space" for sustainability niches to develop and position themselves to challenge the existing housing regime and market, there has been an increasing use of various fnancial mechanisms. Perhaps the most widely implemented example across the world has been the use of fnancial rebates or subsidies through *policy, regulations, and governance* to help reduce the capital cost of installing solar PV (and other renewable technologies). Tis is typically provided by governments who see this as a way to make certain sustainability technologies more afordable and to help drive uptake. Te aim being that, as a greater number of households take up the sustainability technology, the market (*industrial structures and organizations)* will build, driving down costs to a level where government assistance is not required. Governments may ofer a rebate which decreases over a period of time to reward early adopters but also to factor in that costs should decline for households over time. Te rapid uptake of residential solar PV in Australia from the mid 2000's is an example of where this type of fnancial innovation, along with generous feed-in-tarifs, has helped drive signifcant change within the *markets, users, and power* dimension [81]. Battery storage and electric vehicles are also seeing similar fnancial assistance in many regions. However, this type of fnancial innovation is not without critique, with concerns about access and equity being raised about such approaches [82–85].

In recent years, a range of fnancial innovation has developed around the world and there has been an increasing number of key actors (including those from both the *industrial structures and organizations* and *markets, users, and power* dimensions) involved in developing and providing innovative fnance and trying to shape markets. No longer is this just the domain of governments, but increasingly fnancial institutions, organizations and others are becoming involved. Tere has also been a shift in how fnance and value are considered, through *culture, civil society, and social movements*, moving to through-life considerations (given the long life of a dwelling), and also better engaging with wider social, environmental, and fnancial value [79]. Below, we explore some of these examples to give an understanding of what is occurring and what is possible.

#### **7.7.1 Baugruppen—Germany**

Baugruppen—German for "building group"—is a self-developed afordable urban co-housing model that emerged in Germany in the 1990s. Tis model changes the stakeholders normally found within the *markets, users, and power* dimension of housing. By having a housing community come together to collaboratively engage in the design, construction, and use of housing within a Baugruppen development, a number of process efciencies can be achieved which results in a reduction in the cost of the housing by 10–30% [86]. For example, having the community commit to owning a dwelling in the community prior to the start of construction can avoid the need for real estate agents, marketing campaigns, and the construction of display suits, as well as wider opportunities for shared amenity [87]. Additionally, the collective of households acts as the developer, reducing the need for developer profts [86]. Baugruppen can be any type of housing, but has largely been provided in multi-storey, multifamily buildings [87]. Tis model has now spread beyond Germany with examples in locations like North America and Australia (*geography*).

#### **7.7.2 Green Mortgages—Globally**

Green mortgages have emerged in recent decades as an approach within the *markets, users, and power* dimension for individual households or developers to address the issues related to the costs of sustainable houses [88, 89]. Tere are diferences to how these are structured across diferent jurisdictions or companies, but there are common elements to the base intent. For a green mortgage, the lender will ofer a reduced interest rate for a dwelling that has gone beyond minimum regulatory requirements (e.g., for thermal performance of base building and/or for the inclusion of sustainability technologies—*physical attributes*). Tis reduced rate might be for a period of time or the entirety of the home loan. Tere are also variances on this where the lender may allow for greater borrowing capacity knowing the living costs will be lower [90]. Te intent is that it will encourage households to include more sustainability elements with the knowledge that any additional costs will be ofset by lower mortgage repayment rates. For the lender, they are reducing the risk of missed loan payments or defaulting on loans as the evidence fnds that those who are in more sustainable housing are a lower mortgage risk [79]. A variance on this might be to pause mortgage repayments for a set period of time (e.g., 2 years) to allow the household to save and pay for sustainable upgrades.

#### **7.7.3 Rebates and Subsidies—Globally**

As noted above, rebates and subsidies have been used by various governments as *policy, regulation, and governance* mechanisms to help incentivize households or the wider market to provide improved outcomes. Tis has often been in the form of a direct reduction in the cost of a particular sustainability technology or material, as well as through providing a fnancial rebate directly to the household or supplier once the sustainability activity has been implemented. Typically, these types of approaches will ofer a certain percentage of the cost calculated based on what the government feels is a balance between providing fnancial assistance while still having some consumer buy-in. Some jurisdictions are going beyond this approach. In Italy, there is a superbonus 110% scheme that entitles households who do certain retroft and quality upgrade improvements to a tax credit of up to 110% of the cost of the work [91]. Since the scheme launched in July 2020 as part of the country's post-pandemic recovery strategy, more than €21bn of funds have been paid out for more than 120,000 approved applications. However, this type of programme comes with its own sets of challenges related to fraud, problems of governance, and implementation [92].

# **7.8 Conclusion**

Tis chapter has attempted to demonstrates both real world case studies across key themes of the book and the socio-technical dimensions required for change (see Chaps. 5 and 6). What is clear from these cases is that there is a lot of amazing sustainable housing work being provided around the world and this should give us all hope that a transition to sustainable housing is not only possible, but also that we have the means to be doing things right now. However, the cases also show that, even with these leading examples, there is still room for improvement. Tese cases have also largely been one-of examples. We need to fnd ways to scale up these examples and accelerate the transition to a sustainable housing future. In the following chapters, we refect on what we have covered in the book so far and discuss what this means moving forward.

#### **References**


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# **8**

# **Facilitating the Sustainable Housing Transition**

# **8.1 Introduction**

Te evidence makes it clear that the way we are currently providing housing is not sustainable from a range of perspectives. As discussed in the early chapters of this book, current housing provision has a signifcant impact on the environment, and we need to facilitate a sustainable housing transition if we are to achieve wider emission reduction targets. However, such a transition is not just about reducing the environmental impacts of the housing sector, but also enhancing social and fnancial outcomes for individual households and our wider society. In those earlier chapters, we discussed the challenges and opportunities we currently face to facilitate this sustainable housing transition. Given these challenges, and the complexities across a range of socio-political-industrial elements, the middle chapters explore the idea of sustainability transitions as an opportunity to address these challenges and help with the accelerated provision of sustainable housing at scale, in both the new housing and existing housing spaces. Te previous two chapters explored how this was being addressed in real world examples and case studies across ten diferent socio-technical dimensions and across key themes identifed in earlier chapters of the book.

In this chapter, we draw upon the preceding chapters to discuss the implications of the evidence and current context for facilitating the sustainable housing transition. We do this across three core sections. In Sect. 8.2, we discuss the importance of drawing upon sustainability transitions theory to inform the sustainable housing transitions. Tis includes refections on how we need to extend the theory to align with the unique challenges of the housing sector. Following this, Sect. 8.3 focuses on the sustainable housing transition, including where we are placed in that transition, potential pathways forward, and challenges that still need to be addressed. In Sect. 8.4, we refect on the types of innovations required across policy, practice, and research to help facilitate the sustainable housing transition. We then build upon this in Chap. 9 by discussing the prospects for a sustainable housing transition and revisiting the core ideas woven throughout the book.

## **8.2 Sustainable Housing Transitions: Beyond a Niche**

Within broader discussions of urban sustainability transitions, housing has long been identifed as a niche [1–4]. In part, this has emerged from an understanding that a transition to a low carbon housing future will require more than just a technical solution, and in fact, will require deep structural changes to the way housing is provided and used [5–8]. However, analysis of housing as a niche has been problematic. Housing design, technology, location, quality, performance, and afordability have signifcant implications for households' health and well-being, liveability, costs, fnancial gain, and access to jobs, services, and recreation [9–29]. Housing intersects across diferent housing typologies and characteristics (e.g., new and existing housing), scales, time, and sectors. Te idea of a 'niche' as it is typically applied within transitions research does not capture this kind of complexity.

Much of sustainable housing transitions research comes back to the early work of Smith [1, 30]. Smith explored the development of sustainable housing niches and defned the current regime through a socio-technical (or sustainability) transitions framework. Tis research made an important contribution towards developing an understanding of the contrasting socio-technical dimensions of, and current pressures between, niche actors and the regime. Much has changed in the sustainable housing space since Smith's work, not only in terms of technological innovation but also in relation to improved understandings of the social implications of housing. In addition, sustainability transitions research has evolved with several new areas of focus being put forward to improve understandings and implementation of transitions [31]. We argue it is time to re-visit how we look at housing within sustainability transitions and refect on how we might approach housing transitions research differently given recent theory and sustainable housing developments.

