Life cycle assessment as a research methodology for estimating the environmental impacts of buildings

The growing concerns about the embodied environmental impacts of buildings have led to the increased application of life cycle assessment (LCA) methodology in the built environment research. The present chapter first compiles and presents an overview of the environmental flows of the U.S. building stock in several categories including operational energy use and carbon emissions, embodied energy and carbon, consumption of materials (such as cement, steel, timber, and copper), and generation of construction and demolition solid waste, and highlights the knowledge gaps to be bridged. It then provides an overview of life cycle assessment (LCA) methodology in architectural research, followed by an example of its application by the authors. The chapter then demonstrates the application of optimization and data-driven techniques in building LCA research. It also presents some of the challenges in the LCA research including result uncertainty. Finally, a standard reporting framework is proposed to fill the gap in the literature and practice regarding inconsistent and insufficient reporting of LCA methodological assumptions and results.