A bi-objective optimization of energy consumption and investment cost for public building envelope design based on the ε-constraint method

Abstract

As a basic part of building energy-saving designs, the design of the building envelope provides an opportunity to achieve sustainable development goals. However, it is not comprehensive to blindly pursue the lowest energy consumption when optimizing design schemes. In this case, it is of great research significance to build a fast and efficient optimal model to balance different objectives. A bi-objective integer programming optimization model is proposed to minimize energy consumption and investment costs based on the analysis of the architectural and social environments in which public buildings are located. The key parameters of the building envelope are thus identified on this basis, and a variety of optimal design schemes that consider investment cost and energy consumption are designed. The model is then implemented in AMPL equipped with the CPLEX solver and solved by the improved epsilon-constraint method. Finally, a real-world case study in Qingdao is taken to validate the developed model, and the resultant Pareto frontier is evaluated to prove the trade-off between objectives. The results show that the proposed model effectively reduces building energy consumption and investment costs in the design stage. The comparison with other algorithms proves that the proposed method has good search and optimization capabilities. This study can provide a quantitative reference standard for public building designers in the design phase, coordinating economic and energy-efficiency optimization.