Benchmarks as a tool for free allocation through comparison with similar projects: Focused on multi-family housing complex

A multilateral effort to reduce greenhouse gas (GHG) emissions has been implemented around the world. In particular, the Emissions Trading Scheme (ETS) emerged as a market-based approach used to control GHG emissions by providing carbon credits (or allowances). One of the most controversial issues in the ETS is the question of how the allowances will be distributed. Therefore, this research aimed to develop a decision support model for establishing benchmarks as a tool for free allocation in the construction industry. It can be used in the pre-design phase to estimate the amount of allowances in a given construction site. In this study, a total of 147 types of data on the reinforced concrete frame in multi-family housing projects in South Korea were collected and used to develop the advanced Case-Based Reasoning (CBR), which can be used to establish benchmarks as a tool for free allocation.Results showed that the prediction performance of the advanced CBR model was superior (prediction accuracy; standard deviation) in all classifications: concrete (93.45%; 6.01), steel bar (94.20%; 4.34), and formwork (94.28%; 4.67). In the case study, a total of 60 possible combinations were evaluated in terms of the economic and environmental impact simultaneously with the retrieved cases. The results of this study could be expanded into other areas including new renewable energy, rehabilitation projects, and demolition projects.