Keywords

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 financial 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 benefits 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 identified ten core socio-technical dimensions from previous research and our own reflections, 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, neighbourhood-scale housing, circular housing, and innovative financing for housing. Through these themes, we address sustainable housing at different 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 different 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 different 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 fit 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).

Table 7.1 Summary of the socio-technical dimensions the themes engage with
Full size table

7.2 High Performing Housing

The type of sustainable housing we have described in this book provides significantly 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,Footnote 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 (knowledge) from different 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 significantly improve health and well-being outcomes that impact everyday life and practices as well as ethics of housing [1,2,3,4]. Others will no doubt have different definitions of what a sustainable house is, and it almost does not matter how a sustainable house is technically defined if it is centred around the core ideas discussed in this book. We also know that the way we define 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.

There are important benefits of moving from incremental performance improvements to significant 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. This means changing both the guiding principles and physical attributes of housing. Therefore, all new housing that is not built to that future standard will need to undergo retrofits 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-off retrofit activities, deep retrofit is required to provide significant emissions reductions, and also to provide a greater range of benefits for the household such as reducing operating costs and improve health and well-being outcomes [4,5,6,7,8]. There are also a number of wider benefits beyond housing that could be achieved through significant 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 retrofitting an existing dwelling, and the scale (e.g., individual dwelling or neighbourhood/city) [3, 9]. Experts in different jurisdictions will be able to guide the specifics 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:

  • The size is only as large as required for the needs of the occupants

  • Optimal orientation

  • Use of passive design principles

  • Improved thermal performance through increased insulation and window glazing

  • Use of local and robust materials

  • Maximizing energy and water efficiency (e.g., appliances)

  • All-electric energy provision

  • Inclusion of rainwater tanks plumbed into key internal uses where safe to do so

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

For existing homes, physical attributes and knowledge include:

  • Sealing up gaps and cracks

  • Improving or adding ceiling, wall, and underfloor insulation

  • Ensuring good quality blinds/curtains, and adding seasonal external shading options where possible

  • Replacing inefficient appliances with modern smart energy and water efficient appliances like heat pumps (heating, cooling, and water heating)

  • Adding secondary glazing or window films, or undertaking full double-glazed window replacement

As discussed earlier in the book, there are a number of formal and informal ways to provide significantly 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 different 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 benefits 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 certified to the standard, with more than 100,000 additional non-certified dwellings estimated to have been constructed following these principles. The increasing numbers of Passive Houses highlights how they are setting new guiding principles and requirements for physical attributes, and starting a social movement [10]. The 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. The aim (guiding principles and knowledge) of Passive House is to achieve an energy efficient, thermally comfortable, and affordable house. To be certified 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.

Table 7.2 Performance targets for a European climate for Passive House performance for new dwellings and retrofit [adapted from 10]
Full size table

7.2.1 Erneley Close—United Kingdom

Erneley Close is a social housing development in Manchester (UK) that underwent a retrofit to EnerPHit Standard in 2015. The project involved the owner (One Manchester) (markets, users, and power) undertaking a retrofit of 32 two-bedroom walk-up flats for a cost of £3.1 m. The 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 significant improvement in overall performance. Research that monitored the performance of the refurbished dwellings found that they performed significantly 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]. This contributed to a reduction in energy costs for households, with tenants reporting savings of up to £100 a month. As one tenant reflected:

Before all these works my flat was freezing. I was spending about £15 per week on heating the flat 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 off, 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. There’s a real community spirit here now … My little grandson calls the building ‘Nanny’s castle’ because he says it’s magical. [14]

The 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. There was a significant uplift in community value and pride in the area—benefits 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 significantly better due to the quietness in the dwelling from the improved building envelop. This 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

The 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 affordable for local income earners and retirees in perpetuity. As a resort municipality, Whistler struggles more than most with housing affordability. In 2022, the municipality completed the Whistler Housing Needs Report (mandated by the provincial government) and one of the more significant findings was that close to 90% of Whistler’s workforce could not afford 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]. The 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. The building meets Passive House standards and it was designed and constructed using a prefabrication system. The physical attributes of the building included the use of offsite modular construction, a panelling system, and simple massing. These helped to reduce costs and increase productivity, as well as increase energy efficiency. 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. This benefit 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

