Research on green renovations of existing public buildings based on a cloud model -TOPSIS method

Energy saving and consumption reduction in the field of public buildings (PBs) are keys to achieving the target global temperature growth of the Paris Agreement. However, evaluations of the green renovation (GR) of existing PBs are challenged by the need to construct a unified dimensional model for renovations that are convenient, durable, resource saving and environmentally friendly. This paper proposes a TOPSIS decision method based on a cloud model for the evaluation of GR schemes of existing PBs that can overcome the ambiguity and complexity of scheme selection. The method and preparation processes are described, and the qualitative concepts and boundaries are defined. Then, evaluation models of GR for existing PBs that comprise energy savings and energy utilization, water savings and water resource utilization, land savings and both the outdoor environment and indoor environment are established. An integrated assessment is performed to identify the best plan for GR, and the corresponding evaluation indexes are determined. Finally, a case study in the main library of Huazhong University of Science & Technology (HUST) is examined. The most suitable scheme for the case study is to expand the library by connecting the vacant land space between Yifu Library and the old library. This case study illustrates the validity and practicability of the proposed method, laying a foundation for the selection of GR schemes.