Environmental performance of a cross laminated timber (CLT) building system with a focus on carbon footprint

Abstract: The global construction industry accounts for more than 30% of the energy consumption and 40% of the carbon dioxide emissions, and roughly 60% of raw material extraction. A cross laminated timber building system is one solution to reduce the construction industry's environmental impact, particularly carbon footprint. Evaluating the potentials to reduce the environmental impacts of such a building system is the aim of this study. Life cycle assessment (LCA) is a comprehensive method to evaluate the environmental impact of buildings and is applied in the thesis. The environmental impacts analyzed in this thesis comprise global warming potential, acidification, ozone layer depletion, eutrophication, formation potential of tropospheric, and abiotic depletion potential. Firstly, the environmental impacts of the reference building are calculated based on environmental product declaration (EPD) through production and construction phases (A1-A5 module) of LCA; next, the transportation phase (A4) modified, and finally, the environmental impacts are analyzed based on the lowest available global warming potential figures. Reference building results show that global-warming potential, eutrophication, and abiotic depletion potential accounted for 182kgCO2-eqv / m2, 0.169 PO4 3-eqv / m2, and 0.003 kg Sb-eqv / m2, respectively, and figures decreased on an average of 40% for improved building. According to the outcomes, decision-makers should regulate material selection based on the lowest possible carbon footprint and energy consumption for the construction permission of the buildings that will be built in the future.