Greening construction processes using an input-output-based hybrid life cycle assessment method

This research uses a life cycle assessment (LCA) framework to create a more specific and accurate estimate of the environmental impacts of construction processes. The construction industry is spatially and economically diverse, yet fragmented because of it depends on various specialized contractors, is always changing, and is occurring everywhere. Because the construction industry is so complex, modeling construction processes is required in order to better understand the specific environmental implications of these activities; this goal would be best achieved with the process LCA approach, though process LCAs are data intensive and time consuming given the unique nature of every construction project. Conversely, the input-output (I-O) LCA approach allows for a more inclusive view of the construction industry (i.e., on-site construction activities and its supply chain), which can be used to identify processes of principal concern. A combination of both approaches allows capitalization on each method's strengths. Consequently, a hybrid LCA framework produces a comprehensive analysis that includes the economy-wide effects of construction while addressing on-site construction activities.; The I-O-based hybrid LCA framework selected for this research is based on Carnegie Mellon University's (CMU) Economic Input-Output Life Cycle Assessment (EIO-LCA) modeling tool. The I-O-based hybrid model was created by combining a new "Hybrid" feature that uses the EIO-LCA interface with updated and reformulated environmental effect vectors for EIO-LCA's thirteen construction sectors. The final stage of this research models a variety of construction case studies on the I-O-based hybrid LCA framework; these case studies demonstrate the model's broad applicability and which environmental impact categories significantly increased with the hybrid framework (e.g., gasoline, particulate matter, and global warming potential). The I-O-based hybrid LCA model for construction is intended to help decision-makers make more informed decisions regarding the construction industry, adding environmental quality and sustainable development as goals instead of unintentional benefits. The model's focus on construction site and supply chain activities helps identify improvement opportunities that may otherwise be missed; it also provides a holistic assessment that identifies priority areas for future research regarding construction's environmental impacts.