NBC 2025 update

What changed in the NBC 2025 National Building Code of Canada?

The 2025 NBC introduces GHG emission limits for buildings, expands accessibility to all dwelling unit types, raises mass timber height allowances to 50 metres, adds a new Part for alterations to existing buildings, and updates climatic data to reflect projected future conditions.

The 2025 National Building Code of Canada is a significant update from the 2020 edition. It introduces Canada's first measurable operational GHG emission requirements, expands accessibility provisions to cover all dwelling units, updates structural load calculations for wind and snow, and adds an entirely new Part dealing with alterations to existing buildings. Provincial adoption timelines will vary, so confirming which edition applies to your project is the essential first step.

What to check first

  • First explicit operational GHG emission limits for buildings in the national code.
  • Accessibility provisions expanded to all dwelling unit types with adaptable unit requirements.
  • Mass timber construction height raised to 50 metres while retaining a 12-storey limit.
  • New Part for alterations to existing buildings covering energy performance upgrades.
  • Updated climatic data tables reflecting projected future temperatures and wind pressures.

Jurisdiction notes

National baseline

The NBC 2025 is a model code. It does not take effect until a province or territory formally adopts it.

Provincial adoption timing

Each province adopts the NBC on its own schedule. Confirm which edition applies before relying on any 2025-specific provision.

Transition projects

Projects submitted under the 2020 NBC may or may not be required to comply with 2025 provisions depending on local transition rules.

Work through it in this order

  1. Confirm which NBC edition your province has adopted or plans to adopt for your permit timeline.
  2. Identify which 2025 changes are relevant to your project type, occupancy, and construction method.
  3. Review the specific technical changes in the sections that govern your project.
  4. Cross-check provincial amendments that may modify or delay adoption of specific 2025 provisions.

Common questions

Is the NBC 2025 in effect now?

The NBC 2025 is published but only takes effect when a province or territory formally adopts it. Check your local adoption status.

Do I need to redesign my project for NBC 2025?

Only if your jurisdiction has adopted or will adopt the 2025 edition before your permit is issued. Projects already permitted under the 2020 NBC generally continue under that edition.

What is the biggest change in NBC 2025?

The introduction of operational GHG emission limits is the most significant new requirement, but the existing buildings Part and accessibility expansion also represent major shifts.