Assessing whole life carbon impacts of retrofitting Canada's 19th and early 20th century homes towards net-zero.

Mancini, A.; Sedikki, M.; Scott, J.

Abstract

The ongoing climate crisis provides a unique challenge within the residential sector to reduce greenhouse gas emissions by 2050 in response to Canada's net-zero goal. Although legislation has been put in place to address the decarbonisation of the existing housing stock, the challenging goal set by the Canadian government requires action beyond current energy guidelines. This poses a difficult challenge regarding the retrofit of housing built in the 19th and early 20th century. The extensive retrofit needed to bring these houses to the highest level of residential sustainability may counteract the idea of national zero-carbon when considering embodied carbon. This paper seeks to evaluate the whole-life carbon impacts of implementing deep retrofits in 19th and early 20th-century Canadian homes using the EnerPHit standard. To achieve this objective, the study compares whole-life carbon emissions under a non-retrofit baseline and a retrofit scenario that adheres to the EnerPHit standard, focusing on homes in Southern Ontario. HOT2000 Energy simulation software was used to assess the operational energy consumption, while One Click LCA was used to evaluate the whole life carbon of the two scenarios. This study found that the deep retrofit resulted in a 60% reduction in annual operational emissions compared to the baseline scenario. The whole-life carbon assessment further demonstrated a 48% reduction in total emissions over a 60-year period, with a carbon payback period of 6.8 years. These results imply that adapting this retrofit strategy would be beneficial to meeting Canada's 2050 net-zero goals, as the operational energy savings are superior to the total embodied carbon associated with the retrofit strategy.

Citation

MANCINI, A., SEDIKKI, M. and SCOTT, J. 2025. Assessing whole life carbon impacts of retrofitting Canada's 19th and early 20th century homes towards net-zero. In Kouider, T. and Galiano Garrigós, A. (eds.) Proceedings of the 11th International congress on architectural technology 2025 (ICAT 2025): buildings fit for climate change, 15-17 May 2025, Alicante, Spain. San Vicente del Raspeig: Universidad de Alicante [online], pages 355-369. Available from: http://hdl.handle.net/10045/154581

• Presentation Conference Type: Conference Paper (published)
• Conference Name: 11th International congress on architectural technology 2025 (ICAT 2025): buildings fit for climate change
• Start Date: May 15, 2025
• End Date: May 17, 2025
• Acceptance Date: Feb 14, 2025
• Online Publication Date: Jun 11, 2025
• Publication Date: May 31, 2025
• Deposit Date: Feb 14, 2025
• Publicly Available Date: Jun 16, 2025
• Publisher: Universidad de Alicante
• Peer Reviewed: Peer Reviewed
• Pages: 355-369
• ISBN: 9788413023182
• Keywords: Net-zero; Retrofitting; Older buildings; Retrofit; Whole life carbon; Canada
• Public URL: https://rgu-repository.worktribe.com/output/2702690
• Additional Information: The full proceedings of this conference is available from http://rua.ua.es/dspace/handle/10045/154489
• External URL: http://hdl.handle.net/10045/154581
• Other Repo URL: http://hdl.handle.net/10045/154581