Using life cycle assessment to derive an environmental index for light-frame wood wall assemblies

Following a life cycle assessment (LCA) approach, this study aims at defining an appropriate performance index to consider environmental impact in the development of a multicriteria evaluation comparing factory-built wood-frame exterior walls. The investigation is applied to a case study comparing five wall assemblies for the exterior wall of a residential building in Quebec City (Canada). For the five alternatives, the life cycle inventory (LCI) provided by the ATHENA™ Environmental Impact Estimator software is aggregated using three different life cycle impact assessment (LCIA) methods: IMPACT 2002+, Eco-indicator 99 and TRACI. The relative impacts of assembly components and of the operation energy source on the environmental performance of the assemblies are investigated by comparing midpoint and endpoint indicators calculated with the three LCIA methods. The study concludes to the acceptability, in this specific context, of using the climate change indicator as an appropriate environmental index.