Office Building Envelope Design Optimization by Modified Competitive Search Algorithm for Energy Saving

35 Building envelopes for green buildings should be designed with low energy consumption and low 36 construction costs. A modified competitive search algorithm is used for the optimization of the office 37 building design due to the long runtime of simulation tools such as EnergyPlus and TRNSYS. For the 38 minimization of the cost of construction at the needed energy conservation, the envelope configuration, 39 such as window numbers, walls, glass curtain walls, etc., is optimized. Comparing the proposed algorithm 40 with some others, the cost decreased for the optimum design of the building structure at the needed energy 41 load value. The number of iterations is also reduced by the proposed approach. Moreover, the overall area 42 of the window is increased, which has resulted in the natural ventilation being more proper. Since the ratio 43 of the glass curtain wall is increased, it can result that the indoor lighting being better. Per unit area of the 44 envelope, the value of the energy load is smaller and the total cost is lower for the proposed method in 45 comparison with other algorithms, considering that the opening rate of the window is much the same. The 46 total cost decreased by 37.1% in comparison with the initial design. It can be observed that the MCSA is 47 more efficient than the other compared methods in energy saving of the building in this paper. 48