Housing adequacy in an informal built environment: case studies from Ahmedabad

Informal settlement is a spatial manifestation of inequality, in that people turn to informal solutions for housing when formal ones are out of reach, usually because of financial constraints but also other factors such as social exclusion. However very little is known about the architectural and urban forms that constitute informal settlements, and thus how this inequality manifests spatially, and what specifically is inadequate in these settlements is not currently well understood. We use the framework of the United Nations Right to Adequate Housing as a benchmark to determine whether housing is contributing to inequality through one or more failures of adequacy, in which case we define these as being inequitable housing. We analyse the architecture of four cases within three informal settlements in Ahmedabad, Gujarat state, India, to examine how these urban forms both reflect and/or remedy multi-scalar urban housing inequalities. Four key physical spaces are found to be important: the dwelling’s site, resident’s control over dwelling design and construction, the design of the dwelling threshold, and the characteristics of shared open spaces. In the right combination, the quality of these physical spaces in informal settlements can contribute to informal settlement residents achieving housing adequacy. A better understanding of the built environment of informal settlements can enable designers and planners to harness the potential of informal settlement environments that are assets of the urban poor, create a context that stops informal settlements becoming ‘slum-like’ and help construct pathways towards urban equality.


Introduction
Informal settlements are a manifestation of inequality. As new urban residents invariably choose formal housing when they have access to resources and appropriate choices, informal settlements occur where formal housing is unable to be attained. Poverty is one of the most consequential factors in attaining the UN Sustainable Development Goal in housing 1 3 (Adabre et al., 2021). Informal settlements are, by their nature, an attempt by residents to produce affordable and accessible land, housing, and infrastructure in urban areas (Sivam & Karuppannan, 2002). However, these informal responses face a range of problems such as lack of recognition or service provision by government, poor locations that are vulnerable to climate impacts, demolition, and so on. Thus, it is well known that informal settlements are an inequitable housing option, but little is known about the specific forms that urban planning and design take in informal settlements and thus in what particular ways the housing is inadequate. They are more commonly analysed in terms of their economies, the health effects of living in informal conditions, and the purported solutions, including 'slum clearance' (Bhan, 2009).
In this paper we take four residential cases within informal settlements in Ahmedabad in the state of Gujarat, India, to examine the ways in which the urban form both reflects and/or remedies the housing inequalities faced by residents and describe the specific ways in which the inadequacy of housing is manifested. We use the United Nations Right to Adequate Housing, and the criteria through which they define housing adequacy, as the benchmark against which to assess each case and to examine what is lacking in informal settlements and contributing to housing inequality. We ask how the specific built environments of these informal settlements afford the needs and aspirations of their residents, and where they do not, to establish a case for better knowledge on which to base policy, governance, and regulation to improve the problems that beset residents of informal settlements.
Rising levels of socio-spatial inequality in India are manifesting more strongly in megacities experiencing rapid urbanisation (Perez & Fusco, 2020). Ahmedabad is expected to become a megacity of over 10 million inhabitants by 2030 (United Nations Population Division, 2018, p.17). Much of Ahmedabad's urban growth is anticipated to occur through informal construction, which raises complex questions for planners and architects seeking to improve urban housing equality (Dovey & Kamalipour, 2018). In the arid-monsoon climate of Gujarat, planning and design interventions for housing and urban infrastructure are made more urgent by the threats of climate change. Without a major redistribution of resources however, it will not be possible to redevelop, or 'clear', all informal settlements into formal housing to end housing inequality, despite goals and policies by government and non-Governmental organisations which have this as an aim (Government of Gujarat, 2010Gujarat, , 2013Hasan et al., 2005). Policies of in-situ upgrading have therefore become widely accepted as best practice and central to policies put forward by agencies such as UN-Habitat (2016). Consequently, the urban morphology of current and future informal settlements will, in many places, become the permanent pattern upon which the formalising urban landscape is based . To contribute to better decisions about the future of informal settlements, we argue for a deep analysis of residents' experiences of domestic and shared spaces in informal settlements to enable a critical spatial analysis. In this study we reveal the ways in which the built environment can be an asset, or liability, of the urban poor in Ahmedabad.
Informal settlement occurs, when the conditions are right, in many incremental stages that often continue over entire lifetimes and sometimes generations (Turner, 1976). Incremental settlement may be productive, destructive when private interests crowd out common interests, result in 'slum-like' conditions, or result in house upgrading and better living conditions (Kamalipour & Dovey, 2020). Although both rich and poor housing in Ahmedabad is constructed informally, poverty, social status and caste influence the unequal treatment of poor informal built environments in terms of service provision and demolition status (Bahn, 2014;Spodeck, 2011). In India, an informal settlement being granted the legal status of 'slum' recognizes that it is a condition of inequality and allows residents to make claims for infrastructure and services from the state to improve conditions. However, Nolan (2015) demonstrates that divergent 'slum' definitions can lead to conflicting policy priorities and/or underestimating settlement numbers to avoid obligations to remedy conditions, which can further marginalize already disadvantaged communities. Informal settlements, Nolan finds, are more heterogeneous than often assumed, and argues for being aware of definition sensitivities but prioritising better data collection over finding better definitions (Nolan, 2015, p.79).
Improving unequal housing conditions across urban environments relies on more detailed knowledge of informal urban design processes and resulting built forms. Dovey and colleagues argue that, if we want to understand informal settlement as a dominant mode of urban production, rather than conflating it with the term 'slum', we need to engage with how it works as the design and planning of urban infrastructure (Dovey et al., 2021). In this paper we use an architectural analysis of housing inequality to begin to unravel the complex logics of informal settlement and find the physical conditions that may transform substandard living conditions.

