Comprehensive assessment of embodied environmental impacts of buildings using normalized environmental impact factors

Buildings are responsible for many environmental issues during construction. Although many studies have evaluated buildings' life cycle embodied environmental impacts (LCEEI), the difference in units usually results in isolation and separation of impact assessments. Assessment results of different indicators and environmental issues often cannot be compared with each other. This paper proposed a building LCEEI evaluation approach by integrating building information modeling (BIM) and life cycle assessment (LCA). In the proposed approach, 24 environmental impact factors (EIFs) from the cradle to the grave are firstly calculated and then linked to 10 building-related environmental issues. The comprehensive assessment of embodied environmental impacts is conducted with a three-step normalization process, including characterization, nondimensionalization, and quantitation. A reinforced concrete structure building is selected as a case to demonstrate the proposed approach. The case indicates that mineral resource consumption, timber consumption, and fossil fuel consumption contribute the top 3 largest proportions (over 80%) to the LCEEI of reinforced concrete structure buildings. The material production stage is the most crucial stage to improve a building's environmental performance. Concrete, steel, and timber are the top 3 materials generating the most EIF. The study enriches the knowledge of sustainable construction by proposing a BIM-LCA integration approach to comprehensively evaluate the LCEEI of buildings at the design stage.