This paper presents the main challenges faced and lessons learned when developing a new method to assess the thermal performance of residential buildings for the recently updated Brazilian building performance standard, NBR 15575–1:2021. It touches on subjects related to the representation of occupant behaviour, climate, and thermal acceptability in building performance simulation, as well as the use of reference models, key performance indicators, and performance levels in policies. NBR 15575 provides a thorough procedure to analyze thermal performance, allowing buildings to be assessed while in passive operation mode and also accounting for energy needs when active operation is necessary. Multiple key performance indicators are introduced to provide a comprehensive evaluation. The main difficulty found was dealing with diversity. Given the vast scale of Brazil’s territory, a high variation in culture, climate and construction techniques is expected, thus requiring a compromise between detail and scalability. There are still many opportunities for improvement, especially regarding the representation of occupants, and adjustments of the characteristics of reference models to promote high thermal performance, considering the diverse climates, regional practices, and economic needs. This paper might help researchers and other stakeholders to develop and improve other local standards and protocols, especially for warm climates.

This study evaluates the effect of urban surfaces’ solar reflectance on the microclimate of a Brazilian city, Balneário Camboriú. A case study of two different geometrical areas of the city's central region was conducted. The influence of solar reflectance was evaluated through computer simulations on the ENVI-met model, validated for a winter and a spring day, according to field measurements. The simulations were performed for twelve combinations of solar reflectance on the roofs, façades, and pavements. The results confirmed that surfaces of high solar reflectance generally contribute to an air-temperature decrease. However, the degree to which each surface's solar reflectance influences the air temperature depends on the solar access (urban geometry, time, and season). In denser areas, the solar reflectance of facades has a greater impact on temperature variation, whereas in open spaces, roofing and paving surfaces are more critical. Impacts on urban microclimate extend beyond air temperatures. The radiation fluxes on two urban canyons revealed that the solar radiation incidence on the paving of a high solar reflectance canyon could be up to three times greater than one with low reflectance.