Aggressive policy at all levels of government can help Canada avoid 100 megatonnes of carbon emissions per year while building the 5.8 million new units that will be needed to solve the housing crisis, concludes an analysis released this week by the Task Force for Housing & Climate.
“How and where” these new homes are built carries major implications for Canada’s climate goals, writes the task force co-chaired by former Conservative cabinet minister Lisa Raitt and former Edmonton mayor Don Iveson.
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To figure out how best to add millions of new homes—nearly one-third of Canada’s existing housing stock—with the least climate harm, the task force commissioned three reports to explore greenhouse gas (GHG) emissions associated with building energy performance, embodied emissions from construction materials, and land use planning. They collectively show that “with weak policy approaches, adding 5.8 million homes could lock in as much as 142.7 Mt in new annual GHG emissions in 2030,” the task force writes. On the other hand, with aggressive policy approaches, adding the same number of units could generate “as little as 43 Mt of annual GHG emissions in 2030.”
“In other words, strong policy leadership at the federal, provincial and municipal levels could prevent almost 100 Mt of annual GHGs from new housing—or 34% percent of Canada’s 2030 GHG reduction target under the Paris Agreement.”
To achieve the 43-Mt target, policy-makers will need to ensure top-flight building energy performance, lowest possible embodied carbon, and land use planning decisions that prioritize density.
One report produced by Efficiency Canada and Carleton University urges [pdf] policy-makers to mandate that:
• All provinces move to Tier 3 of the National Building Code and Tier 2 of the National Energy Code for Buildings in 2025, and then rapidly progress toward the upper tiers’ net-zero energy ready standard in 2030.;
2) All new buildings are electrified by 2025.
In contrast, sticking with business-as-usual building standards, with limited provincial implementation of the National Building Code and no electrification mandates, would lead to a 12.9-Mt increase in annual GHG emissions in 2030. Illustrating the need to get serious about electrification, Efficiency Canada found that rigorous application of building codes, with no mandate to electrify by 2025, would still raise annual emissions by 10.4 Mt per year by the end of this decade.
Aligning Canada’s housing and climate imperatives also requires attention to the embodied GHG emissions associated with construction and supporting infrastructure, like roads.
Modelling by the Centre for the Sustainable Built Environment, which producedthe second report, shows [pdf] that under a worst-case scenario where “all new housing is single-family detached homes built in greenfield areas using current GHG-intensive construction methods,” 94.2 Mt of annual GHG emissions are generated in 2030.
But if all new housing is built in multi-unit buildings within existing urban boundaries, and is efficiently designed while minimizing the demolition of older buildings, Canada will see a whopping payoff in emissions reductions. Under this scenario, annual emissions from embodied carbon fall to only 8.0 Mt in 2030—a savings of 86.2 Mt per year.
Tackling the third and final piece of the puzzle, land use planning, the Smart Prosperity Institute found that building homes as infill in urban areas and, ideally, close to transit will limit land use-related emissions increases to 30.8 Mt, a saving of 4.8 Mt per year compared to business-as-usual planning.