Developing an architectural understanding of urban housing (in) equality
We define housing inequality as that which lacks any of the essential qualities of housing adequacy defined by the United Nations within their statement on the Right to Adequate Housing, initially established in the UN Declaration of Universal Human Rights (1948, pp.14-25) and more recently detailed through UN documents (OHCHR/ UN-Habitat, 2014). This stresses that housing "must provide more than four walls and a roof" and "should be seen as the right to live somewhere in security, peace and dignity." (OHCHR/ UN-Habitat, 2014, p. 3) Adequate housing, according to the UN definition, should 1. provide security of tenure; 2. provide essential services, materials, facilities and infrastructure (such as water and electricity); 3. be affordable, meaning housing costs do not threaten the enjoyment of other rights; 4. be habitable, providing adequate space, structural stability and protection from the elements; 5. be accessible, preventing the marginalisation or exclusion of people from housing; 6. be located in proximity to services such as health, employment and educational facilities; and 7. be culturally adequate enabling the expression of cultural identity (OHCHR/UN-Habitat, 2014, p.4). This set of criteria gives the detail which we use to analyse informal settlements with more depth and specificity. We recognize that interventions in informal settlements most often focus on the deficiencies of the built environment and residents, ignoring resident capacity and existing solutions present. We therefore examine housing adequacy, as defined by the UN, through residents' production and adaptation of informal built environments that are in processes of continual change. We identify and examine the factors enabling or hindering residents' agency in the built environment to better understand the way housing adequacy is experienced, and the particular inequalities that residents face, in a resident-centred approach that has been advocated for over time (see, for example, Dayaratne & Kellett, 2008;Usavagovitwong & Posripraset, 2006). Gibson's theory of affordances (1979Gibson's theory of affordances ( /2014, from environmental psychology, offers a useful conceptual framework to describe the relationship between built environments, residents, and housing adequacy with respect to the form, function, and meaning of architectural elements (Maier et al., 2009). Gibson writes that "affordances of the environment are 1 3 what it offers…what it provides or furnishes, either for good or ill." (Gibson, 1979(Gibson, /2014 Gifford explains that Gibson's theory of affordances refocuses attention on the function, or perceived function, of the environment, and is particularly useful in analysing the everyday environment where functions can be taken for granted or wrongly ascribed (Gifford, 2014, p.30). Gifford identifies antecedent factors, and responses, as contributing to how the built environment is experienced (Gifford, 2007, p.195, 214).
We draw on Gibson's theory of affordances to explore how built elements of informal settlements contribute to and/or mitigate housing inequalities experienced by residents. Gifford, Stegg and Reser explain: "People use the physical space among them according to complex rules and strong preferences. Although these rules and preferences are not always conscious, their importance suddenly becomes clear when they are compromised." (Gifford et al., 2011, p.443) We examine the affordances offered in specific housing cases from Ahmedabad, evaluating whether they enable residents to enjoy the criteria within UN definition of adequate housing, or not. This provides a set of specific understandings of how housing inequality is manifested in informal settlements. From existing literature on informal settlements, and other dense urban settings, we understand that both the immediate characteristics of the built environment, and broader societal factors such as public policy, economic and other factors (which Gifford terms antecedent factors) affect what a house, neighbourhood and city afford its residents. For example, the economic context of an urban setting influences what kind of built response is within residents' economic means, and thus is one type of antecedent factor affecting the built environment response. In Table 1 we categorize the UN Housing Adequacy criteria into antecedent factors, and factors which are afforded by the built environment and the design responses which both shape and respond to the informal setting.
We argue that housing which fails to meet any one or more of the above UN Housing Adequacy criteria will be inadequate and the residents described as experiencing housing inequality. Based on these criteria and built environment factors we have identified above, which constitute how they are met, or not, we next explain theoretical frameworks from built environment discourses we use to analyse housing within informal settings, to specifically explore how these housing adequacy criteria are now, and can further, be afforded in the informal built environment.

