Preparing buildings for extreme heat

Extreme heat events happen when daytime and nighttime temperatures get hotter each day and are above seasonal norms. Preparing buildings for extreme heat helps protect people’s well-being and strengthens community health.  

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BC Building Code cooling requirements 

The B.C. Coroners Service released a report about the 2021 heat dome Extreme Heat and Human Mortality: A Review of Heat-Related Deaths in BC (PDF, 1.2 MB). The report recommended cooling requirements for the BC Building Code for new housing construction and existing home renovations.  

In response, the 2024 BC Building Code requires all newly constructed homes to have a living space that is designed to prevent indoor temperatures from rising too high. A common solution is to install a mechanical cooling system to maintain a manageable indoor temperature. 

• Guideline on Single Zone Cooling in Dwelling Units (PDF, 859 KB) provides information to support users in complying with the new BC Building Code maximum design temperature  

Preparing buildings for extreme heat is important  

Extreme heat impacts buildings differently. When there is extreme heat outside, it can lead to dangerously high indoor temperatures, posing severe health risks. In B.C., extreme heat events have caused hundreds of heat-related deaths. As events like heat domes are expected to become more common, preparing buildings for these conditions is important.  

There is no single way to prevent buildings from overheating. Effective temperate regulation depends on:

• Building type
• Location
• Resources 

Some strategies include:

• Vegetation for natural shade 
• Heat pumps for efficient climate control 

Resources for designers and builders 

• BC Housing’s 2019 Design Guide Supplement S3 on Overheating and Air Quality provides ways to address overheating and indoor air quality including vegetation for shade and heat recovery ventilators 
• ASHRAE 100 is an international building standard for improving energy efficiency in existing buildings. It was developed by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE). The ASHRAE 100 User’s Guide (PDF, 7.2 MB) provides more details about Standard 100 and improving energy efficiency
• Climate resilience buildings: guideline for management of overheating risk in residential buildings was developed by National Research Council Canada and provides information to manage risks to overheating in residential buildings 
• The Climate-resilient buildings and core public infrastructure 2020 report assesses how climatic design data for buildings and bridges may change as the climate gets warmer 

Financial support for individuals to upgrade homes 

Energy efficiency upgrades not only reduce energy consumption costs but they also help reduce overheating.

• The CleanBC Better Homes BC program helps British Columbians find rebates for some upgrades (such as, insulation, windows, doors and more) that save energy and lower greenhouse gas emissions. There are rebates for existing buildings and rebates for building new homes
• The Canada Greener Homes Loan can help Canadians make their homes more energy efficient and comfortable. The program uses financing and grants to help with some retrofits that may be recommended by an energy advisor

Financial support for organizations and communities to build or upgrade buildings 

• The CleanBC Better Buildings BC program provides funding and capital incentives to encourage energy efficient design, construction and renovation of commercial buildings 
• BC Housing’s Mobilizing Building Adaptation and Resilience is an ongoing project to help people protect their homes or buildings from the impacts of climate change 
• The Union of BC Municipalities has a Community Emergency Preparedness Fund available to help  local governments, First Nations and communities when responding to emergencies