Single Zone Cooling Guidelines in Dwelling Units
Information Bulletins
Cooling of a Single Living Space in Dwelling Units for Part 9 Residential
The Government of British Columbia
Construction Standards & Digital Solutions Branch
This bulletin provides information regarding the recently released guidelines for determining cooling loads for a single living space titled, "Guideline on Single Zone Cooling in Dwelling Units". These guidelines help to provide a methodology to appropriately size cooling systems in relation to BC Building Code requirements to minimize health risks associated with overheating of dwelling units.
Single Zone Cooling Guideline in Dwelling Units
HVAC Designers of Canada & TECA
Version 1.0a March 14, 2025
The BC Building Code (BCBC)-2024 introduced a maximum design temperature limit of 26°C for a minimum of a single living space in each dwelling unit. In April 2024, the Province of BC’s Building’s Safety and Standards Branch (BSSB) released Information Bulletin No. B24-08 that provides information on the new provisions in the BCBC 2024 related to minimizing the risks to health and safety due to overheating in dwelling units. Although the BSSB bulletin provided general information on requirements, and strategies with mechanical cooling systems as well as some passive design measures, it did not provide the necessary depth on the technical considerations to meet the BCBC 2024 requirements.
To address these concerns, HVAC Designers of Canada (HVAC DC) and the Thermal Environmental Comfort Association (TECA) together with stakeholders from the home building sector have developed a Guideline on Single Zone Cooling in Dwelling Units.
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