Location, security of tenure, availability of services and affordability
Despite being the sixth named criterium in the UN housing adequacy list, location is perhaps the most determining element for the creation of an informal settlement. Antecedent factors create a need or desire for housing in a particular location, for example to be near employment, education, healthcare, or other opportunities; and an alignment with what is affordable, when formal housing is not (Barnhardt et al., 2017;Takeuchi et al., 2008). Location is also, we argue, closely linked to criteria 1. security of tenure, 2. availability of services, and 3. affordability, usually determined by location-specific government policies on housing, the application of local regulations such as designation as a slum area with all that may afford or stimy, and other broader antecedent factors (Krueckeberg & Paulsen, 2002;Mahadevia et al., 2014aMahadevia et al., , 2014b. The location of informal settlements are also implicated in determining criteria 4. habitability, 5. accessibility, and 7. cultural adequacy, which are linked to urban form and built environment responses, across the scales from neighbourhood to dwelling. Nevertheless, these three criteria are still influenced by how secure the housing tenure is in that location, the provision of essential services (see for example Teschner et. al., 2020), and what is affordable within that setting.

Habitability
The criterium of habitability (4) has several important contributing elements, including affording personal control, a sense of positive territoriality over a house and immediate surroundings, and structural integrity and protection from the elements. Habitability accounts for which, and when, people share a dwelling, and is critical to feeling safe and secure within one's home (Memmott et. al., 2011, p.11). It is thus not only dwelling size and resident population, but each resident's response and interactions with other residents

. Habitability
Antecedent factors: vulnerability to climate events and other environmental contexts Built environment factors: housing that is structurally sound and meets needs, including adequate for resident population (density), availability of personal control over space (crowding), privacy from co-residents, neighbours and public (territoriality), and adequate protection from elements 5. Accessibility Antecedent factors: urban planning and building regulations ensuring accessibility to neighbourhoods and housing Built environment factors: is built to be accessible, particularly to intended/actual residents. Can include accessibility of the dwelling to the wider urban environment e.g. condition of roads/paths to dwelling 6. Location Antecedent factors: economic context, social factors determining access to neighbourhood Built environment factors: responds to location with design strategies to mitigate constraints and maximize positive affordances 7. Cultural adequacy Antecedent factors: a context of official policy and cultural respect for all members of society who require housing Built environment factors: housing type and design meets cultural expectations and fits with residents' desires on how to live that enables feelings of personal control and absence of related stress. Territoriality is a pattern of behaviour and experience related to control. Gifford, Steg and Reser explain that different forms of territoriality are implemented using both behavioural and physical, sometimes architectural and urban, means.
...territory holders…benefit from a greater sense of self-determination, identity, and even safety. (Gifford et al., 2011, p.444) Territoriality can be architecturally enabled through, for example, the appropriate design of thresholds between public and private spaces. Architectural theorist Herman Hertzberger explains that.
The threshold provides the key to the transition and connection between areas with divergent territorial claims and, as a place in its own right... (Hertzberger, 1991, p.32) To enable habitability, buildings must adequately deal with the local climate and setting. More frequent extreme weather means housing habitability is reducing as more locations face climate change impacts (Williams et. al., 2020). Informal housing often lacks structural adequacy, being built outside regulatory oversight. However, even formal buildings, with building standards applied, can be inadequate where basic infrastructure and social services are not properly considered, housing is mis-matched to the residents or local conditions, suffers from initial poor construction, or maintenance regimes that do not keep pace with wear and tear (Australian National Audit Office, 2010; Rapelang et al., 2018). In informal settlements unsound housing can be used as a trigger for demolitions, often against the wishes of the residents (Gilbert, 2007).

Accessibility
Criterium 5. accessibility, describes housing suitable for residents to enter and navigate, but in self-organized dwellings, accessibility issues are dealt with by residents, whose often very modest dwellings are so basic that they may not pose accessibility barriers. We examine accessibility at the more critical urban scale, afforded by the dwelling's urban context, including access to the wider city through appropriately scaled and maintained roads, affording safe, all-weather passage into and out of neighbourhoods to access goods and services, such as food and medical attention (Kjellstrom & Mercado, 2008).

Cultural adequacy
The final criterium, 7. cultural adequacy, requires analysis of the values and needs of residents. The 'cultural fit' between residents and housing has been the focus of architectural anthropology for many years, with the argument that not only shelter, but culturally appropriate design is needed to afford appropriate spatial arrangements for kin interactions or avoidance (see for example Koch, 2016;Fantin & Fourmile, 2018), cooking of culturally appropriate food (Hage, 2005;Supski, 2006), maintenance of appropriate social interactions including privacy (Altman, 1977;Shaweesh & Greenop, 2020), social networks and obligations (Long, Memmott & Seelig, 2007). This aligns with the UN statement that adequate housing "must provide more than four walls and a roof" stressing that cultural adequacy and "a sense of home" (Dayaratne & Kellett, 2008, p.69) is fundamental.
We argue that by using a combination of an internationally-agreed standard of determining adequate housing, and a specific examination of how housing affords such standards, enables an understanding of informal housing that can better guide specific interventions most relevant to improve housing adequacy, and thus reduce housing inequality experienced by residents of informal settlements.