To do this, we focus on socio-technical dimensions, rather than the niche-regime dynamics of housing. Socio-technical systems are multiactor processes that consist of multiple elements, such as practices, policies, or technologies. In Chap. 6 we presented 10 socio-technical dimensions for sustainable housing transitions: (1) guiding principles, (2) physical attributes, (3) knowledge, (4) geography, (5) industrial structures and organizations, (6) policy, regulations, and governance, (7) markets, users, and power, (8) everyday life and practices, (9) culture, civil society, and social movements, and (10) ethical aspects. Each dimension begins with a defnition followed by an overview of how the current housing regime engages with the dimension and how sustainable housing ofers a diferent approach, ending with a short example of how this is being provided or considered in practice. In Chap. 7, we explored how these socio-technical dimensions intersect across diferent housing typologies and characteristics, scales, time, and sectors. We organized this around six themes: high performing housing, small housing, shared housing, neighbourhood scale housing, circular housing, and innovative fnancing for housing. Each theme begins with an overview and is followed by a series of case studies. Te aim is to demonstrate ideas from the book in real world projects.

When we evaluate sustainable housing through these socio-technical dimensions, it is clear that there have been some signifcant changes within the sustainable housing space. For example, in relation to industrial structure and organizations, sustainable housing has shifted from bespoke single buildings with a cost premium to scaling up the delivery of multiple buildings and even whole precincts with little, if any, cost premiums. In addition, new research directions highlight the need to consider ethical aspects within current governance approaches to the sustainable housing transition. Focusing on socio-technical dimensions demonstrates that sustainable housing delivery is not only occurring within the traditional housing industry but with input across other sectors such as energy networks (e.g., with renewable energy generation and battery storage) and transportation (e.g., public transport and electric vehicles). Tere is also a 'messiness' occurring with diferent speeds of progress (e.g., new vs existing housing). Te outcome is that housing is not well suited to being considered as a niche from a traditional transitions perspective. Without a rethink of housing, the sustainable housing transition cannot truly challenge these deeper structural changes within the current housing regime.

# **8.3 Facilitating the Transition**

If we use wider climate change target goals of achieving near zero emissions outcomes by 2050 as a starting point for change in the housing sector, we have less than three decades to transition to the type of sustainable housing we are advocating for in this book. While this may seem like quite a long time, the reality is that it is not long at all. Looking at policy development around the world, we see that in places like the EU and California it took at least 10 years from the announcement to implementation of zero (or near zero) energy/carbon new housing [32, 33]. Tese approaches included various step changes1 at intermittent periods to have a controlled improvement to minimum performance requirements. If other jurisdictions were to take action today, it is likely that we would not see all new housing achieve the standard required for a low carbon future until at least 2035. And that would assume that policies could be

<sup>1</sup>We defne step changes in policy as where there is a longer term policy goal set e.g., 10 years, with smaller 'step change' policy identifed at various points across the specifed time period to help shift the policy and outcomes from where they currently are to the longer term goal.

developed and approved quickly, but as this book has explored, nothing is ever easy when it comes to implementing or improving minimum building performance requirements. We must also recognize that not all countries even have minimum performance requirements which means it may take them longer to frst introduce and then improve standards to the level required. Looking at other jurisdictions, it has taken 30–50 years to go from the introduction of some minimum performance or sustainability standards to the point they may be close to delivering the types of housing required [34–36]. We simply do not have the time now to wait for other jurisdictions to take the same type of pathway.

In recent years, we have seen sustainable housing policy attention broaden from new housing to existing housing. In some jurisdictions, there has been the introduction of minimum performance requirements for existing housing. Tis is typically being applied at the point of sale or lease of a property, where the dwelling must ensure it meets a minimum standard. While a good step forward for ensuring improved performance of existing housing, there are some limitations to this approach. For instance, there is often a ceiling for how much money the dwelling owner must spend on improving performance (which could potentially mean not lifting performance sufciently to meet new standards if retroft activities hit the fnance cap frst), and it is only dwellings on the market for rent or purchase that are being captured (missing most existing housing). Additionally, the requirements for improving quality and performance are generally about incremental improvements, and there is a signifcant gap between that and what we are advocating for in this book. Te existing housing sector is likely several years behind the new housing sector in terms of achieving or requiring quality and performance outcomes for new housing. Te challenge remains that it can be more difcult to improve the quality and performance of existing housing due to existing dwelling characteristics and constraints, and not all dwellings will be able to cost-efciently achieve the types of performance outcomes that new housing can (or will at the very least require diferent approaches such as the use of more technology).

Clearly there is a disconnect between the current provision of housing and where we need to be for a low carbon future [4, 35, 37]. Tere is also a signifcant gap between leading jurisdictions and their requirements for new and existing housing, and what is being provided in the housing sector in other jurisdictions. Tis highlights the need for diferent approaches in diferent jurisdictions.

If we go back to the sustainability transitions phases presented in Chap. 5, the sustainable housing transition is still in the pre-development phase (see Fig. 8.1). Tere is limited visible change at the systems level, but substantial experimentation and development are occurring at the niche level with pressure for change starting to build on the current regime in some jurisdictions. Perhaps, in some jurisdictions with more advanced minimum performance regulations, it could be argued that they are entering the take-of phase where enough pressure is being exerted on the existing regime and the niche challenger is beginning to destabilize the regime and increase its own difusion. However, the evidence presented in this book suggests that most jurisdictions are frmly in the pre-development phase of this sustainable housing transition.

**Fig. 8.1** The MLP and interactions between the three nested hierarchical levels with our refection of where we are in the sustainable housing transition and where we need to transition to

Te question is, how do we facilitate the sustainable housing transition to move from that pre-development phase through to take-of, and then into the acceleration and fnally stabilization phases?

It would be nice to think consumers and the wider housing sector will naturally start to demand and provide sustainable housing at the levels required, within the timeframe required. However, we have limited confdence that this will be the case given the complexities of housing markets and the way they have been structured. What will be required is a proactive push and pull approach where various policy levers and industry innovations are used to signifcantly improve the quality and performance of housing and support deep structural changes to the housing industry. Tis will require a clear pathway that maps out the changes needed over the coming years and decades. To ensure a well-considered approach, any pathway should be developed working backwards from longer term goals and timeframes (e.g., sustainable housing by 2050) and forwards from where we currently are. For example, in Australia more than 8 million dwellings will need to be retroftted by 2050 meaning that 35 dwellings per hour need to be retroftted. However, capacity to start delivering this outcome is not available—it needs to be scaled up frst. Developing a plan around this scaling up is not just about the number of houses or labour required, but also about supporting supply chains and other industries that are involved.

Based on the evidence of housing regulation development, and the urgency of change required, all jurisdictions should be introducing sustainable housing requirements in accordance with the material in this book by no later than 2030. For this to be successful, jurisdictions need policy pathway plans to determine how to get from where they are now to the targeted 2030 outcome as soon as possible. Tis will provide transparency and give confdence to the housing industry, other stakeholders, and housing consumers, as well as provide time for the industry to adapt. Te policy pathway can also act as a framework for those in the housing industry who want to innovate and go beyond minimum requirements. Tis will help create a market advantage, drive innovation of design and construction, and work to reduce any costs from the required changes. For those jurisdictions further advanced with their minimum housing quality and performance requirements, they could be aiming to achieve these outcomes even sooner.

Te existing housing sector is more complicated than new housing due to reasons discussed earlier in this book. However, the ambition should be to see the majority of existing housing achieve sustainable housing performance outcomes of at least 80% of those of new housing in terms of improving performance through various approaches such as improving insulation and glazing, and updating to energy and water efcient appliances and including renewable energy technologies. Tis is what wider research says is possible and should be the minimum target for existing housing [38–44]. Many stakeholders have argued we should frst focus on improving new housing outcomes to get them right before addressing existing housing, but there is more potential to rapidly improve the sustainability outcomes of housing from the existing housing sector. Terefore, we should be ambitious with pathways for addressing existing housing performance. By 2025, there should be a requirement for mandatory disclosure of building quality and performance at point of sale or lease that includes cost efective opportunities for upgrade and retroft. To ensure confdence, this information must be robust, reliable, and transparent.

