Upgrading buildings with deep retrofits is a “clear pathway” to meet Canada’s climate and affordability goals while increasing household resilience to extreme weather, finds new analysis from the Pembina Institute.

The institute shared [pdf] key findings from an initiative that challenged six design teams to collaborate on deep retrofit plans that would deliver energy efficiency and reduce carbon emissions, plus producing benefits beyond energy like climate adaptation, seismic resilience, improved occupant health and wellbeing, and reductions in embodied carbon.

Six low-rise buildings in British Columbia—one each in Vancouver, Victoria, North Vancouver, New Westminster, Coquitlam, and Kamloops—were selected for the design challenge. Each will see its respective “best-in-class” deep retrofit designs implemented between now and the end of 2025. And they all provide housing for vulnerable people—seniors, people with disabilities, and low-income households.

“Deep retrofits are holistic energy efficiency home upgrades that also improve occupant thermal comfort and resilience to extreme weather events, while making housing more affordable by stabilizing utility costs for customers,” Pembina wrote in a release. “This is achieved with the selection of low-carbon construction materials, installation of highly efficient technologies (like heat pumps), and integration with a supply of clean energy.”

“Improved insulation, modern heating and cooling systems, and better ventilation can generate better indoor air quality and protect occupants from cold snaps and extreme heat.”

The teams found “significant reductions” in energy consumed by space and water heating in all six deep retrofit designs. Energy savings ranged from 58% to 93% compared to baseline retrofits, which maxed out at 41% and went as low as 3% in one design that did not update windows. The reduction in energy use contributes to lower bills and greater affordability.

Deep retrofits of low-rise buildings can also make a dent in operational carbon emissions, the amount of carbon dioxide and other greenhouse gases emitted during the operation of a building, mainly from the combustion of fossil fuels for heating, cooling, and power generation. The teams estimated their deep retrofit designs will reduce operational carbon emissions between 68% and 99%, “a remarkable shift from the standard 3% to 55%.”

Such findings prove deep retrofits to be “clear pathways to drastically lower the carbon footprint of existing buildings,” writes Pembina. Critically, “all deep retrofit schematic designs are projected to reduce total energy use by at least 44% compared to existing building performance, despiteadditional energy use from adding ventilation and cooling to satisfy climate resilience and health and wellbeing objectives.”

The initiative also produced multiple proofs of the “non-energy benefits” of retrofits—better air circulation, more light, reduced noise—which all add up to healthier living spaces.

The challenge showed “how retrofitting buildings ensures occupant resilience to withstand climate change impacts, enhancing longevity and safety,” Pembina adds—measures that will protect tenants from, say, extreme heat, as B.C.’s summers are predicted to grow increasingly hot and dry.

The initiative found that embodied carbon from the proposed deep retrofit designs ranged from 25 to 125 kilograms of carbon dioxide equivalent per square metre (kgCO2e/m2), with an average of around 60 kgCO2e/m2—roughly four times lessthan an equivalent new low-rise building.

To promote and enable deep retrofits, Pembina calls on governments to introduce standards and regulations to “send a strong market signal,” and invest to help “build supply and demand for deep retrofits until the market reaches the economies of scale that lead to cost compression and a self-supporting business case for deep retrofits.” Governments must also educate homeowners and developers on “the value of holistic, long-term asset management plans that recognize key opportunities in component life cycles,” and invest in workforce development, the report says.