Method
The analysis of housing adequacy affordances in the informal built environment were derived from Marnane's doctoral research on the physical and social environment of informal settlements in Ahmedabad (Marnane, 2021). Data were collected over 6 months of fieldwork in 2017-2018 from participant observation, shared open space use observation, settlement and neighbourhood mapping, architectural documentation of residents' dwellings, and semi-structured interviews with informal settlement residents using a qualitative case study approach. The semi-structured interviews included questions on the historical trajectory of the incremental growth and responses in built form, which helps to explain how residents have responded to both physical and antecedent affordances, over time.
To accurately record the built forms, we use architectural drawings derived from mobile 3D laser scan data (for documentation method see Zhao, Marnane & Greenop, 2021) analysed together with interview data and observations of spatial use, to describe four residential cases from the perspective of women residents. The architecture and housing affordances from the perspectives of residents are compared to evaluate which spaces support, or inhibit, housing adequacy and how this, in turn, affects experiences of urban housing inequality.

Cases
The four cases are located in three informal settlements as shown in Fig. 1 and exemplify varied combinations of housing adequacy according to UN criteria. The three settlements, Ramapir No Tekro, Panitaka Kutcha Chappra and Gandhi Vas, are in the north of Ahmedabad on the western edges of the Sabarmati River. At a city scale, their location reflects rapid population growth from rural migration, an acute housing shortage, discriminatory policies, and lack of residency rights for low-income workers (McGowan, 2013). Increasing patterns of residential segregation in Ahmedabad emphasize social divides along religious, ethnic, and caste lines and reinforce unequal living standards between different groups (Mahadevia et al., 2014a(Mahadevia et al., , 2014bBalasubrahmanyan, 2011, p.484). Like their surrounding suburbs, Ramapir No Tekro, Panitaka Kutcha Chappra and Gandhi Vas are predominantly inhabited by Scheduled Caste Hindu families.
Each settlement has a different land tenure context and contrasting relationships with the Gujarat Slum Rehabilitation andRedevelopment Policy (2010, 2013). Ramapir No Tekro is a notified slum located on public land owned by Ahmedabad Municipal Corporation and listed for "In-Situ Redevelopment on Public Land (Slums on Public Land)" (CEPT University, 2014 p.127). Gandhi Vas is located on land owned in parts by private entities, the Ahmedabad Municipal Corporation and state government, listed as a "Potential Slum to be Undertaken under PPP Model by Open Bidding (Slums on High-value Public Land)" (CEPT University, 2014, p.125). Panitaka Kutcha Chappra, which translates to 'Houses with Weak Roofs Near the Water Tank,' is not eligible for redevelopment as it is too small to fall under the slum definition of "a compact area of at least 300 population or about 60-70 households of poorly built congested tenements, in unhygienic environment usually with inadequate infrastructure and lacking in proper sanitary and drinking water facilities." (Office of the Registrar General & Census Commissioner, 2013, p.5) In all three settlements, land is informally occupied, and houses are owned or rented by the residents.

Divyabahen's house in Ramapir No Tekro
Our first case is Divyabahen's house at the edge of Ramapir No Tekro in a community called Vadhiyarivas (Fig. 2). 27-year-old Divyabahen lives in a one-room home with an otla (porch) with her husband, 6-year-old daughter and 4-year-old son. Housing inadequacy stems from the environmental precarity of dwelling site, a lack of infrastructure, and insecurity of tenure. Divyabahen's dwelling does not afford habitability because the site is subjected to flooding on a regular basis. A section drawing of Divyabahen's home in Vadhiyarivas in Fig. 3 shows the indicative water line during monsoon as described in an interview.
In a flood event, residents of Vadhiyarivas must evacuate their homes for 10-15 days with only 4-5 hours notice from police. Rebuilding can cost up to 20 per cent of their yearly income, which is saved or borrowed inducing high stress for residents. Divyabahen's dwelling precarity from site flooding is exacerbated by its insecure tenure and threats of demolition from the government, which, in turn, decrease her willingness and ability to upgrade her dwelling to achieve adequate living standards. Divyabahen explained, Factors in the informal settlement that help Divyabahen improve housing adequacy include the location (despite its tendency to flood) which is near more viable livelihoods than in the original village from which her parents migrated, living near schools that provide good education for her children so that they can aim for better-paying employment, living in a housing cluster of extended family, and a shared open space with large shade trees to keep cool. Feeling safe in Vadhiyarivas allows Divyabahen and her family to work, look after children, cook, wash, play and sleep outside, mitigating Ahmedabad's summer temperatures, which regularly exceed 40 °C during the day. Heat conditions are being exacerbated by urban development and climate change, and can reach over 50 °C (Amdavad Municipal Corporation, 2017).
In Divyabahen's case we can see that the antecedent factors of government policy and increasing climate effects, and built environment affordances including an environmentally vulnerable but convenient location, directly feed into this house's lack of ability to meet UN housing adequacy criteria 1, 2, 3, 5, and 6 with only criteria 4 and 7 being met (see Table 2).