The 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 significant 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 low-density 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 find a growing tiny house movement although, the movement has taken hold in some European countries including France, Germany, and the Netherlands [25]. This 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 Thoreau, 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]. This 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 identified 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 financial 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. Densification or urban consolidation involves increasing or maintaining the density of housing in established residential areas. There are numerous ways to achieve this goal with more common ones including height and infill. 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. Infill housing generally “fits within” an existing neighbourhood without significantly altering its character or appearance. Examples of infill 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]. The 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 find a “parking spot”. This means that these houses can be located on lots with single family (R1) zoning or on rural properties. The mobility of tiny houses also makes it necessary (or an opportunity) to have the houses operate off-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 off-grid elements increase the sustainability of these houses, as does the size of the house itself. The 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 affordability 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]. There is a strong do-it-yourself culture associated within the everyday life and practices of residents which relates both to environmental and affordability concerns. However, as the popularity of the typology has grown, there are now dedicated tiny house builders for designing and constructing tiny houses. This shift is similar to what we find 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.Footnote 2 These 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 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. The locations and size of laneway houses is dependent on the local policy, regulation, and governance such as zoning and bylaws. The 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 floor 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.Footnote 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. Through their YouTube Channel, Instagram and Facebook accounts, hardcover book, and website, they feature designers and their award-winning 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.

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.Footnote 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. There is a strong focus on living with less not only in terms of square footage, but also when it comes to the “stuff” we put in our homes. While not always explicit in the material, affordability 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 offering small space design consults. The 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 offers a sense of community and confidence 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. This 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 buildings, families lived in individual units and spaces were not shared. These buildings were overcrowded and referred to as slums. Those who could afford better living conditions and larger spaces moved to areas outside of the cities, what we now call the suburbs. Early suburban developments solidified 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. These 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.

The 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. The 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). The 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) differed from environmental to spiritual to anti-government, among other ideologies. But, each communal approach represented a radical departure from the nuclear family model. The 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 affordability.

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 affordability was identified 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 one-bedroom dwellings, but we are missing middle and alternative housing options, such as shared housing.

Buildings, including housing, and neighbourhoods can offer 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. This can be done in intentionally communal spaces such as lobbies and circulation, as well as shared laundry facilities, gardens, rooftop terraces, and other amenities. These 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.

There are many arguments and claims of greater sustainability and reduced environmental impact for shred housing, when compared to mainstream housing [31]. This 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 efficiency [33]. Shared housing offers opportunities for more efficient use of land through use of space and density. The scale and communal nature of shared housing can support effective use of resources and waste management practices. These include more elaborate composting and recycling programmes; grey water filtration systems; rainwater collection; community scale energy projects; and sharing resources and bulk purchasing [32].

7.4.1 Co-Housing—Globally

The 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). There 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, different types of tenures (owner-occupier, rental, co-operative), different numbers of occupants or residents, different demographics, and different 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 first 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 affordability 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 (affordability)” [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). The 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]. This 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 affordability outcomes. The guiding principles of Nightingale Housing have since evolved and now include sustainability, reductionism, energy efficiency, affordability, 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). Through knowledge sharing, there are now 15 completed developments with seven more under construction and another ten upcoming [42]. While the developments go significantly 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.

The 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 difference is the removal of individual laundries in favour of a shared laundry located on the roof of developments. The 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]. The 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). The ground floor of these developments also typically includes a combination of office 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. The Three Generation House, is a single multi-storey building located in Amsterdam Noord and designed by BETA Office 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). The 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. The aim of the project was to create a house that offered all the benefits of shared spaces and living together without sacrificing privacy. The 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. The 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. The central circulation allows for future adaptability of floorplates so that studio apartments can be carved out of existing spaces or floor 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 floors 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 influences the result. As discussed in Chap. 2, buildings must be built to the minimum specifications outlined in building codes, where planning is responsible for approving developments which includes location, type, size, and mix, among other considerations.

There is no prescribed definition of the neighbourhood-scale. The size or attributes are context specific. 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.Footnote 5 The 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-off buildings, offers opportunities to combine resources and coordinate efforts, and to interact with other institutional structures and organizations [46]. Examples include district heating and cooling,Footnote 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 affordability.