With this mandatory disclosure information in place, jurisdictions should look to introduce minimum performance requirements that are triggered when a dwelling is sold or rented. Using examples from Europe, this approach would frst look to capture the worst performing housing (e.g., F and G on the A–G scale) and improve them to a higher standard (e.g., to a minimum of E), targeting the most cost-efcient retroft opportunities. Following this, there should be a clear plan to improve minimum requirements to higher performance levels across a defned time period so that there is a clear pathway for change. If the above is in place by 2025, it would not be unreasonable to expect that minimum performance requirements could be improved from E in 2025 to D in 2028, C in 2031, and B in 2034 (allowing for 3 years in between minimum performance changes). From 2035 onwards, requirements for existing housing at point of sale or lease could be aligned with new housing requirements. Although, some fexibility would be required to accommodate that not all existing housing will be able to achieve the same outcomes in the same ways, and may require alternative solutions (e.g., if there is no capacity for onsite renewable energy generation, it may need to be located ofsite). Tat would mean there is 15 years from 2035–2050 to retroft all existing housing to the level required for a low carbon future. Some jurisdictions are starting at a higher level for quality and performance of existing housing and should be able to mobilize and scale up deep retroft earlier, potentially achieving sustainable housing outcomes for all existing housing by 2040 (or sooner). Tis more ambitious timeline will help inform and guide other jurisdictions that are further back on their sustainable housing transition, and should not be used as a reason for those laggards to delay improvements, as each jurisdiction must take individual action as part of the global collective.

Te above is naturally a broad plan and each jurisdiction would need to develop a specifc plan based upon local context, capacity, and skills. However, given that the issue of mitigating climate change is a global challenge, we should look for at least some level of coordination for the sustainable housing transition. Tis means that there should be global pathways that set expected practices, with some fexibility for jurisdictions to adapt as required. Any pathways must include sufcient policy, industry, and consumer support, and take place at diferent levels. Globally, there is a need for a coordinated approach, and this must start by bringing together jurisdictions to work through a process to develop and implement a shared global plan, similar to the Conference of the Parties conference events. Every jurisdiction should develop short, medium, and long term goals for improving housing quality and performance, goals that should be linked to wider climate change and other societal targets.

Setting longer term policy is a critical step towards the sustainable housing transition [36]. However, this will only be successful if there is sufcient support in place to allow the transition to occur. Tis support needs to include education for the existing regime and housing consumers, and potentially fnancial support to help ofset any additional costs from improved performance requirements. If fnancial support is to be provided (e.g., through rebates for sustainable materials or technologies), these should be a clear phase-out plan so there is an incentive for stakeholders to innovate and drive down costs. Tere are also challenges around the globe with a lack of labour and supply chain issues. Tese will also need to be addressed to ensure that we can scale up the sustainable housing transition without delays or choke points in the system. Governments should also provide support for further research and development of retroft solutions that can be delivered at scale and across different housing types. Tis could open opportunities for retrofts to be delivered to a greater number of dwellings more quickly, more efciently, and at a lower cost, rather than addressing retrofts one dwelling at a time.

Improving performance of new or existing housing at the individual dwelling level is important, but it is not the only focus in the sustainable housing transition. To fully unlock the potential of the sustainable housing transition, we need to have housing stakeholders engage with stakeholders in other related sectors such as energy and transport. Te energy network in many countries has been developed as a centralized system whereby energy is generated at fossil fuel generation plants and transported large distances to the places where energy is used. Te move away from fossil fuel energy, and the balance between the scaling up of dwelling and larger scale renewable energy generation, should provide the opportunity for innovations in the energy network to help facilitate the sustainable housing transition. For example, decentralized energy networks could help share renewable energy between neighbouring houses. Te role of electric vehicles and the development of two-way batteries in these vehicles also open up diferent opportunities for energy management at a dwelling level.

While this book has largely been focussed on developed countries, a global sustainable housing transition must include developing countries. Te housing challenges in developing countries are often diferent to those in developed countries, and we must ensure that the sustainable housing transition in developing countries can help address some of those wider housing and social challenges in those locations. Much like with the global climate change approach, we will need developed countries to help support developing countries with the sustainable housing transition. Tis can be through sharing of knowledge, skills, materials, technologies, and research, but also likely through fnancial support to help such countries change their housing industries.

#### **8.4 A Time for Refection**

In the previous section, we outlined pathways to facilitate the sustainable housing transition for new and existing housing. Tis was largely a pragmatic exercise working through a visualization and back casting process to map out a pathway for how we can achieve a sustainable housing transition by 2050. Tis process was focussed on regulatory and policy changes to drive the transition as this has been found to be the most successful way for improving minimum quality and performance outcomes across the housing sector. As such, the pathway takes an overarching view of the transition and assumes that more nuanced changes at various levels under the policies (e.g., changes to construction practices) will also be included.

Furthermore, there is no discussion in the above pathway around the type of housing we are providing or if it is sufcient for our housing needs today and into the future (not just from a quality and performance perspective, but in terms of the characteristics of our housing). Tere is a need to challenge wider considerations of housing to ensure we are not just bolting on sustainability to existing ideas of what housing is. Instead, we need to take this opportunity to reconceptualize housing and housing needs. In many housing markets, consumers have been provided with housing based on what the housing sector has deemed consumers want. We need to ask if this is really what consumers want, and we need to provide them with information about their choices and encourage them to explore alternative options. Te opportunity to reconceptualize housing should be done within the wider social, fnancial, and environmental challenges seen across the housing sector.

For example, afordable housing issues are increasingly prevalent in many jurisdictions [45–47]. Exploring opportunities to address sustainable housing could also help address afordability issues [4, 48, 49]. Some of the case studies we presented in Chap. 7 highlight how this can occur. Co-housing and Nightingale Housing are two alternative ways to provide housing where elements of a traditional house are shared, helping to reduce environmental impact and construction costs. To provide this type of housing at a larger scale, it is not just about changes in the design and construction process but will also require households to let go of their perceptions of what should be included within a dwelling. Changing social understandings of housing and housing needs will be necessary if we are to successfully facilitate a sustainable housing transition.

We also need to encourage a range of stakeholders to think in a more visionary way to unlock diferent ways to reconceptualize housing and help create diferent options across the housing sector. It is interesting to look at TV shows or movies set in the future and see how they are providing housing. Are there lessons we can learn from those imagined futures to help us with our sustainable housing transition?

It is not just imagined futures that can help us reconceptualize housing. Climate scientists are telling us with increasing certainty what the changes to the climate will be into the not-so-distant future. We need to use this information to inform the provision of climate resilient housing moving forward. Tere are multiple elements to this, including that we need to use climate projections to inform the design of our new housing and retroft of our existing housing. As we noted in earlier chapters, the evidence is already showing that the performance of housing is changing with the climate. We must use climate data from at least the midpoint of the assumed life of a dwelling to ensure that the performance is suitable for that climatic future.

We also need to use this information to ensure we stop building in locations that are at higher risk of climatic events in the future. Tis will mean that areas we have already built in, or are expanding into, may not be suitable for communities to live in as our climate changes. Increasing fre, food, and other climatic events in recent years have exposed poor planning of housing, and there is already an impact on households, the wider community, and governments. For example, in Australia in 2022, repeated foods in a region of New South Wales led the state government to announce a buyback programme for up to 2000 dwellings as the risk of exposure and damage to further food events was deemed too signifcant [50]. Tere are going to be increasing examples of this around the world where whole communities may have to be relocated due to climate change impacts. Who will pay for this, and how will decisions be made about who is moved (and to where), and who is excluded from any move? Tese are questions most policy makers and society have not had to ask, but it is important we start asking now.

Additionally, we need to ensure that the sustainable housing transition does not just occur for those who can aford to participate, but that everyone is included. Te evidence fnds that vulnerable households face a range of fnancial, social, health, and well-being impacts from the housing they live in, and that they are often living in poor quality and performing housing [48]. It is critical that there is a focus on how to ensure vulnerable housing cohorts are included, if not prioritized, in this sustainable housing transition. Tis will likely require diferent approaches and collaborations to help vulnerable households compared to what approaches might work for the wider housing community. To help facilitate this, there needs to be a shift in considering housing from an upfront capital cost to the through-life impact of housing on households (and the wider environment and society). For example, including health and wellbeing benefts in the considerations of policy changes will ensure that improved value is not just about the fnancial bottom line, but about wider impacts [51].

Troughout this book, we have acknowledged that we are in a climate emergency and, as such, need to urgently address the quality and performance of housing. Time is of the essence in relation to wider environmental impact, but also increasingly due to the rising cost of living and other emerging social impacts related to our current housing. In Sect. 8.3, we mapped out what we believe to be a realistic but pressing pathway that will require signifcantly quicker progress for many jurisdictions. However, while the sustainable housing transition is time sensitive, we must ensure we do not create unintended consequences by moving too quickly. In this regard, our pathway above sets out short-medium term policy actions to ensure a scaling up of the provision of sustainable housing, and to give clear guidance to the wider housing industry and consumers about what will change and when the change will occur. Tis will help ensure everyone is working towards the change.

