Example of a Hybrid Life-Cycle Assessment of Construction Processes

Design and construction industries, along with owners, have an increasing interest in and responsibility for the environmental impacts of buildings. Since the environmental impacts of a building's life cycle are considerable, quantification of all phases is important, especially the construction phase, which is often glossed over. This research focuses on the construction phase of a building project. Generally, the life-cycle inventory created in performing a life-cycle assessment (LCA) is developed using either a process or input-output approach; however, both techniques have distinct advantages and disadvantages. A hybrid approach combining both methods' advantages has been proposed and will be demonstrated. Existing hybrid models are reviewed, along with a recommendation of a hybrid model for construction. A preliminary case study of a precast concrete parking garage's construction using hybrid LCA methodology is presented. Preliminary investigations indicate transportation, equipment activity, and support functions have the largest effects on the environment.