Impact of unassisted expansions on the thermal comfort and air renewal: Case study in Brazilian social housing

Urban transformations have intensified the negative impacts of climate change on vulnerable communities. Social housing (SH) provided by the Brazilian programme Minha Casa, Minha Vida (MCMV) faces challenges with thermal stress and unsanitary conditions due to climatic inadequacies. Additionally, self-built expansions exacerbate these issues by limiting natural ventilation and solar access, leading to thermal discomfort, increased energy consumption and health risks. This study utilized post-occupancy evaluation (POE) techniques, including questionnaires, morphological analyses, walkthroughs and computational simulations to assess the impact of unassisted expansions on thermal comfort and air renewal in Brazilian horizontal SH developments located at Uberlândia city, Minas Gerais state. Findings indicated that 81.05% of participant dwellers experienced heat discomfort, with 43.17% finding ventilation inadequate. Furthermore, indoor thermal discomfort was 15.78% in average higher than outdoor conditions, and air renewal in expanded units was on average 14.9% poorer compared to non-expanded ones. These results underscored the substandard thermal environment quality of horizontal SH units in use, increasing understanding on the correlation between unassisted expansions and their impact on environmental quality. The research benefits from the loop of learning provided by POE instruments performance, providing insights for targeted interventions aimed at improving climate resilience and overall living conditions.