Roof Optimization of Three Floor Residential Building Using G.ACase Study: Shiraz, Iran

Among the components of the building envelope, the roof section is the most important medium of energy loss, because, compared to vertical walls, a larger area of the rooftop is exposed to sunlight and atmospheric condition for a longer period, which results in greater heat exchange through this section. The goal of this research is to reduce the energy consumption of residential buildings in the city of Shiraz (Fars, Iran) through the optimization of their roof sections by answering the bellow question:”What is the most optimal combination of materials and passive roof design technique for reducing energy consumption in this climate and how much will it reduce energy consumption?”The purpose of the research, which is to identify the best combination of roof specifications and passive design methods for minimizing energy consumption in the buildings of the area of interest, was achieved with help of the EnergyPlus simulation and a genetic algorithm developed in MATLAB. The roof variables were defined in three categories of the passive energy system, physical roof specifications, and positioning and the optimization was carried out using the genetic algorithm and the EnergyPlus software. The outputs obtained from the simulation software and the objective function of the genetic algorithm showed that the roof optimization models could reduce the energy consumption of the building by 39-50%