Sanyabahen's house in Panitaka Kutcha Chappra
Our second case is Sanyabahen's house across the creek from Ramapir No Tekro in a small settlement of approximately 40 dwellings called Panitaka Kutcha Chappra (Fig. 4). 38-year-old Sanyabahen lives with her two sons aged 22 and 18, two daughters-in-law aged 19 and 18, and one grandson aged 1 in a home they constructed by hand from mud, tiles, bamboo, and plastic. Housing inadequacy stems from a lack of infrastructure, insecurity of tenure and repeated demolitions of her home. Panitaka Kutcha Chappra is located in an easement, and dwellings have been demolished at least twice by government agencies since people started building houses here in 1988. Figure 5 documents Sanyabahen's dwelling constructed with branches from nearby thorny shrubs, bamboo and plastic from the market, and a mud floor finished with found tiles discarded from building sites. She tactically maintains temporary materials so that she can easily rebuild in the event of demolition. Approximately one month's wages are required each year to maintain the mud floor and to replace or patch their plastic roof and walls at monsoon to protect the house from rain, insects, and snakes.   Sanyabahen takes water from valves in the water main running below their site, toilets in the nearby creek bed, and is ineligible for electricity due to their site location in an easement. Factors that help improve housing adequacy include access to education for her grandchildren, living in a community of neighbours with shared values, and a home big enough to share with her two sons and their families. Although Sanyabahen acknowledged she has had troubles living here and difficulties with threats of demolition, access to water and electricity, maintaining hygiene and suffering from mosquitoes, she explained that she does not have money to move elsewhere. Over the 10 years she has lived here, Panitaka Kutcha Chappra has become familiar, comfortable and she likes it. Living in this location affords access to education for her sons and grandson, which supports her aspiration for her family's future to gain better employment through higher education.

If the government does not bulldoze this house again [we] might make this house a bit solid [and more] permanent. But the main thing [we] need is electricity. Without
In Sanyabahen's case the antecedent factors include poor security of tenure which feeds lack of status for provision of services, the economic context of her life, the increase in climate events, and the built environment which does not afford accessibility during weather events. Sanyabahen's built environment does afford UN Housing adequacy criteria of affordability, habitability, location, and cultural fit. In this way, residents are solving a substantial amount of their housing needs through their informal dwelling, despite facing housing inequality as not all criteria are met (see Table 2).

Priyabahen's house in Gandhi Vas
Our third case is Priyabahen's house near the riverbank on the edge of Gandhi Vas (Fig. 6). 30-year-old Priyabahen lives in a rented, one-room dwelling with her husband, two daughters aged 11 and 6, and son aged 4 in a housing cluster built to rent, as documented in Fig. 7. Housing inadequacy results from inadequate income to access affordable formal housing, lack of control over her living situation, lack of infrastructure and a dwelling site in a location she feels impacts negatively on her family, which is exacerbated by her husband spending their money on alcohol and gambling.
Social conditions across Gandhi Vas are not the same, and living near the edge of the settlement, where most of the rental properties are, exposes her family to the activities that occur on the riverbank; namely, drinking alcohol, gambling, and fighting. Priyabahen believes that this environment is contributing to her husband's abusive behaviour and if they were able to save money and move to a new neighbourhood in Gandhi Vas, he would not spend their money on alcohol and gambling and their children would have a better life.

Even if [he drinks, I wish he] could be sensible enough to bring more money into the house…All month [I worry about] saving enough [money for rent]…I really want to move to some place where [my children can learn] good manners…Our life is whatever it is, but [I] want our kids to have a good life…If we move to a good place, my husband also won't do all this…he'll have good things to do in his life. (Interview, Gandhi Vas, 16 March 2018)
The owner of Priyabahen's informal rental property has no obligation to provide a good living environment for their tenants. The property has no toilet, despite there being sewer connections nearby, the shared water pump is unhygienic, and their house is built in the most basic style of one room at the same level as the street, which means that water inundates their home during monsoon and Priyabahen must store her furniture on bricks to keep out of the rain. Work at the nearby community centre helps her earn some money and make friends with women living further in the settlement from whom she can take water.
In summary, Priyabahen's rental home does not afford her family basic needs such as safety from danger, habitability or security of tenure and she is desperate to move elsewhere. The antecedent factors of security of tenure and service provision, once again, are not afforded by this dwelling, and we see how the build environment response does not afford a coping mechanism enabling her house to stay dry or provide sanitary bathrooms. As a result, criteria of habitability, accessibility and a suitable location are not met, and Priyabahen's cultural needs to be near a supportive community and raise her children according to her wishes are also not fulfilled (see Table 2).

