Environmental performance-oriented approach proposal in building material selection for a green building certificate

With the adoption of sustainable construction strategies in the construction industry, the selection of sustainable building materials has created a new decision problem. Within the scope of this study, a life-cycle assessment (LCA)-based selection approach is proposed for environmentally sustainable building material selection. The proposed approach consists of two modules. In the first module, the building materials in the selection problem are evaluated among themselves in terms of their environmental performance and ranked according to their evaluation scores. In the second module, the conformity assessment of the material chosen by the decision maker to the LEED (Leadership in Energy & Environmental Design) green building rating system is checked and a preliminary evaluation of the score is made. LCA is implemented according to an internationally accepted methodology. The results of the application differ depending on the space and time where LCA studies are carried out. For this reason, it is necessary to make regional adaptations in LCA applications. In the study, twelve environmental impact categories accepted in the literature were taken into account in the sustainability evaluations of building materials. The opinions of green building sector stakeholders in Turkey were consulted in determining the relative importance of environmental impact categories. AHP technique was used to determine the weights of environmental impact categories based on semi-structured interview results. Inventory data within the life cycle of the building materials included in the selection process were taken from the BEES (Building for Environmental and Economic Sustainability) Online database. While calculating the normalization values of the environmental impact categories, the standards and the legislation in force in Turkey, the work of the ministries, emission measurement data and the data of the Turkish Statistical Institute were taken into account. By using the material selected through the proposed approach in the building, the potential to gain points from the LEED green building rating system is determined by calculating the credit success rates. The scorecards of forty-seven buildings with LEED green building certificate in Turkey were taken into consideration as reference information when comparing loan credit achievement degree. Reference information on the LCA processes of the comparison materials was obtained from the literature review. The proposed approach framework is tested on a scenario. When the construction material selection was made within the scope of the proposed approach, it was observed that three of the six LEED credits evaluated in the study improved the credit achievement degree. While the approach presented in the study will guide the selection of sustainable building materials, it will also be effective in the selection of suitable materials for buildings with the goal of obtaining LEED green building certification. In the presence of many green material alternatives, it will facilitate the decision-making processes of decision makers.