Heating, cooling and hot water in BC's energy-efficient homes: heat pumps, the 26°C cooling rule and gas limits

What the code asks of heating

Article 9.33.2.1 requires homes used through the winter to have heating facilities. Sentence 9.33.3.1.(1) sets what they must do: at the outside winter design temperature, hold at least 22°C in all living spaces, 18°C in unfinished basements, and 15°C in heated crawl spaces. Table C-2 of the code sets the winter design temperature for each place; Vancouver City Hall is -7°C on the 2.5 percent January value.

Article 9.33.5.1 requires the capacity of heating and cooling appliances in a home to be found with CSA F280, the Canadian standard for sizing residential heating and cooling equipment, using the code's design temperatures. In a tight, well-insulated house the heat loss is small, so the sizing calculation matters: equipment sized by habit for an older house will be larger than the new house needs.

Article 9.36.3.10 requires heating, ventilation and air-conditioning equipment to meet the performance levels in Table 9.36.3.10. That table sets minimum efficiencies for equipment such as heat pumps and furnaces when they are installed. It does not tell you which kind to install.

Heat pumps in the code

A heat pump moves heat from outside air, the ground or water into the house in winter, and can run in reverse to cool in summer. The BC Building Code mentions heat pumps in a few places, and none of them requires one. Sentence 9.36.2.6.(1) uses Table 9.36.2.6.-C where the home has a heat pump or a heat recovery ventilator. Sentence 9.36.6.5.(3) sets how the reference house is modelled when the design is heated by a heat pump.

The Zero Carbon Step Code is where fuel choice comes in. Table 9.37.1.3 gives each emission level three routes. Two are caps on emissions in kilograms of carbon dioxide equivalent, which any fuel can meet if the numbers work. The third requires energy sources at or below 0.011 kg per kWh for named systems, and Sentence 9.37.1.3.(2) gives electricity that factor and natural gas 0.180. On that route only electric equipment qualifies.

This agrees with our Journal post on the subject, published 14 October 2026: the code sets targets and the equipment follows from how you meet them. Nothing in the code has changed since. What changes the answer for a given lot is the city. At EL-4 in Burnaby the emission caps are 265 kg a year per house, or 1.5 kg per square metre with a 500 kg total. At the code's gas factor of 0.180 kg per kWh, 265 kg equals 1,472 kWh of gas in a year, for heating, hot water and every other counted use combined.

The cooling rule

Sentence 9.33.2.1.(2) requires homes used through the summer to have cooling facilities, unless a calculation under Article 9.33.5.1 or good engineering practice under Article 6.2.1.1 shows they are not needed. Sentence 9.33.3.1.(2) sets the target: at the outside summer design temperature, the cooling must hold the indoor air at or below 26°C in at least one living space in each home.

The province lists this as a B.C. change effective March 2024, and the BC Building Code 2024 applies to permits applied for after 8 March 2024. The province's extreme heat page says the rule followed the BC Coroners Service report on deaths in the 2021 heat dome, which recommended cooling requirements for new homes. It names a mechanical cooling system as a common solution. Note A-9.33.2.1.(2) adds that passive cooling designs can help reduce cooling loads.

For a single cooled room, the province hosts a Guideline on Single Zone Cooling in Dwelling Units, dated 14 March 2025, written by HVAC Designers of Canada and the Thermal Environmental Comfort Association. It is a voluntary good practice guide. It uses a 24°C design temperature for the cooled zone, counts occupants as the number of bedrooms plus one, and suggests at least 4.5 square metres of zone per occupant.

In a multiplex, the rule applies to each dwelling unit. A heat pump that heats and cools covers both rules with one system.

Hot water, cooking and where gas still fits

Hot water counts. Table 9.37.1.3 lists heating systems at EL-2, heating and service water heating systems at EL-3, and all building systems including equipment and appliances at EL-4 on its fuel route. The emission caps on the other routes count the energy for space heating, cooling, fans, hot water, pumps and other heating and ventilation equipment, as defined in Sentence 9.36.6.2.(1).

Back-up equipment gets an exception. Note (1) to Table 9.37.1.3 lets redundant or back-up equipment be left out of the count if it has controls and is not needed to meet the home's heating load. Richmond's page shows how a city applies this: under its Step 5 with EL-2 option, natural gas space heating may be modelled as a back-up system.

Cooking and fireplaces depend on the path. The province's Zero Carbon page says the prescriptive path asks builders to use lower-carbon equipment for space heating, water heating and cooking, while on the performance path energy advisors can show whether a gas fireplace, cooktop or dryer still fits. Burnaby's page says gas cooktops are allowed at EL-3 but not at EL-4 on the prescriptive path, and that the performance model, as of January 2024, did not rule out gas fireplaces or cooktops.

Moving heat and hot water to electricity adds load to the electrical service. On an older lot in Vancouver or Burnaby, check the existing service with the utility during design. The Journal post on the heat pump question covers that step.