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

If you are planning a project in 2024, follow this checklist:

Despite higher upfront costs, homeowners will see 20–30% heating/cooling cost reductions. The province also offers the Home Renovation Savings Program (2024) rebates up to $5,000 for achieving code-minimum energy performance. Despite higher upfront costs, homeowners will see 20–30%

One of the foundational aspects of the 2024 OBC is its alignment with the National Building Code of Canada (NBC). Historically, Ontario maintained distinct variations that created barriers for national designers and manufacturers operating in the province.

The 2024 edition adopts the National Research Council’s (NRC) objective-based format more thoroughly. This harmonization allows for: One of the foundational aspects of the 2024

However, the province has retained "Ontario-only" amendments where local context dictates, particularly regarding snow loads, seismic activity, and specific fire safety requirements for high-rise buildings.

Ontario has updated its climatic data. The "1-in-50-year snow load" and "wind pressure" maps have been rezoned.

The 2024 Code aligns Ontario closer to the National Energy Code. The biggest change here is airtightness.

To directly combat the housing shortage, the 2024 OBC includes regulatory relaxations for Additional Residential Units (ARUs), often referred to as laneway suites or garden suites.