Designing buildings with the lowest possible cost base is an essentiality in sustainable architecture. Previously, due to the computational complexity of building's energy consumption, the environmental impact on thermal and lighting energy consumptions haven't been considered simultaneously. As non-linear relationships are often disclosed, a comprehensive approach is necessary to reduce the total energy need of a building and optimize the façade configuration at the same time. Solar radiation affects thermal and lighting energy consumption which depends on building fabric’s characteristics. In this paper a parametric method to optimize the window size and sunshade dimensions of an educational building in mild climate of Iran is presented. Through integrating thermal and lighting energy consumption, 6750 window and sunshade configurations are studied and compared. First, climatic parameters and thermal analysis are validated by on-site measurements. Then, the characteristics of the simulated model and all thermal and lighting parameters have been defined. Finally, the best solution is optimized through genetic algorithm. The results show that, in the first phases of the design process building’s characteristics should comply with national code regulations and then components of the building will be optimized. Additionally the horizontal windows with higher sill levels are more energy-efficient in classrooms.