Nainabahen's house in Gandhi Vas
Our fourth case is Nainabahen's house towards the centre of Gandhi Vas (Fig. 8). Nainabahen lives in a two-storey dwelling with her husband, daughter aged 23, two sons aged 21 and 19, a daughter-in-law, and a niece. Housing inadequacy results from tenure insecurity. Nainabahen and her husband moved to Ahmedabad in 1998 because they were not getting enough work in their village and her husband needed to support her, their children, and his six sisters if they are ever in need. They lived in three rental houses in Gandhi Vas before they were able to buy a house in 2003, which they have renovated multiple times. In 2018, with seven adults crowded into their two-room house, Nainabahen and her husband demolished and rebuilt their house into three rooms, a roof terrace and front porch over two levels (Fig. 9). Although Nainabahen's husband dreams of living in an even larger house, they do not have the money to go elsewhere. Nainabahen's home affords her family a decent life and she feels happy to have achieved her housing aspirations and is attached to the home that she and her family have invested in over their lifetime.
Nainabahen's home does not afford her family certainty over their living environment into the future because of nearby construction. The Motera Stadium to the north of Gandhi Vas was demolished in 2016 and rebuilt in 2020 as the Narendra Modi Stadium, the largest cricket stadium in the world (Populous, 2020). Architectural illustrations of the masterplan vision show apartment buildings and detached bungalows dotted among large green trees where Gandhi Vas now stands.  Despite the encroaching development and fears that their community will be demolished, Nainabahen and her family aim to continue working towards the life they want. If their house does end up being demolished, their attitude is to deal with issues as they arise and not waste too much time worrying over the future now.
Nainabahen's house meets many more criteria of housing adequacy than other cases, with only the lack of security of tenure not being met. This demonstrates that while she is still facing housing inequality, there are criteria which are helping her to live her life well and this one factor would, from a self-described perspective, lead to an equitable housing situation for Nainabahen (see Table 2).

(In)formal housing (in)adequacy
Comparing each case, Table 2 maps households against the UN criteria for adequate housing. A cross indicates that the household does not afford the criteria, a tick indicates the household does afford the criteria, and a line indicates the household partially affords the criteria for adequate housing. Even with only four cases, the wide variety of housing adequacy in informal settlements becomes apparent, and importantly we see that despite informality and an overall lack of adequacy and persistent inequity in housing, there are built environment factors working for residents in this setting.

Discussion
Analysing the four cases against the UN Adequate Housing criteria demonstrates that informal housing is not always wholly inadequate, in contrast to their settlements' formal 'slum' labels that define them as such. While we acknowledge that complex factors such as economics, climate events, personal skills and agency, and even luck affect the housing adequacy criteria discussed below, we focus on the built environment aspects that support housing adequacy, in line with our concerns to understand this in more detail.
Location, affordability and tenure criteria are directly affected by the dwelling site, which is often a motivating factor for residents, despite other drawbacks related to this criteria, such as proximity to flooding. Habitability and availability of services are also affected by location and in addition, the dwelling design, construction, and ability to upgrade over time. Cultural adequacy and habitability are affected by the ability for residents to manage privacy and who enters their dwelling, which can be controlled through design. Accessibility, availability of services and cultural adequacy are affected by shared open spaces adjacent to dwellings. The discussion that follows focuses on these four key physical spaces-dwelling site, control over dwelling design and construction, dwelling threshold, and shared open spaces-to draw out the role of the built environment in affording housing adequacy at different scales.

Site
Site location is often more important than the dwelling itself by providing access to means of survival in an unequal world. For Divyabahen, Sanyabahen, Priyabahen and Nainabahen, proximity to employment was their primary concern. Secondary concerns were to live Fig. 9 Section of Nainabahen's house over time drawn by Marnane near better education opportunities (Divyabahen, Sanyabahen and Nainabahen), extended family (Divyabahen), and social network (Sanyabahen, Priyabahen and Nainabahen). In the Ahmedabad context, dwelling location near extended family and social networks supports feelings of safety and affords cultural adequacy. Traditional urban and rural settlements follow distinct settlement morphologies of clustered households linked by kinship located in a neighbourhood of similar social groups (Pramar, 1989). The support found within a trusted housing cluster is important for residents' social life, sharing resources, looking after children, and mediating concerns that arise from unsafe dwelling adjacencies. Priyabahen's dwelling, for example, was inadequate largely because of a lack of nearby social support and unsafe dwelling location. Social support is particularly important for women of Scheduled Caste, who face gender, caste, and class-based discrimination and violence, and are often unable to access centralized support services (Raju, 2011;Sabharwal & Sonalkar, 2015).
Site location in undeveloped or leftover parts of the city can, however, result in exposure or vulnerability to environmental conditions and further exacerbate experience of housing inequality, beyond even its normal situation of inadequacy. A dwelling that does not afford safety during regular weather conditions can have significant physical and mental health implications, and can restrict residents' desire or ability to upgrade their dwelling, as we saw in Divyabahen's case. Sites are often small, which can put dwellings at risk of crowding stress, affecting habitability, but are often necessary to achieve economic viability within a condition of poverty. One and two room dwellings with an otla are consistent with low-income formal and informal building norms in Gujarat (Marnane, 2019).
Tenure security is critical for housing adequacy and is the defining factor for housing informality. Residents of informal settlements in Ahmedabad experience a variety of tenures between and within individual settlements, which influence whether residents can access protection from evictions, harassment and access to infrastructure and services, all criteria for housing adequacy. In Ramapir No Tekro, Divyabahen is more vulnerable than neighbouring residents living in established neighbourhoods because she does not have any of the permitted residency proofs that make her eligible for participation in redevelopment processes (Government of Gujarat, 2013, p.5). Gandhi Vas is located on land owned by different actors. Although ownership becomes more informal towards the creek, the relatively consistent architectural character of the area makes defining these tenure change boundaries extremely difficult and demonstrates that informal-formal distinctions do not always result in different architectural forms. Panitaka Kutcha Chappra is too small to be designated a 'slum' settlement and has no tenure security at all, which affects residents' choice of construction materials as they are at constant risk of demolition.

