Made-in-Canada Construction Can Cut Emissions at No Extra Cost

Canada needs five million affordable homes by 2030—and building them with Canadian-made low-carbon materials, paired with smarter design, could slash emissions at “negligible” cost while supporting local industries, says Clean Energy Canada (CEC).

Clean construction products and practices offer a “single elegant solution” to the complex challenge of building millions of affordable housing units during a climate crisis—and at a time when the United States can no longer be relied on as a trade partner, CEC says in a new report, Building Toward Low Cost and Carbon.

Without a shift in how buildings are designed and built, meeting Canada’s housing targets will generate nearly 730 million tonnes of additional emissions by 2030—more than the country’s total emissions for an entire year.

Address Embodied Carbon

Those emissions come from the materials and processes used in construction—the “embodied carbon” that includes emissions from production, transportation, assembly, maintenance, and end-of-life disposal. These often take a backseat to “operational” emissions like heating, cooling, and electricity use.

But as buildings become increasingly electrified and energy-efficient, embodied carbon will make up a larger share of their emissions impact, writes CEC, citing research by the Canada Green Building Council. CAGBC finds that by 2050, the “embodied emissions of an efficient electrically heated building can make up as much as 93% of the building’s cumulative emissions impact.”

Canadian-Made, Low-Carbon, Low-Cost

Fortunately, Canada is well-positioned on materials, Clean Energy Canada says. Structural steel, concrete, rebar, drywall, and insulation produced domestically are already lower in carbon intensity than many imported alternatives—with manufacturers seeing a “built-in advantage” thanks to the country’s relatively clean electricity grid.

• Canadian steel is already 16 to 200% less carbon-intensive than its American, European, or Chinese counterparts. The ongoing shift away from blast furnaces to electric arc will further slash structural steel emissions, with an estimated 10 to 100% reduction expected for new buildings.

• Canadian concrete production offers another slice of “good news” with less carbon-intensive inputs, cleaner kiln fuels, and onsite carbon capture contributing to as much as 32% lower emissions in a notoriously carbon-intensive building material.

• For rebar—the heavy iron rods that enhance tensile strength in concrete—a combination of domestic recycling and an expected shift to less carbon-intensive smelting processes could reduce embodied carbon by as much as 53%.

• Canada is also looking good on reducing gypsum drywall emissions, with a new wallboard plant set to open outside Montreal this year with a target of 60% lower emissions than the standard.  “Production of low-carbon gypsum wallboard is also slated to start in Alberta, providing more options in local markets,” CEC adds.

• Canadian innovations in low-emissions insulation are another bright spot. CEC cites Soprema, a French multinational operating in Quebec, and its creation of a rigid insulation panel with 98.7% lower emissions than the industry average.

The cost difference for all this innovation is minimal. “Cutting carbon won’t break the bank,” CEC writes. Where price premiums do exist, they’re typically small enough to be “rounding errors”—minor fluctuations in the overall cost of billion-dollar construction projects.

“Put simply, cutting carbon won’t break the bank,” CEC writes.

Design Makes a Difference

Even bigger emission reductions can come earlier in the process with design decisions that reduce the overall use of materials, the report adds.

For instance, high-rise buildings in Canada typically use the “same reinforcement and concrete designs” for all stories, despite higher stories carrying far less weight than the ones below. “If each storey was designed optimally, a 15- to 20-floor building could save as much as 45% of the column, beam, and wall concrete.” Optimally designed buildings would also avoid concrete-intensive underground amenities like basements and parking garages.

Climate resilience measures like pitched roofs rather than flat ones, and envelope simplifications like reimagining wind-exposed balconies, are other options.

Carbon-conscious design “can reduce embodied emissions by as much as 41% while saving hundreds of thousands of dollars in material costs,” CEC writes.

Policy Matters

Federal “Buy Clean” commitments and efforts under the Canada Green Building Strategy are already helping to drive change, CEC says. Cities like Vancouver, Toronto, and Hamilton are also advancing embodied carbon policies that require reporting and reduction.

Up next should be the “re-evaluation of building codes and design guidelines to remove unnecessary restrictions on lower-carbon designs while focussing on carbon performance over prescriptive requirements,” the report says. Governments will also want to support smaller producers in their efforts to gather emissions-related data for potential customers.

“With government support, Canada’s green building sector is expected to grow more than threefold by 2030,” writes CEC.  The sector will generate “hundreds of thousands of new jobs and billions of dollars in economic benefits,”  while boosting trade relations with “like-minded” partners like the European Union.

This story is part of The 89 Percent Project, an initiative of the global journalism collaboration Covering Climate Now.