A challenge with scaling up sustainable housing quickly will be ensuring that such housing is actually provided and that shortcuts are not taken. Tis will require rigorous checks and balances throughout the design and construction (or retroft) process to give consumers confdence that what they are paying for is what is provided. Te disconnect between design intent and actual performance is already an issue in many jurisdictions and must be addressed moving forward [35]. Tis will mean a higher number of random checks by independent experts throughout the construction process, as well as stronger legal protection for households. In many countries, there is a lack of opportunity for consumers to seek redress for housing that fails to meet expected standards of quality and performance.

Innovation will also be important the help facilitate the sustainable housing transition. Technology innovation has been a signifcant area of focus within the wider housing sector over recent decades, but there is a need for more innovation across all phases of a dwelling from the design through to end of life. Tis innovation is not just for physical attributes like materials and technologies, but also the processes involved for providing housing. Troughout earlier chapters, we have noted a number of innovations being attempted in the planning system that are trying to fnd ways to improve the provision of sustainable housing, such as through encouraging higher density housing in suitable locations. However, there are opportunities for other innovations or the expansion of existing mechanisms and approaches, which could help address some of the challenges we discuss in this book. For example, upfront cost and a lack of hands-on experience have been raised by some in the residential construction industry as holding back the provision of sustainable housing.

Inclusionary zoning is a planning mechanism that requires a certain percentage of housing provided in a development to be set aside for afordable housing. Tis approach is used in some jurisdictions and it helps to provide more housing that is afordable to those who typically could not aford such housing. A similar approach is being used to require developments to be built to a signifcantly higher standard compared to regulated minimums through green building re-zoning processes. Increasing the use of these types of policies would help to give those in the housing construction industry incentive and experience building to a higher standard (helping to negate the lack of experience challenge) and would help provide more sustainable houses (helping to address cost challenges).

We need to fnd ways to bring together a range of diferent stakeholders and expertize to think about innovations that could help facilitate the sustainable housing transition. It will be by working together than we can ensure this transition is as efective and efcient as possible.

## **8.5 Conclusion**

Te evidence presented in this book makes it clear we need a sustainable housing transition. Earlier chapters presented sustainability transitions theory as a useful framework for helping to understand and facilitate such a transition. However, as we explored in this chapter, the sustainable housing transition will require us to extend this theory and our understanding of how to apply the theory in practice. In extending the theory, there are a number of practical outcomes that will be required to facilitate the transition. For example, we must come up with global and local plans for how this sustainable housing transition can occur. Having a global approach will allow a collective and shared response to the issue of housing quality and performance and ensure that efciencies are maximized through global supply chains. With varied local housing contexts and diferent starting points, each jurisdiction will need to adapt this global plan to ensure we can efciently and efectively deliver upon the sustainable housing transition. As we discuss in this chapter, we must also take the opportunity to ask key questions of our housing and housing needs.

## **References**


*Cooling and Heating from South Australia.* Housing, Teory and Society, 2019: p. 1–21.


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# **9**

# **Prospects for a Sustainable Housing Transition**

## **9.1 Introduction**

By this stage of the book, it should be clear that housing is critical for our society for a range of reasons. Housing primarily provides us with a place to shelter from the elements and gives households their own private space, and the provision of adequate housing is a basic human right. Te UN states that adequate housing must address security of tenure, availability of services, materials, facilities and infrastructure, afordability, habitability, accessibility, location, and cultural adequacy [1]. Many of these basic housing requirements can be addressed through the provision of sustainable housing, as we have described in earlier chapters. Given the climate emergency and wider social challenges related to housing, we believe that environmental and social sustainability considerations of housing must be included within the basic elements of housing promoted by the UN.

Despite knowing the importance of housing, there are signifcant environmental, social, and fnancial issues with the current provision of housing in many jurisdictions [2–8]. Current housing has a signifcant negative environmental impact, it is making people sick, and it is increasingly unafordable to own, rent, and live in [9–19]. Globally, we have an increasing number of examples (see Chaps. 6 and 7) where the type of sustainable housing we are advocating for in this book is already being provided, for both new and existing housing and at diferent scales and through diferent approaches. While not all examples are perfect, they demonstrate that we can be doing signifcantly more right now. Tere is no need to wait for more technological innovation, for design knowledge, or for evidence of performance to provide sustainable housing; we just need to get on with doing it.

In this fnal chapter, we revisit the core ideas woven throughout the book. We summarize the current situation and how the current provision of housing will not meet our environmental or societal needs moving forward. Despite the mounting evidence of the benefts of sustainable housing, we still face key challenges that need to be urgently addressed to ensure we can deliver a sustainable housing transition that includes everyone. We discuss the prospects for change and explore where that change needs to occur. We fnish the chapter with some concluding refections.

## **9.2 Sustainable Housing: Current Context, Future Challenges**

Following decades of fragmented or limited action on climate change, we are in the middle of a climate emergency [20, 21]. Already, we are experiencing the impacts of a changing climate on our built environment. For example, there is an increase in the frequency and severity of extreme weather events (e.g., heatwaves) and disasters (e.g., fres, foods), and this is predicted to get worse moving forward [20, 22]. Te consensus among climate and environment scientists is that we will need to reduce our global emissions by 80% or more by 2050 to mitigate catastrophic climate change [20, 21]. Our individual and collective response to this climate emergency will shape our short-term future and have impacts for future generations.

However, in relation to environmental sustainability, it is more than just needing to signifcantly reduce carbon emissions. We have known for more than 50 years that we were not sustainably consuming resources and we have been consuming non-renewable resources at a rate faster than they can be regenerated [23]. Recent data suggests that we are consuming our earth's resources at the rate of 1.75 planets per year and there is limited evidence that this is changing any time soon [24]. Clearly, we are not living within the means of our one planet and have not taken the signifcant steps required to address this, despite the plethora of warnings for what is likely to occur should we not heed these warnings and respond to them.

Tere has been some promising global progress in recent years towards addressing climate change and other environmental and societal challenges. UN Climate Change Conferences of the Parties in 2021 and 2022 moved the global discussion forward with agreements for more stringent and urgent action. However, there are many sustainability advocates who argue these recent agreements do not go far enough given the current climate emergency. Te UN's Sustainable Development Goals are another global initiative and have also helped focus attention on delivering key improvements across their 17 goal areas [25]. However, as researchers and other advocates have argued, incremental policy and practice change is not sufcient for addressing the climate emergency; we need to do much more across a shorter timespan if we are to avoid the most catastrophic of climate change outcomes [3, 26, 27].

Te housing sector has a critical role to play in delivering a more sustainable future. Globally, the housing sector contributes around 17% of total greenhouse gas emissions and consumes around 19% of total energy demand [3, 28]. Additionally, the housing sector consumes 30–50% of raw and recycled materials for building new housing and retroftting existing housing [29]. Te impact from materials occurs through the use of materials and the generation of waste during construction, throughlife (maintenance), and at end of life. Given that housing is a long-life infrastructure, any transition to a low carbon future must include sustainable housing.

In this book, we defne sustainable housing as dwellings with a zero carbon impact that, where possible, contribute to regeneration initiatives that support wider sustainability. Sustainable housing is housing that signifcantly reduces its life cycle impacts and engages with concepts of the circular economy (e.g., design for disassembly). However, it is more than just physical elements; sustainable housing improves health and well-being, reduces living costs, and connects to other sectors such as transport, food, and energy networks. Sustainable housing draws on a variety of design, material, technology, and construction innovations to build housing that will perform well now and into the future. Tis is not just performance from a technical perspective, but also in terms of resiliency against a changing climate (e.g., resilient to extreme weather events).

Sustainable housing is about more than just reducing environmental impact. It is about addressing a range of wider social and fnancial issues across the housing sector in many regions of the world. Housing is imperative to meet our basic human needs [1] and should provide us with safe, secure places to live, and improve social outcomes like health and wellbeing. Despite this, we continue to see challenges with the provision of adequate housing around the world. For example, more than 1 billion people live in slums or informal settlements, and more than 100 million people are estimated to be without homes entirely [30]. Tere are also signifcant housing afordability issues for many who do have access to housing, with the cost of purchasing and renting increasing at a faster rate than incomes in many jurisdictions over recent decades [6]. As a result, housing is precarious for a growing percentage of the population and this is being exacerbated by rising cost of living (e.g., costs for energy).

It is not just the provision of housing that is important. Research demonstrates that good design, quality, and performance can improve a range of outcomes for households including improving their health and wellbeing, reducing living costs, and adding resale value, in addition to reducing environmental impacts [31–35]. Conversely, poor design, quality, and performance have been found to negatively impact these outcomes [2, 7, 11, 15, 17, 18, 34, 36–40]. When replicated at a larger scale, the benefts go beyond individual dwellings to the wider community. For example, the use of vegetation can help improve thermal performance of a single dwelling, but large-scale urban greening can help reduce air temperatures in heatwaves by 15 °C or more [41–44]. Tis not only helps make our climate more comfortable, but it also reduces the need for mechanical heating and cooling and reduces health and mortality outcomes.

