This paper proposes a computational building design support framework. The framework evaluates and optimizes building envelope systems, electrical systems and HVAC systems simultaneously with the assistance of a newly developed EnergyPlus component cost database. The integrated building system evaluation could potentially reveal the trade-offs among different building systems and help clients and design teams a gain better understanding of high performance designs.

A case study based on a real office building is presented to demonstrate the effectiveness of this framework. EnergyPlus v8. 3 was used as the building performance evaluation tool. The NSGA-II multi-objective optimization algorithm was employed for acquiring the best design combinations. Results obtained from the optimization process proved that buildings with high performance components will present savings for both first and operation costs. Trade-offs between the first cost and operation costs for different designs were also discussed within five selected optimized cases.