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In the last few years, the design community has embraced the challenge of reducing embodied carbon in buildings. Several tools are now available for comparing materials and assemblies in the structure and enclosure from the standpoint of product-stage greenhouse gas emissions. However, most tools do not provide sufficient information for designers to be able to compare façade cladding and exterior shading materials and assemblies – two pieces where architects have the most control in terms of product selection. Authors of this paper at Atelier Ten identified this as a research gap, and performed embodied carbon-focused comparisons of material alternates for these applications across several large-scale commercial construction projects in the Bay Area.
Material options included terracotta, aluminum extrusions, cementitious composites like fiber-cement, ‘extruded' glass-fiber reinforced concrete (GFRC) and ultra-high performance concrete (UHPC), fiber-reinforced plastic, and wood. Environmental impact data for these was obtained from a combination of product-specific Environmental Product Declarations (EPDs), industry-wide EPDs, LCA studies published in academic journals, and data from manufacturers. Cementitious composites like UHPC were found to be the option with lowest embodied carbon for both cladding and shading applications.
Furthermore, noting that the enclosure can make up 20-30% of the total embodied carbon of a building, with about half of that coming from aluminum, the authors studied the embodied carbon origins of aluminum. Aluminum extrusion’s embodied carbon is high variable, being dependent on its sourcing location’s electricity grid mix, the proportion of primary and secondary billet, and its finish coating. Designers are recommended to specify aluminum from hydro-powered grid regions, with high recycled content and anodized finishes. Manufacturers are recommended to provide 'green' product lines for project teams are seeking sustainable aluminum, while the industry works towards reducing GHG emissions as a whole.
Finally, exterior shading was evaluated from the lens of a 'carbon investment'. The authors found that even in conservative scenarios, performative shading would 'pay back' its initial embodied carbon through operational carbon savings in less than 5 years - making it a sound design choice for most US projects.
This section describes the significance of embodied carbon as a challenge for real estate sector and how the AEC industry has been responding to it. Tools used by building professionals to understand and reduce embodied carbon are discussed, and a research gap relating to façade components is identified, which serves as the primary motivation for this paper.
“Buildings contribute to nearly 40% of global energy-related greenhouse gas emissions” – this is perhaps the most-quoted statistic by practitioners of sustainability in the built environment. Numerous scientific studies and
This section summarizes key lessons learnt by the authors about the embodied carbon of facades through the Atelier Ten’s collective experience and institutional knowledge about the subject. These lessons are
This section details the objectives, analysis methodologies and results of the three studies framed at the end of the preceding section.
Atelier Ten worked with architects and enclosure
The three most important takeaways from this paper are listed here:Building enclosure can make up 20-30% of the total embodied carbon of new construction buildings, with much of it
Our colleagues at Atelier Ten who helped with various pieces of the analyses presented in this paper.
 IPCC, 2018: Global warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [V. Masson-Delmotte, P. Zhai, H. O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J. B. R. Matthews, Y. Chen, X. Zhou, M. I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, T. Waterfield (eds.)]. In Press
 IPCC, 2021: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press. In Press
 Waldman, B., Huang, M., & Simonen, K. (2020). Embodied carbon in construction materials: a framework for quantifying data quality in EPDs. Buildings and Cities, 1(1), 625–636.
 Carbon Smart Materials Palette, Architecture 2030. Accessed via https://materialspalette.org/i...
 Sustainability section, Kreysler and Associates Website: Accessed via http://dev1.kreysler.com/information/sustainability/
 Aluminum Industry Environmental Product Declarations, Aluminum Association Accessed via https://www.aluminum.org/sustainability/environmental-product-declarations
 Aluminum Extrusion Environmental Product Declarations and Lifecycle Assessment, Aluminum Extruders Council website. Accessed via https://www.aec.org/page/extrusion-sustainability-epds-lca
 DiStefano, K., Richardson, H. (2019). The Future of Carbon Neutral Design. Accessed via https://www.atelierten.com/app/uploads/2019/07/Carbon-methodology-paper-190724.pdf