Life Cycle Analysis of Three-Story Mass Timber and Reinforced Concrete Structures

Abstract Sustainability initiatives in the construction industry are steadily growing due to the negative impacts of the conventional materials used in this sector. Employing more environmentally friendly materials like mass timber based on its availability in the region, geographical weather conditions, existing technologies, and policies has gained research interest in industry and academia. Previous work exploring the environmental impacts of mass timber structures highlighted specific aspects of building life cycles, including material sourcing and transportation, while failing to discuss structures built with alternative materials. A cradle-to-grave comparative life cycle analysis was conducted for three-story mass timber and reinforced concrete structures in the Pacific Northwest. An open-source life cycle assessment (LCA) software (openLCA) was utilized to evaluate the environmental impacts, with input data and process models from the openlca_lcia_methods database. Mass timber components as an alternative to reinforced concrete exhibited lower impacts on global warming potential, terrestrial acidification, and human carcinogenic toxicity. Utilizing mass timber demonstrates a 33% decrease in greenhouse gas emissions (GHGs). Future advancements of this work will employ a more comprehensive LCA tool, database, and method to explore substituting other renewable and biobased materials for non-load bearing applications to evaluate and improve the sustainability performance of building structures for commercial and residential applications.