While each climate zone has nuances in terms of how to deliver sustainable housing, the evidence from around the world shows there are some broad rules we should all be following [45–47]. Tese relate to new housing, but many are also relevant for existing housing. At the individual dwelling level, this includes (but is not limited to):


Despite the benefts of sustainable housing, only a small percentage of the current housing market achieves design, quality, and performance outcomes in line with what is required for a low carbon future [4]. Tis low uptake points to signifcant neo-classical market failures. Te current housing regime operates on the idea that sustainable housing can be left to the wider consumer market to drive demand and create competition, innovation, and cost efciency. Tis idea has been widely criticized and been shown to not deliver the type of outcomes needed at the speed required. However, there is a small section of the market that is using information about dwelling design, quality, and performance to improve decision making, with emerging research suggesting a tangible fnancial value for more sustainable houses. Energy Performance Certifcates used throughout Europe and elsewhere are an example of this information provision, although at this stage, the speed of consumer change does not match what is required to deliver a low carbon future [48].

To address these market failures, governments around the world have typically used minimum design, quality, and performance requirements by way of regulations [49, 50]. Tese regulations have arguably had signifcant success in raising the design, quality, and performance of the bottom of the market, but generally fall short of what is required for a low carbon future. According to the IEA, only around 85 countries have mandatory or voluntary building codes with specifc energy requirements, highlighting the challenge in introducing these [4]. Other issues are evident such as ensuring regulations are enforced, as well as the implication of minimum standards being good, rather than being the legally mandated bare minimum. However, leading jurisdictions like the EU and California have introduced a range of advanced regulatory requirements in recent years and now require all new housing to be delivered to a performance level near our defnition of sustainable housing [51, 52]. In locations where mandatory requirements are not adequate, or where none exist, the use of voluntary standards like Passive House and Living Building Challenge ofer a framework to provide signifcantly higher design, quality, and performance [53, 54]. Unfortunately, there are many in the wider housing industry who push back against the need for improved regulations or changes through planning systems, saying that such changes add red tape and ultimately add costs to consumers. However, as the evidence and case studies presented in this book indicate, we are now able to provide sustainable housing for little, if any, additional costs for consumers.

Another important lever in the provision of sustainable housing is the use of planning systems. Before a dwelling or community is constructed, land use planning has a critical role to play in terms of determining the ease of delivering improved outcomes for sustainable housing [55–57]. For example, if vacant housing lots are planned to optimize dwelling performance, it can result in signifcant improvement to thermal performance and/or reduce the costs for achieving higher standards. Statutory planning can facilitate other elements related to sustainable housing, such as where housing is located, the types of housing in an area, and considerations of general or specifc amenities.

Tere has also been an increasing use of alternative mechanisms to help address wider market failures and drive the provision of sustainable housing. Examples include consumer education about energy and water efciency, product labelling programmes, rebates, and tax incentives or subsidies for sustainability technologies or building practices.

A number of challenges are prevalent with the provision of standard housing. Once a dwelling is constructed, the performance and environmental impact has been locked in for many decades. Tis means it is critical that we ensure all new housing meets much higher standards. To do this we need to focus on the design stage, where the old rule of thumb estimates that around 80% of a dwelling's impacts are locked in during the frst 20% of the design process. Failure to ensure new housing performs to a higher standard means that much of housing not yet built will likely need to undergo expensive retrofts. Research from around the world calculates that it could cost approximately £20,000 or more to provide deep retroft [58, 59].

New housing is almost the easier housing type to address. With new housing, there are less constraints and more opportunities to provide much more signifcant outcomes when they are designed in from conception. Addressing the existing housing stock is more challenging. An existing dwelling has a range of constraints that may limit what opportunities are possible to improve sustainability outcomes. If we are to achieve a low or zero carbon housing stock by 2050 (at the latest), it will require signifcant action on existing housing [2, 3, 59].

Another challenge is how to account for housing and household trends. For example, in some jurisdictions, there has been an increase in the foor area of dwellings over time [60]. Tis increase in foor area has been found to ofset increases in energy efciency requirements and has occurred while the average number of people per dwelling has been decreasing. Additionally, this increase in foor area means we have more stuf in our homes, further creating complexities in how we provide sustainable housing. Te way we use our homes is changing, which can impact the performance of a dwelling. For example, during COVID-19, many people were required to work from home (where possible) despite many dwellings not being designed for such a situation [61, 62]. Tis created challenges for liveability (e.g., shared work/living spaces with no boundaries between areas) and performance (e.g., at home for more hours therefore consuming more energy for work activities as well as things like heating and cooling).

Scale is also important for understanding and providing sustainable housing, particularly the dwelling scale, neighbourhood and city scale, and state, national, and international scale. Tis is because each scale presents diferent opportunities to provide sustainable housing, and we need to leverage these diferent scales to ensure optimal outcomes are delivered. For example:


# **9.3 Prospects for Deep Structural Change**

Troughout this book, we have highlighted the signifcant challenges limiting the scaling up of the provision of sustainable housing around the world. As touched on in Sect. 9.2, there are various factors contributing to this. What the current context and wider evidence suggests is that, in order to provide sustainable housing at the scale required, we need to challenge the current provision of housing and the existing housing regime. In doing so, we can create deep structural change across the housing sector and the entrenched resistant stakeholders. Building upon the work of other sustainability transitions researchers, we argue that there are ten key socio-technical dimensions that must be addressed if we are to achieve a sustainable housing transition [63]. Tese socio-technical dimensions are:


We have provided numerous case studies in Chaps. 6 and 7 that demonstrate how these socio-technical dimensions are already being addressed in real world, sustainable housing projects. Tese case studies demonstrate what is possible. While we do not argue that all these case studies are perfect, they do ofer signifcant insights into how we are (and can) already be providing housing that is much more sustainable. Te case studies provide us with an opportunity to move the sustainable housing transition from the pre-development phase, through to the take-of phase, ultimately leading to an acceleration phase, and then stabilization of a new sustainable housing regime. Tese case studies, and our refection of sustainability transition theory, extend recent research exploring the sustainable housing transition and how to facilitate the scaling up of solutions [27, 31, 50, 63–80].

Te reality is that we have no other option than to transition to a sustainable housing future. Te question is how can it be achieved, over what time frame, and how do we ensure no household is left behind? Te current approach of housing provision will leave sustainable housing in the pre-development phase, to those who can aford to obtain it. Tose without the fnancial resources will be left behind. Tis will create an even wider divide of housing quality and performance based on a household's fnancial position. However, a more coordinated approach could ensure that those who are more vulnerable in our society are also able to engage with sustainable housing and the benefts that such housing provides. It is vulnerable and lower-income households who will beneft most from a sustainable housing transition in terms of the day-to-day impact of improved health and well-being outcomes and reduced living costs.

Te case studies in this book ofer hope that we can achieve a sustainable housing transition and a template for what we can provide. However, many of these cases have had challenges in getting to where they are now. For example, the Cape Paterson ecovillage in Australia will have taken almost 25 years from initial conception and purchase of the land, navigating the planning approval process, and construction of the site [81]. Tis is simply too long a time frame if we are to deliver on sustainability goals by 2050. What we need is a coordinated approach across a range of stakeholders.

Policy makers need to implement signifcantly stronger regulations to lift housing quality and performance. Tese regulations should be developed with a pathway to delivering sustainable housing by no later than 2030 for all new housing. Policy makers must also ensure that a pathway for retroftting existing housing is developed, with sufcient support for households and the wider housing construction industry to help facilitate a scaling up retrofts. Tis should be based on evidence about the existing housing stock's quality and performance, with the worst quality and performing housing addressed frst.1 Where evidence is not available, governments should prioritize collecting robust data sets on the condition of existing housing. Retroft policies should be planned to scale up to ensure that the industry can develop required skills and capacity, and retroft targets should be based on longer term sustainability goals. As a worst-case scenario, retrofts for all existing housing should be completed by 2050, but we would argue for a more ambitious timeframe of no later than 2040.

