Highlights from the 2025 National Building Code for Alberta builders
The 2025 National Model Codes, published in December 2025, represent changes in Canada’s approach to building performance. For the residential construction sector, specifically housing and small buildings, Section 9.36 of the National Building Code is the focal point of these updates. The new code introduces explicit requirements for greenhouse gas (GHG) emissions, new compliance pathways, and upgraded energy-efficiency standards.
This blog outlines the major changes in Part 9 building construction that the industry should prepare for.
1. The roadmap to net zero: Energy performance tiers
The 2025 National Building Code maintains and expands the tiered performance framework from the previous version, outlining a path toward higher energy efficiency. For small buildings and housing, there are five energy performance tiers. Tier 1 represents the minimum code requirement, and Tier 5 represents net-zero energy-ready performance.Â
There is now greater flexibility in how to achieve these tiers. The compliance paths include:
- The Energy Use Intensity (EUI) method: A new performance path that allows builders to compare their home’s annual energy consumption against a target EUI based on the building’s type.
- Revised points-based trade-off: The points system has been updated so builders can exceed requirements in one area to compensate for falling short in another. Points are awarded for upgrades such as drain-water heat recovery, air-source heat pumps, and improved airtightness.Â
- Prescriptive paths for Tiers 1 and 5: Clear checklists are now available. Tier 1 now requires an Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV). Tier 5 requires airtightness testing, improved assembly U-values, a heat pump for principal heating, a heat pump water heater, and drain-water heat recovery.Â
2. Operational GHG emissions: The "Alberta challenge."
For the first time, the National Building Code introduces a measurable requirement to limit operational greenhouse gas emissions. Homes are ranked from Level A, the highest performance level, to Level F, the minimum compliance level.Â
This presents challenges for Alberta. The carbon intensity of the provincial electricity grid heavily influences performance levels. Because Alberta operates on a high-carbon-intensity grid, with a projected grid emission factor of about 182, homes built here may require additional measures to meet targets than those in provinces with cleaner grids, such as British Columbia or Manitoba.
Key considerations include:
- The gas penalty: Under the prescriptive path, homes using utility gas for space and water heating likely fall into Level E or F. To reach Level C, utility gas cannot be used for space heating.
- Electric heat pumps: Even when switching to all-electric heat pumps, Alberta’s grid emissions factor limits the prescriptive pathways. Achieving Level A may be difficult under current assumptions without specific exemptions, such as claiming zero-emission solar PV sources. These are largely excluded from the standard calculations and would need provincial review before adoption. Achieving Level B with a heat pump with electric backup requires 65 energy conservation points.
3. Solar heat gains and mandatory airtightness
The 2025 code introduces a hard limit on the Solar Heat Gain Coefficient (SHGC) for windows, doors and skylights. This is intended to reduce the risk of overheating in highly efficient homes.
The maximum allowable SHGC depends on the climate zone and the ratio of glass to wall area. Alberta benefits from more flexibility because colder climate zones allow for a higher SHGC, recognizing the value of passive solar heating in winter.Â
Airtightness is also becoming a central focus. Testing is mandatory for Tiers 4 and 5, and builders are encouraged to begin blower-door testing for all homes. High airtightness provides one of the most cost-effective ways to accumulate energy conservation points and is often the most impactful upgrade for meeting the new code.Â
4. Alterations to existing buildings (Part 10)
Municipalities and renovators should be aware of the new Part 10: Alteration of Existing Buildings. While optional for provinces to adopt, it signals a broader move toward lifecycle-based regulation for existing buildings.
If adopted, Part 10 would require major component replacements in existing homes, such as HVAC systems, service water heating, or building envelope elements like windows and doors, to meet the energy-efficiency requirements of Part 9.36 for new construction. Basic maintenance and repairs are exempt, but full replacements can no longer be like-for-like if the old system did not meet modern energy standards.Â
Considerations for Alberta
Although the 2025 National Building Code has been published, provinces generally have an 18-month window to review and adopt the codes. This places potential implementation in Alberta around mid 2027.Â
With this timeline, it is important for the industry to understand how current designs align with the new 9.36 tier and GHG emission frameworks. Knowing where your current builds stand in relation to the new EUI metrics, the points-based trade-offs, and Alberta’s grid emission factors can inform planning for the costs and design requirements when the province harmonizes with the new regulations. Stay tuned for compliance tools from NRCAN and resources in the ENBIX library.
