Ontario Building Code 2024
While Ontario maintains autonomy, OBC 2024 aligns approximately 85% with NBC 2020. Key deviations remain:
| Aspect | Ontario 2024 | NBC 2020 | |--------|--------------|----------| | Wood-frame height | 6 storeys | 12 storeys (mass timber) | | Energy efficiency | SB-12 tiered | NECB 2017 | | Radon protection | Mandatory in all new homes | Mandatory in high-risk zones only | | Barrier-free thresholds | 13 mm max | 10 mm max |
Ontario retains stricter radon requirements and less aggressive mass timber provisions due to insurance and industry readiness concerns. ontario building code 2024
In response to catastrophic flooding in Toronto, Ottawa, and Windsor, the 2024 Code introduces mandatory flood-proofing measures.
If you are planning a project in 2024, follow this checklist: The Ontario Building Code (OBC) is the regulatory
The Ontario Building Code (OBC) is the regulatory bible for construction in Canada’s most populous province. It dictates how buildings are designed, constructed, renovated, and demolished. As of 2024, Ontario is undergoing a significant regulatory shift, moving toward a more harmonized system with the National Building Code while also introducing stringent energy efficiency and accessibility requirements.
For builders, architects, engineers, developers, and homeowners undertaking a major renovation, understanding the Ontario Building Code 2024 is not just a legal obligation—it is the cornerstone of a safe, durable, and lawful project. The Supplementary Standard SB-12 has been overhauled
Note: The OBC is typically amended every 5 years. While the “2024” designation reflects the latest amendments and supplementary requirements (often referenced as OBC 2024 or the 2024 edition of Supplementary Standards), the base code remains Ontario Regulation 332/12, as amended. This article reflects the most recent changes effective throughout 2024.
The Supplementary Standard SB-12 has been overhauled. For residential homes (Part 9 buildings), prescriptive thermal resistance (R-value) requirements have increased:
The Game Changer: Airtightness Testing New Part 9 residential construction must now undergo blower door testing, achieving ≤ 2.5 Air Changes per Hour (ACH) at 50 Pascals. This is a major step toward Passive House standards.