Cutting emissions in the buildings sector through Canada’s national model codes

Kevin Lockhart

Kevin Lockhart

Efficiency Buildings Lead, Efficiency Canada

July 25, 2022

Blogs | Buildings | New Buildings | News

  • Supported by the sector, a new national model code objective has been put forward that recognizes the impact of operational and embodied carbon emissions throughout the buildings lifecycle.
  • This change could open the door for building code provisions that limit or reduce emissions from building operations as well as construction materials.
  • Doing so is crucial to market transformation signals to market, investments, jobs.

Canada’s first national standard for building energy performance was established in 1997. This was the Model National Energy Code for Buildings.

Since then, our building energy codes have placed greater emphasis on increasing the energy efficiency of the places we live, work and play. Most recently, this evolution led to the introduction of a tiered approach to reducing energy waste in Canadian buildings in the 2020 national model codes.

Until now, the model codes have exclusively considered the energy performance, rather than carbon performance, of new buildings. This means that even at the most stringent tiers, emissions from building operations cannot be tackled directly through our current building codes. These emissions are largely from space conditioning, hot water heating, or the carbon embodied in construction materials. This gap has been noted by advocates and sub-national governments alike.

Embodied carbon: The amount of carbon dioxide emissions and other global warming gasses needed to make construction materials. Embodied carbon includes the embodied energy used to extract, refine, process, transport and fabricate a building material.

This can be expected to change. As of early June 2022, a new objective to address excessive greenhouse gas emissions (GHG) from new buildings was proposed for the national model codes.

In this blog, we look at what addressing emissions via the national model codes means for Canada’s buildings sector.

The Model Codes objectives define its desired outcomes

In the early 2000s, Canada adopted an “objective-based” code system that ties the provisions (requirements) of the model code to five objectives. These include:

  1. Safety
  2. Health
  3. Accessibility for persons with disabilities
  4. Fire and structural protection of buildings
  5. Environment

Found within Division A of the model codes, these objectives provide information for code-users to achieve code compliance with both objectives, sub-objectives, and “policy” level information. These reflect Canadians’ expectations related to the design, construction and operation of buildings. The model codes’ requirements are considered the “minimum acceptable” measures required to achieve these five objectives.

Changes to these five objectives and their sub-objectives fall within the oversight of the Canadian Commission on Building and Fire Codes’ (CCBFC) Executive Committee. This committee reviews the merit of code change requests (CCRs), including those related to Division A of the model codes. 

A key objective of interest is the Environment objective. It sets out to “limit the probability that, as a result of the design or construction of the building, the environment will be affected in an unacceptable manner.”[i] 

An accompanying sub-objective, ‘Resources,’ is intended to limit the likelihood that resources used in the design or construction of the building will have an unacceptable environmental impact. Notably, this includes environmental impacts caused by excessive energy use, but not those arising from emissions related to building operations or materials used in a building’s construction.

However, a shift in this dynamic is underway. This past spring, the CCBFC cleared the path for the model codes to directly address emissions and thus better support Canada’s net zero by 2050 goals. The committee added a “Climate change mitigation” policy task for the 2020-2025 code cycle. And building on this measure, Natural Resources Canada and the National Research Council Canada recently submitted a Code Change Request (CCR) to add a new objective: OE2 Atmospheric Quality. This objective would also include the sub-objective OE2.1 excessive emission of greenhouse gasses: aimed at limiting the probability of unacceptable risk related to GHG emissions resulting from the design or construction of buildings.

Why it matters

Canada’s recently published national model codes offer a tiered framework that incrementally increases the energy performance of new buildings, leading towards the highest tier of net zero energy ready standards. Nonetheless, tiered code compliance does not assure reductions in either the GHG emissions generated from the building operations, nor the emissions generated throughout the manufacturing, transportation, and disposal of construction materials.

Adding emissions to the code’s objectives has long had the support of many in the buildings sector. Building on the energy efficiency measures incorporated into the model codes over the past decade, it clears a path for the development of technical requirements that limit or reduce GHG impacts of buildings. It can also be expected to contribute to the development of the 2025 model codes, Alterations to Existing Buildings Code, and of course the forthcoming Net Zero Emissions Code. 

Energy efficiency continues to be the cornerstone of any approach to increase the carbon performance of Canadian buildings. As highlighted previously, achieving significant emission reductions begins with minimizing the building’s energy demands, ensuring mechanical systems use zero-carbon fuels, and using low-carbon construction materials and building components.

These fundamental steps are key as there is a risk that some in the buildings sector might forgo energy efficient design changes and construction practices based on the faulty assumption that simply switching existing materials for low-carbon building materials captures the same outcomes.  However, energy efficiency is key to achieving deep emissions reductions while capturing the many co-benefits of energy efficiency.

Achieving net-zero emissions by 2050 in Canada means some sectors will need to achieve zero emissions and undertake further transitions to support GHG reductions elsewhere in the economy.

On a sector-wide basis, energy efficient buildings can help:

  • Free up clean energy resources for more productive uses
  • Reallocate clean electricity to capture emissions reductions in transportation and industry
  • Catalyze transformative changes in upstream industrial emissions
  • Contribute to a future negative emissions scenario


Canada’s national model codes have played a critical role in signaling to the buildings sector the priorities of both government and the public. They have evolved from an early emphasis on health and safety to more recently encompassing energy efficient construction.

Along the way, these changes helped developers, builders, all levels of government, and the workforce respond accordingly and invest in new areas of innovation.

Applying this same approach to the carbon performance of buildings via the addition of a new objective that recognizes the impact of GHG emissions is an important step in the market transformation of the buildings sector. Bolder building codes encourage long-term investments in low-carbon technologies, processes, and infrastructure to meet the demands of the buildings sector.


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