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 configuration, transport networks, infrastructure networks, and environmental conditions. Site types refers to the status of the land and its surroundings. There are generally three common approaches: greenfield (development land or change of land use), brownfield (previously developed land), and infill (un(der)development land boarded by developed land). Greenfield sites are most often found in dispersed (sub)urban forms while brownfield and infill can be found in a variety of compact urban forms. These 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 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. The 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.

The compact urban forms mentioned above represent different approaches that can be adapted to different locations and contexts. There are also rating tools that have been developed to “certify” developments that focus on specific 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]. This collaboration brought together key stakeholders from the market, users, and power dimension. The impetus for the new LEED classification 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. The aim of LEED ND was to encourage community planning processes to support “green” innovation and transformation [49]. The LEED ND rating system comprizes two adaptations: LEED ND: Plan and LEED ND: Built Project, which have certification options unique to this rating system. Like all LEED programmes, neighbourhoods can achieve one of four levels of certification: certified, silver, gold, or platinum. There are five 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. The credits are then calculated to determine the level of certification. For example, for smart location and linkage, agricultural land conservation and floodplain 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.Footnote 7 DSG is a brownfield redevelopment (geography) that incorporates Smart Growth principles, LEED ND Platinum certification, building reuse, economic development, and environmental regeneration. Prior to redevelopment, the land was used for shipping and shipbuilding, timber processes, an oil refinery, and an asphalt plant. All of this left a heavily contaminated shoreline with vacant buildings. The 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 financing 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. The physical attributes of the development itself are comprized of LEED Platinum buildings, a wastewater treatment plant, a biomass plant, electricity metres, efficient appliances, reclaimed materials, car co-op memberships, and other amenities. The 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 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 affordability 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 financial 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. The development is located 20 km from Perth and 3kms from the City of Fremantle. The 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]. The physical attributes of the project have been designed to allow all homes to integrate passive solar design principles and other sustainability initiatives. The range of lot sizes and configurations provides opportunities for housing diversity and a range of price points, specifically to support trends towards smaller households for singles, couples, and seniors. The 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 infiltration basin and onsite storm water retention systems [51]), improving biodiversity outcomes, transport, cultural development, housing affordability and access, and food sourcing [52]. There is a focus on ethical aspects through a range of dwelling types, affordable housing typologies and rental/ownership options, and on reducing residents’ costs for energy and water [53]. The neighbourhood scale of the project is also considered in the community scale battery storage system and the peer-to-peer renewable energy-trading scheme. The WGV project is structured within multiple policy frameworks including the City of Fremantle’s Local Planning Policy 3.15 [54] and the project specific 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 retrofitting of existing housing [57]. The impact from materials is not only in the construction phase, but also through the generation of waste during construction, through-life (maintenance), and at end of life. While specific 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]. The 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 significantly reduce its environmental impacts across all phases of a dwellings life by addressing physical attributes, knowledge, and everyday life and practices. This includes not only reducing energy and water consumption by occupants, but also through reducing impacts from materials, ensuring we use significantly less raw materials in our construction and maintenance of housing, and designing for deconstruction and reuse at end of life. The 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]. The 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].

There is no universally agreed upon definition 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. This 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 definition 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 define 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 efficient and regenerative operation (physical attributes), and enhances value across the design, construction use, and end of life phases of a dwelling. Circular housing promotes affordable, accessible, fit-for-purpose housing (markets, users and power) that is appropriately located (geography) so that it addresses social, economic, and intergenerational equity concerns (ethical aspects). This can be provided across various scales from the individual dwelling to across a community or city-level (knowledge). This 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 retrofitted 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, significantly improving physical attribute outcomes [68]. Circular housing is emerging in different 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 retrofitting 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.

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

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. Their analysis showed a variance across housing types and identified significant 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 finishes could largely be removed by hand to reduce damage to the structure and other large building components such as windows, roofing, and framing could be removed with typical machinery (e.g., excavators or cranes).

