Sustainable Design of Residential Net-Zero Energy Buildings: A Multi-Phase and Multi-Objective Optimization Approach

Zero energy building (ZEB) is an important concept for sustainable building design. This paper introduces a holistic design approach for residential net-zero energy buildings (NZEB) by adopting the Triple Bottom Line (TBL) principles: social, environmental, and financial. The proposed approach optimizes social need by maximizing thermal comfort time of natural cooling, and visual comfort time of daylighting. The environmental need is addressed by optimizing energy efficiency, and the financial need is addressed by optimizing life cycle cost (LCC). Multi-objective optimizations are conducted in two phases: the first phase optimizes the utilization rate of natural cooling and daylighting, and the second phase optimizes energy efficiency and LCC. Sensitivity analysis is conducted to identify the most influential variables in the optimization process. The approach is applied to the design of a landed house in a tropical country, Singapore. The results provide a framework and modeled cases for parametric design and trade-off analysis toward sustainable and livable built environment.