AbstractThe purpose of this study is to optimize building envelope parameters and ventilation systems by considering passive cooling strategies to improve indoor thermal comfort without any significant supplementary cost in buildings construction and operation in a tropical area. The NSGA-II algorithm is performed in this optimization study using TRNSYS and CONTAM simulation tools, with three objectives: (a) minimization of indoor thermal discomfort, (b) minimization of construction costs, and (c) minimization of the building weight. The results show that the determination of building parameters is highly affected by design objectives. By considering all objectives, the building is recommended to have low-geometry compactness, moderate roof slope, southeast main facade orientation, high roof and wall albedo, and moderate height and wall thickness. However, the final decision to determine the selected building parameters depends on user preferences. The methodology and results in this paper can help design new more comfortable residential buildings in the hot-humid tropical region at more efficient construction cost. It can also improve the energy efficiency of existing residential buildings.