7.6.1 Circle House—Denmark

There 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]. The residential typologies are a mix of two- and three-storey terraced houses and five-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. The 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]. The Circular House project also engaged with other guiding principles of the circular economy, including significantly reduced environmental impact and improved quality and durability [71]. The 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. The 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]. The site of the project contained four ten-storey apartment buildings that had been built during the 1960’s and were no longer fit for purpose [72]. After demolishing one of the buildings and sending the waste to landfill, 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. This 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]. There was also a focus on providing on-site solar generation, a closed water cycle, and reducing car use.

The 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 affordable 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. The 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

The Cape Paterson Ecovillage is located on the outskirts of Cape Paterson, a rural town 120 km south-east of Melbourne (Australia). The 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].

The 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 significantly 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 benefits including reducing food miles, healthier eating, opportunity for selling produce, and providing a system to compost waste products created on site [75]. Further benefits 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 financial cost for providing improved sustainability continues to be a challenge that contributes to the slow uptake of sustainable housing and sustainable communities more broadly. This relates mostly to capital costs, but also in some cases to the ongoing costs (e.g., maintenance) of sustainability inclusions. The challenge of perceived higher financial costs persists despite an increasing amount of evidence (knowledge) from research and real case studies demonstrating that the performance of existing housing can be significantly 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. This conflicting information creates confusion, not only for consumers, but also for policy makers, the industry, and even researchers!

The question of financial 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 afford 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 retrofit of existing housing, but also through the financing 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. This 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. The 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 retrofit), costs will likely be higher due to limited stakeholders in that space who are able to do the work, and also because cost efficiencies from economies of scale will not yet be realized across current industrial structures and organizations. The 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 finance.

As there are increasing housing affordability 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 affordable for everyone. There 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 through-life 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, financial, and environmental benefits have been, time and again, shown to outweigh any initial costs [2, 7, 77,78,79,80]. Additionally, most people who buy a dwelling do so through borrowing money from a financial institution. This means that any additional cost is not strictly something that needs to be paid for upfront. Research has shown that improved performance can often offset any impact on additional mortgage repayments and can lead to mortgages being paid off years earlier, saving the household tens of thousands of dollars in interest [77,78,79].

In an attempt to create a more level playing field 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 financial mechanisms. Perhaps the most widely implemented example across the world has been the use of financial rebates or subsidies through policy, regulations, and governance to help reduce the capital cost of installing solar PV (and other renewable technologies). This is typically provided by governments who see this as a way to make certain sustainability technologies more affordable and to help drive uptake. The 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 offer 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. The rapid uptake of residential solar PV in Australia from the mid 2000’s is an example of where this type of financial innovation, along with generous feed-in-tariffs, has helped drive significant change within the markets, users, and power dimension [81]. Battery storage and electric vehicles are also seeing similar financial assistance in many regions. However, this type of financial innovation is not without critique, with concerns about access and equity being raised about such approaches [82,83,84,85].

In recent years, a range of financial 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 finance and trying to shape markets. No longer is this just the domain of governments, but increasingly financial institutions, organizations and others are becoming involved. There has also been a shift in how finance 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 financial 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 affordable urban co-housing model that emerged in Germany in the 1990s. This 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 efficiencies 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 profits [86]. Baugruppen can be any type of housing, but has largely been provided in multi-storey, multi-family buildings [87]. This 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]. There are differences to how these are structured across different jurisdictions or companies, but there are common elements to the base intent. For a green mortgage, the lender will offer 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). This reduced rate might be for a period of time or the entirety of the home loan. There are also variances on this where the lender may allow for greater borrowing capacity knowing the living costs will be lower [90]. The intent is that it will encourage households to include more sustainability elements with the knowledge that any additional costs will be offset by lower mortgage repayment rates. For the lender, they are reducing the risk of missed loan payments or defaulting on loans as the evidence finds 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. This 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 financial rebate directly to the household or supplier once the sustainability activity has been implemented. Typically, these types of approaches will offer a certain percentage of the cost calculated based on what the government feels is a balance between providing financial 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 retrofit 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

This 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. These cases have also largely been one-off examples. We need to find ways to scale up these examples and accelerate the transition to a sustainable housing future. In the following chapters, we reflect on what we have covered in the book so far and discuss what this means moving forward.