The Brazilian NBR 15575 Standard: House-building performance (ABNT, 2013) represents a significant step forward for the Brazilian construction industry. It is important to keep an on-going discussion about its methods in order to encourage its improvement. Some authors have criticised the methods established by that standard, pointing to inconsistencies between the simplified procedure and the simulation procedure. This study investigates the reasons for these inconsistencies, focusing on social housing. The research method consisted of the application of both procedures on a single-storey house located in three Brazilian climate zones, with distinct envelope U-values and absorptancy. Simulations for the house whose walls have high thermal capacitance were also performed, as well as annual simulations for the building in normal use conditions. The results showed that the joint impact of the U-value and absorptance is not adequately represented in the simplified method. It was also observed that thermal capacitance influences these limits. The annual simulation proved to be the best way to evaluate different performance requirements in the summer and winter.
NBR 15575; Thermal performance; Simplified procedure; Social housing