Housing construction industry stakeholders have a signifcant opportunity to drive the sustainable housing transition. Because of their size

<sup>1</sup>We note that not all existing housing will be suitable for quality and retroft improvements due to resources outweighing the beneft of a new build, or where there are strategic decisions to improve density e.g., by replacing a single dwelling with multiple.

and reach, key stakeholders such as large-scale housing developers and builders have the opportunity to lead by example and create signifcant change. Such stakeholders should be able to leverage their existing (or new) supply chains with economies of scale to ensure that any costs for the transition are kept low. Tere are signifcant market advantages for early adopters in that they will likely establish themselves as the authorities in the industry. However, this is easier said than done with signifcant resistance to change being an ongoing challenge. Education and support for housing construction industry stakeholders will be required to help create wider change, but it may not be enough on its own. Innovative fnancing or other options like fast tracking planning approval processes may also help drive an incentive for stakeholders to go beyond minimum standards.

Housing consumers need to become more educated about the decisions they make with their housing choices. While many people will not have many (or any) choices (e.g., renters in constrained housing markets), there are others who can use their decision making power to help infuence the wider housing sector. However, given the complexity of some elements of sustainable housing (e.g., technologies), consumers should not be expected to understand all the details of a house—much like we would not know all the complexities of a TV or car we were purchasing. It is critical that the provision of information about the performance of a dwelling is clear, robust, and verifable. Tere are examples already available that demonstrate this, such as the Energy Performance Certifcates across Europe which are providing consumers with better information. However, these certifcates will need to evolve to align with developments in the sustainable housing space (e.g., how to deal with two-way batteries in an electric vehicle). Perhaps the most important thing for consumers is to demand to be placed at the centre of housing decisions. It is these consumers who will live in the dwelling and feel the impacts of poor quality and performance. Tey should not be an afterthought.

Researchers also have a critical role moving forward. Robust evidence will be required to inform the sustainable housing transition and help guide policy making and industry changes. Tis needs to include both the successes and failures of sustainable housing. Research is required to drive innovation of design, materials, and technologies, but also to better understand how sustainable housing performs in the real world. Tere needs to be improved connection between technical and social research as there is limited beneft from scaling up technology if it is not being used appropriately by households. Social research can also provide necessary information about changing demographics and cultural practices, as well as support stronger equity considerations in housing provision and outcomes. While there is a signifcant amount of evidence already available, researchers need to be better at translating this evidence for policy makers, the housing sector, and consumers. We also encourage researchers to be more ambitious with their research, especially in discussing the implications of their research. As a research community, we must look beyond short-term research and at longer time horizons. Let us challenge the research community to be a key driver of sustainable housing (and wider sustainability). To do this, we need to move beyond the conservative nature of our research and challenge policy makers and the housing construction industry to do more.

In Chap. 8, we provided some thoughts on what an ambitious but realistic pathway would look like. In summary, we suggest all jurisdictions:


for three years between minimum performance changes). From 2035 onwards, requirements for existing housing at point of sale or lease could be aligned with new housing requirements.

While this book has largely been focussed on developed countries, a global sustainable housing transition must include developing countries. Te housing challenges in developing countries are often diferent from those in developed countries, and we must ensure that the sustainable housing transition in those locations can help address some of these different challenges. Much like with the global climate change approach, we will need developed countries to help support developing countries with the sustainable housing transition. Tis can be through sharing of knowledge, skills, materials, technologies, and research, but also likely through fnancial support to help such countries transform their housing industries.

#### **9.4 A Final Refection**

While it may seem like a monumental task to provide the types of housing we talk about in this book, the evidence and case studies throughout the book ofer us hope and guidance. Tere are policy makers, housing construction industry stakeholders, and housing consumers who have worked within their systems to drive change, as well as those who have pushed to create new ways of doing things. Tere are jurisdictions around the world banning the use of fossil fuels and incentivizing the electrifcation of dwellings. Tere are developers and architects straying from the path and delivering radically diferent and more sustainable housing options. Tere are consumers advocating for change and demonstrating alternative ways to live. But we only have a short window of time (perhaps no more than 15 years) to ensure that we change the way we provide housing. It is imperative that we scale up, embed, and mainstream these changes and alternatives, and leverage this progress to facilitate a global transition to sustainable housing. We also need policy makers, housing construction industry stakeholders, and housing consumers to collaborate to ensure the sustainable housing transition is undertaken in the most efcient and efective way. Tis might seem like a challenge, but as the evidence and case studies demonstrate, this type of housing future is possible.

### **References**


**Open Access** Tis chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence and indicate if changes were made.

Te images or other third party material in this chapter are included in the chapter's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

# **Index1**

**A**

Actors, v, 107, 124, 128, 130–133, 158, 159, 164, 165, 167, 168, 170, 171, 174, 177, 179, 181, 226, 228, 241 Afordability, 8, 10, 11, 13, 16, 33, 65, 66, 70, 73, 87, 88, 91, 97, 104, 105, 107, 147, 150–152, 158, 163, 167–169, 171, 178, 204, 207, 209, 210, 212, 213, 216, 219, 227, 240, 249, 259, 262 Apartments, 2, 75, 88–90, 97, 99, 156, 161, 206, 208, 209, 211, 213–215, 224 Appliances, 13, 50, 51, 65, 76, 179, 180, 200, 201, 218, 246, 263

Australia, 2n1, 5, 9, 11, 13–15, 34, 35, 38, 40, 42, 48, 50, 51, 64–66, 68, 70, 72, 73, 75, 87–90, 94, 95, 97–99, 101–103, 107, 108, 125, 131, 136, 137, 150, 162, 165, 169, 174, 180, 182, 183, 201, 204, 205, 208, 210, 211, 213–214, 219–220, 224–225, 228, 229, 245, 250, 268

**B**

Battery storage, 73, 95, 137, 166, 201, 207, 220, 228, 242 Baugruppen, 211, 229 BedZED, 15, 152, 218

<sup>1</sup>Note: Page numbers followed by 'n' refer to notes.

<sup>©</sup> Te Author(s) 2023

T. Moore, A. Doyon, *A Transition to Sustainable Housing*, https://doi.org/10.1007/978-981-99-2760-9

Benefts, 2, 3, 10, 12–15, 31, 32, 34, 48, 50–52, 61, 64, 71–73, 76–78, 85, 88, 89, 91, 101, 102, 106, 107, 123, 147, 150, 156, 160, 163, 167, 168, 170, 171, 178–180, 182, 184–186, 197, 199–201, 203, 204, 215, 225, 227, 251, 260, 262, 263, 268, 268n1, 270 Bottom of the market, 16, 39, 134, 172, 175, 264 Builders, 38, 44, 150, 151, 156, 164–166, 170, 207, 215, 223, 269 Building codes, v, 16, 17, 32, 34, 39–49, 51, 52, 75, 94, 102, 107, 108, 149, 151, 160, 174, 215, 264 Buildings, 1, 2, 6, 15, 16, 18, 31, 34–36, 38, 40, 41, 43–46, 49, 51, 62, 64, 67–69, 71, 74, 85, 87, 92–95, 97–100, 97n3, 102, 103, 137, 154–157, 159–163, 165, 168, 170, 172, 174, 176, 178, 181, 182, 184, 186, 201–207, 209–212, 214–218, 216n5, 220, 223, 224, 229, 242, 243, 246, 250, 252, 261, 263, 264, 266

#### **C**

Canada, 5, 14, 44, 48, 66, 74, 89, 94, 98, 99, 108, 150, 156, 163, 201, 203–205, 207–211, 218–219 Cape Paterson ecovillage, 15, 224–225, 268


Climate zones, 13, 86, 99, 103, 158, 202, 213, 262 Co-housing, 182, 212–213, 229, 249 Compliance, 40, 45, 46, 107, 108, 176, 184 Construction, vi, 1, 2, 11, 12, 15, 16, 34, 35, 40, 45, 49, 62–64, 70, 75, 76, 79, 86, 87, 92–95, 97, 100, 102, 107, 108, 129, 137, 150, 152–154, 156–158, 160, 161, 163, 165–169, 171, 174–176, 181, 183, 186, 198, 199, 204, 206, 208, 213, 218–221, 223–227, 229, 245, 249–252, 261, 262, 268 Construction industry, 12, 15–17, 32–34, 36, 38, 40, 43, 45, 62, 63, 68, 70, 72, 76, 101–103, 106–108, 128, 153, 154, 156, 157, 160, 165, 169–171, 184, 252, 268–271 Consumers, 15–17, 32–34, 36–39, 49–51, 65, 68, 90, 92, 102, 106, 126, 131, 132, 137, 149, 150, 152, 154, 155, 157, 158, 169–172, 176, 177, 181, 184, 185, 216n6, 226, 230, 245, 247, 249, 251, 252, 263,

264, 269–271

	- 201, 204, 205, 207, 214, 228, 241, 267

99, 165, 212

Developers, 150, 160, 164–166, 171, 225, 229, 269, 271 Dockside Green, 218–219 Double-glazed windows, 33, 64, 73, 74, 201 Draught sealing, 13

