In 2022, on advice from the provinces and territories, the Canadian Commission on Building and Fire Codes (CCBFC) agreed to add an objective to the National Model Codes that relates to limiting greenhouse gas (GHG) emissions. This direction was adopted by the newly formed Canadian Board for Harmonized Construction Codes (CBHCC) in November 2022.

Proposed Part 11 of the NECB will contain the technical requirements for GHG emissions that apply to buildings. The application of Part 11 must be stated in Division A of the NECB.

Failure to state the application of these requirements may lead to a risk that the requirements will not be enforceable.

In order to meet provincial, territorial and federal GHG emissions reduction targets and climate action plans, including the goals to reduce Canada's total GHG emissions to 40–45% below the 2005 levels by 2030 and to reach net-zero GHG emissions by 2050, Code requirements are needed to mitigate the GHG emissions of new buildings.

In the 2020 edition of the NECB, energy efficiency tiers were introduced with measures that progressively increase energy efficiency in new buildings. While these requirements go a long way towards reducing the amount of energy used to operate a building, operational GHG emissions have not yet been addressed.

Excessive GHG emissions result in increased concentrations of GHGs in the atmosphere, which in turn can lead to climate change and a risk to the environment. Technical requirements for the design and construction of buildings that limit the excessive emissions of operational GHGs are needed to address climate change mitigation.

The impact analysis for proposed measures to limit GHG emissions will be provided in each of the respective proposed change forms that address the specific technical changes proposed for Division B of the NECB.

It is expected that new proposed changes to Code requirements that limit excessive emissions of operational GHGs will provide a benefit to society by mitigating the effect of climate change on the environment.

Enforcement of technical requirements to minimize excessive emissions of operational GHGs will require additional effort by the authorities having jurisdiction. Training material will be required to assist enforcement officials.

A consistent set of technical requirements to minimize the excessive emission of operational GHGs across Canada will contribute to meeting provincial, territorial and federal GHG emissions reduction targets and climate action plans, including the goals to reduce Canada's total GHG emissions to 40–45% below the 2005 levels by 2030 and to reach net-zero GHG emissions by 2050.

Designers, manufacturers, building officials, builders, building owners and specification writers.