A new era for building codes in Canada

Canada’s newly released 2025 National Model Codes mark a turning point in how the country looks at building performance. For the first time, the codes introduce explicit, measurable requirements to limit operational greenhouse gas (GHG) emissions, alongside new compliance pathways and updated climatic data that reflect the realities of a changing climate.  

For municipalities, academics, energy consultants, and developers, this update is more than a technical revision — it’s a policy signal. The federal government is acknowledging what cities have been acting on for years: GHG emissions are a building code issue, and codes must evolve to support climate‑aligned development. 

A clear step forward: What’s new in the 2025 codes

The Canadian Board for Harmonized Construction Codes (CBHCC) outlines several significant changes that reshape expectations for new construction: 

1. Operational GHG limits become a formal requirement

Both the National Building Code (NBC) and the National Energy Code for Buildings (NECB) now include performance and prescriptive requirements to limit operational GHG emissions. This is the first time GHG emissions have been embedded directly into the national model codes, moving climate considerations from the margins into the core of regulatory practice. 

The codes also incorporate updated climatic data that reflect projected future conditions. This shift acknowledges that buildings must be designed for the climate they will operate in — not from decades past. 

2. An optional Energy Use Intensity (EUI) pathway

The codes introduce an EUI‑based compliance path for several building types like offices, schools, multi-family buildings, housing, and small buildings (NECB and NBC). This gives designers and developers a flexible, performance‑driven option that aligns with how many municipalities already structure their Green Development Standards (GDS). 

3. Prescriptive compliance for energy performance tiers

The national codes maintain the tiered performance framework — four tiers for large buildings and five tiers for small buildings. This structure creates a built‑in roadmap for progressively higher performance and offers a ready‑made mechanism for provinces to enable local leadership while maintaining consistency.  

The codes also now include prescriptive options for Energy Performance Tiers 1 and 5, providing clearer, more predictable pathways for compliance. This is particularly important for industry, which has long asked for harmonized, transparent requirements across jurisdictions. 

4. Inclusion of existing buildings 

While optional for adoption, the new Part 10 introduces a framework for alterations to existing buildings. This signals a broader move toward lifecycle‑based regulation, something municipalities have been advocating for as they work to decarbonize their building stock. 

Why this matters for cities 

Municipalities across Canada and the GTHA have been advancing Green Development Standards (GDS) for years. These local standards include GHG performance metrics and design requirements that don’t exist in most provincial codes. Some cities like Vancouver and Toronto have also developed or begun developing standards for existing buildings.  

The national update validates this municipal leadership. By embedding GHG emissions directly into the model codes, the federal government is effectively acknowledging that: 

• GHG emissions are a building performance issue 
• Codes and standards must address climate impacts 
• Municipal innovation has been directionally correct 

This alignment strengthens the policy foundation for cities that have been pushing the envelope on modern development.  

The tiered structure of the national codes is especially important for municipalities.  

If Ontario were to adopt multiple tiers, they could then allow municipalities to select the tier that best fits their local context. This would create a consistent provincial framework while preserving municipal ambition. The BC Energy Step Code has already demonstrated that this model works: the province sets the tiers, and municipalities choose the level that aligns with their climate goals and market readiness. The 2025 national codes make it straightforward for Ontario to adopt a similar approach.  

Federal–municipal alignment: A signal to industry 

Developers have long called for harmonization across jurisdictions. Fragmented requirements—federal model codes, provincial codes, and municipal GDS—should be coordinated and complimentary.  

The 2025 model codes send a clear message that Canada is moving toward a unified, modern regulatory framework for buildings. 

Federal and municipal priorities are now visibly aligned on: 

• Reducing operational GHG emissions 
• Providing EUI and GHGi based compliance options 
• Supporting electrification and low‑carbon design 
• Offering tiered performance levels

This alignment reduces risk for developers and consultants, who can now plan for a future where GHG performance is a standard part of code compliance. 

Provincial participation 

While the national model codes set the direction, provinces control adoption—and this is where the gap remains. Some provinces have been slow to update their building codes or have resisted integrating GHG metrics. Ontario has long exempted itself from energy and GHG (and many other) aspects of the national code, and has also introduced legislation that may limit municipal green standards.  

For developers working across multiple jurisdictions, this inconsistency is a barrier to investment and long‑term planning. It also saddles building owners and residents with poorer assets that are more expensive to operate.  

Adopting the national tier framework would give provinces a practical path forward. By enabling municipalities to select from provincially adopted tiers, provinces could support both harmonization and local leadership. This approach would reduce regulatory conflict, provide industry with clarity, and align Ontario with a model already proven in B.C. 

If provinces want to support industry certainty, climate goals, and economic competitiveness, they need to move in step with the federal direction and the leadership shown by cities. 

A step toward true harmonization 

The 2025 National Model Codes represent a major step toward a unified, modern building regulatory system. They embed GHG performance into the heart of code compliance, offer flexible pathways like EUI, and provide prescriptive clarity that industry has long requested. 

But harmonization — a top priority for developers — will only be achieved if provinces adopt and implement these changes into their building codes in a timely and consistent way.