#### **E**

Ecological modernization, 124, 124n1 Economic benefts, 13 Education, 7, 49, 50, 158, 224, 247, 264, 269 Electric vehicles, 63, 131, 178, 183, 201, 228, 242, 248 Electrifcation/all-electric, 178–180, 200, 263, 271 Embodied energy, 89, 89n1, 92, 93, 155 End of life, 1, 75, 92–94, 151, 155, 181, 198, 220–224, 252, 261 Energy, vi, 1, 2, 36, 40, 65, 85, 88, 126, 151, 198, 242, 261 Energy efciency, vi, 35–39, 43–46, 50, 65, 71, 90, 91, 93, 95, 131, 204, 213, 265 Energy networks, 2, 12, 14, 63, 66, 73, 77, 95, 96, 242, 248, 262, 266 Energy Performance Certifcate, 15, 35–37, 74, 263, 269, 270 Energy Star, 50, 51 Equity, 6, 15, 18, 46, 62, 72, 91, 94, 173, 183, 186, 221, 228, 270 Erneley Close, 202–203 Ethics, 128, 129, 185, 186, 199

European Union (EU)/Europe, 2n1, 11, 16, 36, 37, 43, 73, 93, 96, 98, 101, 103, 176, 205, 210, 222, 242, 246, 263, 264, 269 Everyday life and practices, 177–180,


#### **F**

Facilitating the transition, 242–248 Feed-in-tarif, 51, 52, 73, 228 Flammable cladding, 93, 108, 150, 174, 184 Floor area, 65, 89–92, 161, 208, 265 Fossil fuel, vi, 5, 67, 71, 73n1, 95, 130, 131, 176–177, 179, 180, 248, 271 Fuel/energy poverty, 11, 71, 101, 175, 185, 266

#### **G**

Geography, 129, 132, 160–164, 200, 201, 205, 206, 208, 211, 216, 218, 219, 221, 222, 241, 267 Governance, 48, 101–104, 106, 124, 125, 128, 173–177, 183, 185,

206–208, 210, 215, 218, 221, 222, 226, 228, 230, 241, 242, 266, 267 Government, 2n1, 3–5, 16, 31, 32, 34, 39, 40, 43, 46–48, 50, 52, 63, 68, 72–74, 79, 91, 101–103, 107, 109, 126, 134, 136, 150, 159, 169, 173, 175, 180, 204, 206, 207, 215, 218, 228, 230, 248, 250, 263, 268 Greenhouse gas emissions, 1, 2, 5, 31, 42–44, 48, 49, 51, 66, 67, 69, 71, 72, 89, 93, 95, 220, 261 Green mortgages, 229–230 Green new deal, 70–72 Guiding principles, 149–153, 157, 184, 200–202, 205–211, 213, 214, 218, 219, 221–225, 241, 267

#### **H**

Half a house, 186

Health and well-being, 2, 8, 11, 12, 34, 45, 46, 63, 71, 78, 98, 100, 101, 104, 105, 107, 123, 147, 151, 158, 172, 175, 178, 179, 186, 200, 202, 227, 240, 251, 261–262, 268 Heating and cooling, 11, 13, 14, 40, 76–78, 95, 108, 108n4, 153, 155, 158, 178, 198, 203, 205, 216, 216n6, 226, 262, 265 Heat island, 14, 90, 98, 99, 161 High performance, 45, 199, 200,


**I**

Inclusionary zoning, 252 Indoor air temperature, 40, 101, 203 Industrial structures and organizations, 164–169, 201, 204, 213, 221, 223, 225, 227, 228, 241, 267 Information, 16, 33, 36–39, 49, 50, 77, 134, 157–159, 170, 182, 211, 226, 246, 249, 250, 263, 269, 270 Innovation, 2, 13, 19, 32, 40, 42, 62, 63, 72–79, 92, 107, 108, 124–126, 128, 130, 132, 153, 155, 159, 167, 168, 171, 174, 175, 177, 182, 199, 217, 223, 224, 228, 240, 241, 245, 248, 252, 253, 260, 262, 263, 270 Insulation, 10, 33, 67, 99, 154, 155, 200, 201, 215, 246, 263 Intermediaries, 38, 39, 44, 132


#### **K**

Knowledge, 2, 4, 50, 70, 86, 109, 130, 132, 151, 154–160, 165, 166, 198–201, 208, 209, 213, 218, 220–222, 225, 226, 229, 241, 248, 260, 267, 271

**L**

Landscape, 125, 128, 133, 163, 169, 215, 219 Laneway houses, 207–208 Layout, 86–88, 160, 208, 266 Leaky homes/condos, 94, 108, 150, 184 Lease, 14, 16, 74, 243, 246, 270, 271 LEED, 94, 217, 218 Life cycle, 2, 63, 75, 88, 92, 150, 151, 154, 155, 160, 204, 261 Living Building Challenge, 45, 46, 94, 172, 264 Living costs, 2, 13, 34, 63, 101, 102, 104, 123, 202, 227, 229, 262, 268 Lochiel Park, 15 Lock in, 66, 98, 130, 160 Low carbon, 1–7, 12, 15–18, 31, 35, 42, 44, 45, 49, 61–64, 67–69, 79, 85, 101, 110, 123, 124, 131, 133, 147, 159, 173, 181, 197, 240, 242, 243, 247, 261, 263, 264 Low hanging fruit, 12, 67 Low income, 11, 12, 44, 65, 185

#### **M**

Mandatory disclosure, 16, 34, 36, 39, 49, 246, 270 Market failure, 15–17, 31–39, 41, 49, 52, 123, 133, 147, 226, 263, 264 Markets, v, 6, 14–16, 32, 33, 36, 38, 39, 73, 75, 76, 79, 86, 90, 104–106, 108, 125, 126, 130,

134, 137, 155, 157, 159, 164, 165, 167, 169–173, 175, 180, 181, 186, 202, 204, 206, 207, 217, 219, 221, 226, 228–230, 241, 243, 245, 249, 263, 267, 269 Materials, vi, 1, 2, 5, 8, 15, 31, 32, 40, 45, 49, 62–64, 67, 70, 74–77, 79, 86, 87, 89n1, 92–95, 100, 107, 108, 130, 137, 150–159, 162, 163, 165, 166, 168, 172–175, 177–179, 181, 184, 186, 198–200, 205, 206, 209, 218, 220, 221, 223–226, 230, 245, 247, 248, 252, 259, 261–263, 266, 270, 271 Minimum standards, 15, 157, 243, 264, 269 Modern slavery, 94, 184 Multi-level perspective (MLP), 125, 126, 244

#### **N**

Nationwide House Energy Rating Scheme, 34, 40, 41 Natural disasters, 4 Neighbourhood, vi, 17, 18, 47, 77, 86, 91, 96–100, 131, 160, 162, 163, 198, 200, 202, 205, 206, 208, 211, 216–220, 222, 224, 241, 266 Neo-classical market, 15, 31, 33, 149, 263 Never Too Small (NTS), 208 New housing, 1, 15, 35, 43–45, 51, 52, 61, 64, 66, 67, 69, 72, 75,

97, 99, 100, 103, 129, 134, 149, 150, 154, 173, 180, 200, 213, 220, 222, 224, 226, 239, 242, 243, 246, 250, 261, 263–265, 268, 271 New Zealand, 10, 78, 94, 104, 108, 150, 210 Niche, 18, 73, 107, 125–128, 130, 132–138, 159, 171, 227, 240–242, 244 Nightingale Housing, 15, 213–214, 249

**O**

	- 219, 263

Performance gap, 102 Physical attributes, 153–156, 198, 200–202, 204–208, 211, 213, 215, 216, 218–221, 223–227, 241, 252, 267 Place, 2, 8, 13, 46, 97, 101, 105, 107, 124, 127, 129, 130, 150, 160–165, 173, 175, 176, 180, 182, 210, 211, 214–216, 242, 246–248, 259, 262, 266 Planners, 11, 17, 100, 164, 215 Planning, v, 17, 31, 32, 40, 46–49, 52, 64, 86–92, 94, 107, 149, 157, 160, 162, 163, 174, 215, 217, 250, 252, 264, 266, 268, 269 Planning schemes, 17 Policy, 2n1, 7, 10, 16, 17, 19, 31, 32, 35, 39, 43, 44, 61–63, 68, 70, 73–75, 91, 94, 101–104, 106, 107, 123, 124n1, 125, 126, 128, 130, 132–134, 137, 163, 169, 170, 173–179, 182, 206–208, 210, 215, 220–222, 226, 228, 230, 240, 241, 261, 267–270 Policy makers, v, 3, 5, 10–12, 17, 31, 34, 36, 46, 62, 67, 68, 74, 77, 91, 101, 109, 137, 171, 179, 226, 251, 268, 270, 271 Poor quality housing, 10, 100 Population, 5–7, 9, 11, 62, 68, 78, 88, 96–98, 100, 106, 136, 161, 164, 206, 209–211,

