Life cycle assessment of housing and neighbourhoods: A systematic review

Housing accounts for a high proportion of our anthropogenic greenhouse gas (GHG) emissions and represents a large environmental footprint, particularly when supporting infrastructure and transportation are included. This review introduces three housing life cycle assessment (LCA) frameworks, which are distinguished by the spatial scope of analysis and built environment elements included. The choice of housing LCA framework has possible tradeoffs affecting the environmental impact quantification and selection of lower impact housing built form or housing development type. The objective of this systematic review is to compare previous standard housing LCAs, holistic housing LCAs, and neighborhoods LCAs related to the four stages of LCA (goal and scope definition, life cycle inventory, impact assessment, and interpretation). This paper presents quantitative analyses of housing GHG emissions from the reviewed studies which indicate that standard housing LCA underestimates average GHG emissions by 43 % due to exclusion of mobility, and by 11 % due to exclusion of open spaces, and networks. The interpretation of which housing built form has lower GHG emissions switches between standard and holistic housing LCAs. This review recommends the use of holistic housing and neighborhood LCAs to fully assess the environmental impacts of early-stage housing and neighborhood planning. However, these frameworks require standardization, including functional unit definition, scoping of system boundary, and treatment of temporal uncertainty and variability in housing contexts.