The traditional methods for the evaluation of the thermal performance of buildings are appropriate to winter conditions and are often used in standards that regulate energy consumption. However, they are not adequate to the evaluation of the thermal performance of buildings in tropical climates, predominant in Brazilian territory. These questions are discussed in this paper, where a method is presented for the evaluation of the thermal performance of buildings in Brazil. The evaluation criteria used in this method impose the application of detailed simulation software that is able to determine in reliable way the dynamic thermal behavior of the building.