Daylight challenges in Brazilian social housing: lessons from recent standards

This study assesses the daylight performance of Brazilian social housing according to the proposed Section 13 of NBR 15575-1 and the design requirements introduced by Ordinance MCID No. 725/2023. Two building typologies were analyzed in three cities (Cuiabá, Florianópolis and Recife) through annual climate-based simulations, considering variations in surroundings, topography and solar orientation. Two scenarios were assessed: a pre-ordinance baseline and a post-ordinance configuration implementing the prescribed requirements. The research introduces an innovative methodological framework that integrates architectural and urban variables to explore how regulatory design criteria influence daylight availability. An open-access Power BI platform was developed to explore simulation data. Results showed that the living rooms of post-ordinance buildings had more non-compliances with the standard, particularly on lower floors and denser surroundings. Sloped terrains increased shading effects, while latitude and cloudiness amplified intercity differences. The findings indicate a mismatch between regulatory parameters and daylight performance, particularly for the minimum spacing between buildings prescribed by the ordinance. The study highlights the need to revise standards and integrate complementary architectural strategies to ensure adequate daylight availability in future social housing developments.