The influence of the prefabricated rate on the environmental performance of buildings in a life cycle perspective

Sammanfattning: As the construction sector has caused significant environmental impacts, Sweden has made efforts to develop prefabricated buildings by increasing their prefabricated rates. In a life cycle perspective, this thesis examines how the overall environmental impacts during the construction processes are influenced when the prefabricated rate increases. By modelling in SimaPro version 9, this thesis conducts a life cycle assessment (LCA) of a concrete framed reference building with a prefabricated rate of 26% located in Stockholm Royal Seaport. Nine scenarios with increasing prefabricated rates varying from 6% to 96% are compared in the thesis. The results show that when the prefabricated rate increases, the total water consumption of the building is optimized, while the overall energy consumption and GHG emissions have increased. For other environmental impacts, the thesis finds the terrestrial ecotoxicity is the most affected impact category when the prefabricated rate rises. The thesis indicates that water consumption of the building is mainly influenced by material extraction and processing stage, and the transport is the dominating factor to energy consumption, GHG emissions and terrestrial ecotoxicity as the prefabricated rate rises. The sensitivity analysis in the thesis also reveals that the energy consumption and GHG emissions of the prefabricated building are sensitive to transport scheme, such as transport distance and vehicle types.