Embodied Carbon Impacts of Building Envelope Systems

Abstract

Abstract As buildings become more energy efficient due to stringent building codes, the emphasis on reducing the embodied carbon (EC) in the built environment has become significant. Studies predict that between 2020 and 2050, new buildings will surpass operational emissions with higher embodied emissions in their initial decade and throughout their life cycle. To meet decarbonization targets, reducing EC through low-carbon, high-performance building designs and grid decarbonization is crucial. This research analyzes the embodied carbon intensity of 26 commonly used envelope systems of large buildings in Ontario’s Greater Toronto and Hamilton Area (GTHA) using the attributional life cycle assessment (ALCA) methodology. Results highlight the impact of cladding materials, insulation layers, and backup structures on EC. The study ranks envelope assemblies based on their EC intensity (ECI), providing insights for designers to balance operational and embodied emissions. Noteworthy findings include the relatively high ECI of floor systems compared to exterior wall and roof systems. It also emphasized the challenges in assessing the environmental impacts of wood-based products and the need for uncertainty analysis and transparent reporting. The study contributes to understanding EC in building envelopes, guiding design teams toward low-carbon structures and more informed decision-making. As research progresses, recommendations include consequential analysis, assessing biogenic carbon impacts, and material durability studies for a deeper insight on the environmental impacts of building envelope materials.