Occupants' adaptive behaviour and thermal perception in social housing buildings in Brazil

Social housing is often not well designed nor fit-for-purpose, delivering poor indoor environmental quality conditions, especially thermally, to occupants. This situation is often worsened by occupants' limited capacity to adapt their surroundings and to cope with heat exposure. Considering the increasing number of extreme heat events and the likely vulnerability of social housing occupants, further research is needed. This study addresses this knowledge gap by examining occupants' adaptive behavioural strategies, thermal perceptions, and the key factors shaping subjective thermal responses in four social housing developments in hot and humid regions of Brazil. A mixed-methods approach was adopted, combining indoor environmental monitoring, interviews, and a thermal comfort survey, with 103 participants. The analysis revealed sustained exposure to high indoor temperatures (>25.24 °C), particularly during summer, when mean operative temperature is 31.22 °C. During this period, most occupants reported warm and hot thermal sensations (69.35%) and a preference for cooler conditions (85.48%), suggesting difficulties in cooling indoor spaces under prevailing conditions. To analyse whether variables beyond the physical environment — including socioeconomic conditions, residential experience, and behavioural aspects — were associated with occupants' thermal responses, logistic regression models were developed. The results revealed that thermal sensation was significantly associated with operative temperature, relative humidity, age and patterns of fan use, while thermal comfort was associated with a broader range of predictors, including residential experience variables such as perceived safety and length of residence. While acknowledging the limitations associated with the sample size, these findings contribute to the development of more integrative approaches to thermal comfort assessment that incorporate social, psychological, and behavioural dimensions.