The combustion of fossil fuels (mostly natural gas and some oil) for space and water heating is the biggest contributor of GHG emissions in buildings. A net-zero building sector requires a shift away from fossil fuel heating systems across all commercial, institutional, and residential buildings.
Electrifying buildings is the most straightforward path to bring the sector to net zero. Millions of buildings are already heated by electricity in Canada, primarily with electric resistance furnaces or baseboard heaters. Newer technologies such as low temperature air source heat pumps and ground source heat pumps can dramatically improve efficiency, saving money for occupants. Over time, renewable natural gas (RNG) and/or hydrogen may provide a way to repurpose building heating infrastructure, which may be particularly useful in colder regions of the country.
Energy efficiency gains (higher quality building envelopes, heat recovery, better control systems, etc.) are important for new builds, but also for the millions of existing structures which will require retrofit.
Fully decarbonizing the building sector also requires replacing climate-warming refrigerants like HFCs and eliminating emissions from construction and building materials like steel, concrete, and aluminum.