	- 175, 183–186, 266

Power, 127, 128, 130, 131, 158, 169–173, 204, 206, 216n6, 217, 219, 221, 226, 228, 229, 241, 267, 269 Practices, 5n4, 6, 15, 18, 19, 32, 38, 50–52, 62, 70, 77, 78, 86, 88, 93, 94, 107, 108n4, 109, 124, 125, 130, 132, 132n2, 134–136, 149, 152, 154, 156, 157, 164, 165, 167, 168, 170, 171, 175, 177–180, 182–186, 197–231, 240, 241, 247, 249, 253, 261, 264, 267, 270 Prefabrication, 153, 156, 160, 168–169, 204 Profts, 33, 34, 149–151, 153, 160, 165, 167, 184, 229 Prospects, vi, 19, 240, 259–272 Protection, 4, 8, 126, 133, 175, 176, 217, 252 Public/social housing, 12, 13, 72, 149, 169, 202, 223, 224 **Q** Quality, vi, 6, 9–18, 31–37, 39, 40, 42, 46, 48, 49, 51, 52, 61, 64, 65, 68–71, 73–79, 85–87, 90, 95, 97, 98, 100, 102, 104, 105, 123, 133,

136, 137, 147, 149–155, 157, 158, 160, 168–170, 173, 174, 176, 181, 183–186, 201, 205, 217, 223, 230, 240, 243, 245–247, 249, 251–253, 262–264, 267–270, 268n1

**R**

Rating tools, 45, 94, 134, 172–174, 178, 217 Real estate agents, 38, 229 Rebates, 34, 51, 73, 73n1, 103, 133, 228, 230, 247, 264 Reclaimed land, 161 Regenerative, 6, 46, 172, 221 Regime, 5, 5n4, 18, 46, 79, 106, 123, 125, 127, 128, 131–137, 132n2, 147, 149, 150, 153, 156, 157, 159, 160, 164, 166–171, 173–175, 177, 179–181, 183, 184, 187, 226, 228, 240–242, 244, 247, 263, 266, 267 Regulations, 16, 32, 33, 40, 41, 45, 47, 51, 68, 74, 75, 85, 99, 101, 103, 107, 108, 123, 130, 132, 133, 147, 157, 161–164, 168, 171, 173–177, 180, 181, 184, 206–208, 210, 215, 218, 221, 222, 226, 228, 230, 241, 244, 245, 263, 264, 267, 268 Renew, 182–183 Renewable energy, 13, 44, 71, 77, 89, 95, 96, 130, 131, 155, 172, 179, 201, 206, 216, 220, 225, 227, 242, 246–248, 263, 266 Rental, 37, 74, 75, 78, 103, 104, 159, 204, 208, 212, 219 Resources, 3, 6, 7, 11, 44, 73, 92, 93, 104, 134, 149, 152, 165, 179, 184–186, 200, 205, 206,

209, 212, 214, 216, 221, 260, 267, 268n1 Retroft, vi, 6, 13, 16, 37, 43, 52, 64, 65, 69–72, 74, 78, 103, 134, 147, 149, 152, 158, 171, 173, 185, 200, 202, 226, 227, 230, 243, 246–248, 250, 251, 265, 268, 268n1 Risk, 41, 66, 87, 94, 97, 153, 165, 168, 205, 230, 250

**S**

Sale, 14, 16, 37, 38, 219, 243, 246, 270, 271 Scaling up, 43, 242, 245, 248, 251, 266–268, 270 S-curve, 125–127 Semi-detached, 2 Shared housing, vi, 18, 65, 104, 197, 209–212, 241 600sqftandababy, 209 Slums, 9, 11, 67, 96, 210, 262 Smart homes, 13, 76, 77, 178, 263 Smith, Adrian, 134, 137, 148, 154, 240, 241 Social movements, 132, 177, 180–183, 201, 205, 228, 241, 267 Socio-technical dimensions, 18, 124, 138, 147–187, 197–199, 198n1, 230, 239, 241, 242, 267 Solar photovoltaics (PV), 51, 72, 73, 77, 96, 131, 136, 207, 263

Statutory planning, 47, 264 Strategic land use planning, 46 Subsidies, 73n1, 92, 103, 228, 230, 264 Supply chain, 92, 94, 129, 151, 153, 154, 166, 175, 184, 221, 245, 248, 253, 269 Sustainability transition, 8, 123–138, 147, 164, 171, 173, 182, 183, 197, 239–241, 244, 253, 266, 267 Sustainable development, 6, 62, 163, 167, 218 Sustainable Development Goals (SDGs), 7, 67, 69, 91, 96, 176, 261 Sustainable housing, v, 1–3, 11–19, 31–39, 42–45, 49, 50, 52, 61–64, 66–79, 85–110, 123–138, 147–187, 197–231, 239–253, 259–272 benefts, 3, 15, 31, 34, 61, 78, 85, 101, 123, 182, 185, 197, 260, 263, 268 defnition, 6, 16, 63, 148, 199, 264 transitions, 3, 18, 19, 62, 79, 85, 86, 110, 129, 133–138, 147–187, 198, 239–253, 259–272

#### **T**

Targets, 43, 45, 62, 66–69, 85, 89, 91, 93, 101, 103, 172, 176, 202, 239, 242, 246, 247, 268 Tax incentive, 51, 264

Technology, vi, 2, 4, 5n4, 13–15, 40, 44, 45, 49, 51, 62–65, 70, 73, 73n1, 77, 79, 86, 87, 92–96, 100, 107, 108, 124–126, 130–132, 132n2, 137, 150, 153–157, 163, 164, 166, 167, 174, 175, 177–179, 181, 183, 184, 199, 203, 205, 219, 226, 228–230, 240, 241, 243, 246–248, 252, 262–264, 266, 269–271 Tree Generation House, 214–215 Tiny house, vi, 76, 170, 205, 207 Trees, 6, 14, 161, 219 2030, 7, 9, 44, 61, 62, 68, 69, 72, 85, 176, 245, 268, 270 2050, 4, 63, 64, 66, 69, 85, 89, 96, 102, 123, 176, 200, 220, 242, 245, 247, 249, 260, 265, 268

**U**

United Kingdom (UK), 10, 11, 13, 15, 35, 36, 43, 44, 51, 64, 69, 71, 73, 74, 78, 88, 90, 94, 101, 104, 108, 125, 131, 133, 134, 136, 152, 202–203, 205, 210, 218, 222 United Nations (UN), 8–10, 67–69, 96, 100, 259 United States of America (USA), 5, 9, 12, 14, 15, 48, 50, 52, 65, 66, 77, 89–91, 97, 99, 102, 103, 125, 137, 156, 162–164, 201, 204, 210, 211 Universal Declaration of Human Rights, 8

Urban, 2, 10, 13, 14, 17, 46, 47, 85–87, 90, 91, 96–100, 107, 129, 130, 133, 157, 161, 162, 175, 182, 183, 206, 209, 211, 212, 215–217, 219, 225, 229, 240, 262, 266 design, 47, 219 infll, 97, 97n2 living labs, 130, 133, 175 renewal, 97, 97n3 Urbanization, 96 Users, 42, 132, 136, 169–173, 177–179, 185, 202, 204, 206, 217, 219, 221, 226, 228, 229, 241, 267

**V**

Value, 14–16, 34, 37, 46, 48, 87, 94, 105, 124, 149–151, 168, 181–183, 202, 203, 213, 221–223, 226, 228, 251, 262, 263 Vancouver House/Vienna House, 159–160 Vulnerable, 4, 5, 7, 10, 12, 78, 100, 128, 184, 185, 251, 268

**W**

Waste, 1, 76, 93, 102, 152, 168, 212, 216n6, 220, 221, 224, 225, 261

Water, 2, 6, 11, 13, 41, 45, 49, 50, 92, 96, 130, 150–152, 172, 173, 176, 200, 201, 207, 212, 219, 220, 224, 246, 263, 264

WELL Building Standard, 172 Whistler Housing Authority Employee Housing, 203–204 White Gum Valley, 219–220 World Overshoot Day, 5, 5n5

**Z**

Zero carbon, 2, 43, 51, 63, 93, 101, 108, 173, 200, 219, 261, 265 zHome, 15 Zoning, 47, 163–164, 207, 208, 252