Dwelling design and construction
Constructing dwellings in small increments over time, in the right conditions, can allow poor urban residents to increase the adequacy of their housing. While this does not eliminate housing inequality, it can significantly improve it. Residents have clear aspirations about how their built environment can better meet their most important needs, which is not always housing. Divyabahen aims to invest her family's savings into education for her children rather than improving her dwelling because it often floods during monsoon, which she sees as a waste of precious capital. Housing goals are sometimes secondary to other goals which focus on improving the economic and social status of future generations of the family, which will then include better housing for descendants. Living in Panitaka Kutcha Chappra, Sanyabahen makes small, regular improvements to her dwelling but retains temporary materials to mitigate the risk of demolition due to the precarity of her site and settlement location. Nainabahen has achieved her goal of house upgrading in response to crowding pressure, financial ability, and attachment to the neighbourhood. Upgrading at a household scale for Divyabahen, Sanyabahen and Nainabahen are therefore influenced by site conditions, tenure security, financial capability and crowding. In contrast, Priyabahen, who rents her accommodation, has no control over her dwelling, or its adequacy, which causes her significant amounts of stress. While house upgrading is subject to wider city development and flows of land, finance, infrastructure, building materials and labour (Van Noorloos et. al., 2020, p.50.), these cases tell us that upgrading affords residents the ability to improve their living conditions at a household scale when their finances and site context allows. We argue that that is evidence of significant improvements in overall housing adequacy and reduction of housing inequality where residents have resources to control improvements to their housing, however incremental.

Thresholds
In Ramapir No Tekro, Panitaka Kutcha Chappra and Gandhi Vas, the otla (front porch) is a modest but extremely important threshold that helps residents manage social relations, privacy, and safety between their private indoor spaces and the shared open space of the street. The otla is a space typical across northern India characterized by a change in ground surface height and material to signify the transition between street and house, community and immediate family (Kaza, 2010, p.1). The otla is important in traditional Gujarati architecture as a surveillance position from which to work and participate in neighbourhood life (Pramar, 1987, p.338). Although the otla is open to the street, not everyone is welcome to use it, meaning it creates a territory that is neither completely private nor public (Abraham, 2010, p.200).
Most women residents, including Divyabahen, Sanyabahen, Priyabahen and Nainabahen, rarely leave their home unless they are traveling with family, going to work, to the market, or taking their children to school. Space to build relationships with neighbours is therefore critically important for resident's social enjoyment and mutual economic and social support, and establishes safety through shared knowledge of local community members. Thresholds take on different forms across the cases but all help to build social networks and manage private territory in these dense informal settings. The otla in Nainabahen and Divyabahen's houses is used for chores, working, drinking cups of tea, playing, and socialising. Priyabahen, on the other hand, does not have any otla threshold and she struggles to control a safe dwelling territory. Dwelling thresholds work together with a shared open space at the centre of a housing cluster. This culturally-specific design element is instrumental in establishing housing adequacy within the Ahmedabad context through affordance of both cultural fit and habitability through personal control in the dwelling's territory.

