Objectives: The study investigates the relationships between physical attributes of communal open spaces and spatial behaviour, in order to measure to what extent quality of communal open spaces supports community formation across different dwelling types in low-income housing schemes as a means to achieve social sustainability. Context and background: Performance evaluation of housing schemes implemented in Brazil show differences on environmental quality and possibilities of appropriation, with frequent neglect of communal open spaces, both in terms of physical and social performance. A body of research indicates that most of the qualitative problems that affect performance of housing schemes are originated by inadequacy of site layout and dwelling design, limiting performance and affecting use opportunities and community formation. Methodology: Methodological procedures consisted of post-occupancy evaluation of twelve housing schemes, comprised of four storey blocks of flats, terrace, detached, semi-detached and row houses, located in the metropolitan region of Porto Alegre, Brazil. Data was collected through questionnaires, interviews, observations and physical measurements. Findings and Conclusions: Correlation between type and intensity of relations among residents, satisfaction with the scheme, and satisfaction with the living environment indicate that the better are relations among residents, the higher is satisfaction with the scheme and the living environment, and vice-versa. Residents of detached, semi-detached and row houses are better related among themselves than residents of blocks of apartments and terrace houses. Relations among residents and sense of community affect level of maintenance of communal open spaces and equipment: the better are the relations, the better the community is organised for provision and upkeep of buildings and communal open spaces. The lack of organisation and maintenance in the scheme highlights problems among residents, and indicates the impact of physical characteristics on sense of community, further affecting social sustainability within the housing schemeApplicability to the field: The paper is based on selected results of a comprehensive research supported by the National Financial Institution responsible for the production of low-income housing schemes in Brazil, carried out with the purpose of gathering feedback information to provide design guidelines for future housing production