Sustainability Performance of Green Building Rating Systems (GBRSs) in an Integration Model

In most countries, more than one green building rating system (GBRS) is available on the market. Because of their different approaches, it is difficult to confirm which system can respond to sustainability requirements better. A building considered to be “green” by one Green Building Council (GBC) may fail to satisfy the requirements set by another council. The aim of this study is to evaluate the sustainability performance of GBRSs and establish an integrated model of multi-certification for optimal sustainability. A direct content analysis method was utilized to evaluate GBRSs’ qualitative performance using the ISO sustainable building standards. In this study, seven purposively selected multi-certified buildings were evaluated, and an integrated model was proposed as a better mechanism for the multi-certification process. The proposed integrated model contributes to the achievement of sustainability indicators. The model was implemented on case study buildings, and the proposed combination shows better sustainability performance than existing practice. The developed model helps practitioners in their selection of GBRSs in the multi-certification process. In addition, the performance evaluation of GBRSs will support the future update of GBRSs. The qualitative performance evaluation was performed considering mandatory requirements and prerequisite and credit requirements of selected rating systems, making the work a stronger approach than previous studies.