To keep up with rising demand for housing and infrastructure, Canada will need approximately 5.8 million new houses by 2030, representing a staggering 40% increase. Building designers face increasing pressure to restrict the GHG emissions associated with their construction projects as federal commitments to emissions reductions accelerate. One way to standardize the reduction of embodied carbon associated with new developments is through policies such as Toronto’s Green Standard (TGS); a framework guiding the development of resilient and decarbonized buildings for the major Canadian metropolis.
In Canada, the TGS represents both a model and proactive approach to reaching Toronto’s mission of net zero by 2040 through strict requirements for new buildings related to materials, water use and energy. Currently, the TGS is enabling the reduction of an outstanding 15,000 tons of CO2e per year.
The Toronto Green Standard was first introduced in 2006, and has since evolved through four versions, the most recent having been launched in 2022. Impacting both new city-owned and private developments, the TGS operates as a tier system in which tier 1 performance measures are mandatory while tiers 2 to 4 are higher level voluntary standards. Building designers can seek financial incentives through pursuing TGS approval under the “Development Charge Refund Program” which provides increasing rebate rates for each tier of the TGS that is met beyond tier 1.
One of the primary paths to reaching tiers 2-4 lies in limiting a building’s embodied carbon emissions. In TGS v4, upfront embodied carbon intensity must remain below 350 kg CO2e per m2 for “Mid to High-Rise Residential & Non-Residential Buildings”, which is mandated for new city-owned buildings, and optional for private-owned buildings hoping to reach tier 2 of the standard. “Low-Rise Residential Buildings” must meet a stricter limit of 250 kg CO2e per m2 to reach the same tier 2 level. In both cases, an assessment of emissions from building materials must be conducted, and low-carbon material alternatives must be considered.
The Canadian Green Building Council considers highly-consumed building materials, such as concrete and steel, as principal drivers of a building’s overall embodied carbon—making them essential starting points for embodied carbon reduction. Building design and construction professionals are thus looking to sustainable solutions—like CarbiCrete-enabled concrete—to make meeting TGS and other green building certification requirements an easier task.
CarbiCrete technology allows concrete manufacturers to produce 100% cement-free concrete masonry products. Through this replacement of cement—which is responsible for 88% of conventional concrete’s embodied carbon—CarbiCrete-enabled products significantly contribute to reducing a project’s embodied carbon and meeting green building certifications, such as the TGS. CarbiCrete technology also removes historic emissions during curing, resulting in the most complete solution to a notoriously emissions-intensive industry.
Toronto’s continued commitment to mandating green building represents a replicable model for Canada’s major metropolises to decarbonize their building activities and contribute to net zero via construction. Updates to the TGS are expected to be active in 2025, bringing with them both optimism and stricter regulation for a greener built environment.