Shared open spaces
Shared open spaces function as the social and cultural heart of the housing cluster in this setting. Women, children, and the elderly in particular use shared open spaces to be part of neighbourly life, where they can simultaneously manage household chores or paid work with watching over children. Shade trees and street paving enhance aesthetics and mitigate 1 3 heat and overland water flow. Clean and beautiful spaces not only have a positive effect on mental wellbeing and improve quality of everyday life (Naukkarinen, 2017), but are a visual indication of territory being maintained, which contributes to feelings of safety (Chakrabarty, 1991;Melchionne, 2013).
To function well, shared open spaces need to be large enough to accommodate circulation of residents and passersby, and multiple additional activities. Narrowing of streets from incremental enlargement of dwellings and subsequent access difficulties is a concern for Divyabahen and Sanyabahen, but can also afford greater privacy in dwellings. In Divyabahen's case, the street within her extended family's housing cluster is of appropriate size, but crossing the creek or accessing streets further into the settlement, which are outside their control, makes passage difficult because of their lack of paving and drainage or small width. A strong social network of neighbours informally agreeing to acceptable development can control undesirable incremental upgrading.
Shared open spaces that are an asset to their surrounding dwellings afford a sense of safety and control and mediate between the scale of the domestic interior, community, and wider settlement. Shared open spaces are distinct from public open spaces because of a sense of shared territory or ownership. A clear spatial territory can be maintained when row-houses are arranged around a shared open space and form a defensive external border. Dwellings with otlas facing shared open spaces affords surveillance and contributes to neighbourly life as domestic activity can spill out from dwelling interiors. Open spaces in this context are a specific, culturally-based response which, despite lack of housing adequacy in other ways, help to satisfy adequacy in habitability, accessibility and cultural fit, ameliorating, but not eliminating, housing inequality when these features are present for residents.
In summary, the assessment of physical space affordances against housing adequacy reveals that some informal settings are a manifestation of inequality while others ameliorate it. Dwelling site location, for example, epitomizes inequality, where informal settlers find proximity to employment and other needs on marginally habitable and sometimes unsafe land, often on very small plots. The environmental precarity of dwelling sites cannot be wholly overcome by resulting buildings, and may be worsened as climate change progresses. Dwelling site is a critical spatial factor in which its governance, immediate socio-spatial and environmental context, wider cultural and political context, and proximity to desirable amenity affect all the essential elements of attaining adequate housing.
A threshold, in contrast, can have benefits in ameliorating inequality. The most effective thresholds in Ramapir No Tekro, Panitaka Kutcha Chappra and Gandhi Vas are simple paved plinths, relatively modest spaces, yet valuable in mediating privacy and providing resident-based control over access to a space between the private dwelling and shared open space, within a shared cultural context governing behaviour. Shared open spaces afford room for residents to work, play and live beyond their small homes. Houses arranged to enclose and survey shared open spaces help contribute to feelings of safety and control because outsiders can be instantly identified, constantly watched and monitored.

Conclusion
Informal settlement occurs, typically in Ahmedabad, through small building increments as a contextual response to physical, social, cultural, and economic conditions of inequality. While our study is limited in scope to four cases, it documents the specific ways in which the built environment of informal settlements can both perpetuate and mitigate these inequalities experienced by residents. Informal housing is, by most definitions, inadequate housing, and therefore inequitable. Yet, the cases presented highlight a variety of experiences within the overarching informal settlement definition, even within a culturally consistent set of cases. In our analysis of the four cases, we demonstrate the ways in which informal housing can be, by UN Housing Adequacy criteria definitions, barely adequate, or very nearly adequate, meaning that different interventions would be appropriate in these different cases. In addition to assessing specifically how houses and neighbourhoods are inadequate and contribute to housing inequality, we also examined the specific built environment responses which contribute positively to housing adequacy where they are present. These four urban spatial settings, namely the site, dwelling, dwelling threshold, and shared open spaces, do not provide complete solutions to the provision of adequate housing, or fully remove housing inequality, but can, in the right conditional combinations, help make housing more adequate and reduce housing inequality.
The design of housing policies, planning schemes and building codes currently lack specific local knowledge about how the built environment contributes to, or alleviates, urban inequality. They lack the detail required to improve specific locations and thus often fail to successfully integrate informal settlements into the wider city. Residents, in contrast to formal plans for their residential areas, have deep knowledge and clear aspirations about how their built environment can better meet their needs. In the right conditions, informal settlement can achieve adequate housing within a context of inequality. Certainly we can say that the housing adequacy achieved in some informal settings may be higher than a demolish-rebuild model where cultural adequacy is often unmet, and difficult to change once the built form has been established. Formal housing, then, is not the only solution to housing adequacy problems faced by governments across the world. However, harnessing the potential of informal settlement requires a better understanding of how informal settlement develops, is maintained, or improved by residents and other actors over time to understand which interventions build on existing solutions that support residents, and which address factors that harm residents further. This study offers a starting point to better understand the built environment affordances within specific informal settlements, and a challenge to further research as to how these multiple layers of knowledge might be put into practice through changed policy, governance, or regulation. Importantly, as evidenced by residents' careful consideration of their own aspirations and family plans, there is a wealth of knowledge about the most pressing and effective factors that would improve informal dwellings and neighbourhoods. Residents' knowledge is rarely tapped by wholesale government upgrading programs. 1 Better understanding of the characteristics of informal dwellings and neighbourhoods, the purposes they serve and constraints residents face, and spatial precedents in other cultural or social settings, is needed in order to plan for future changes to the informal settlement of any location. We argue that conceiving of the existing urban environment, formal or informal, as a critical shared asset of the urban poor, over which they should have meaningful consultation prior to major changes being instigated is a critical step. We do not always need to start with a new built environment, a tabula rasa, when residents have already created solutions that adapt to their challenging circumstances of housing inequality and meet many criteria to satisfy their housing and cultural needs. Housing adequacy, and ultimately the elimination of housing inequality, cannot be attained unless we address the most critical constraints informal settlement residents face, based on their lived experiences.