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.