Ontario Building Code - 2024

The 2024 code integrates more stringent Accessibility for Ontarians with Disabilities Act (AODA) requirements into the core building code. Key changes include:

A common question: "I have a permit approved under the old code. Am I forced to follow the 2024 rules?"

Critical Alert: If your permit lapses or you request a major revision after 2024, the building official can require full compliance with the new code.

OBC 2024 retains the 9-division structure but introduces significant reorganization: ontario building code 2024

The code adopts numbering and many clauses from the National Building Code of Canada 2020 (NBC 2020) but modifies them for Ontario-specific climate, construction practices, and economic priorities.

| Milestone | Date | |-----------|------| | Code filed under Ontario Regulation 391/24 | October 2024 | | Official release and publication | December 2024 | | Voluntary early adoption | January 1, 2025 | | Mandatory compliance | July 1, 2025 (for most buildings) |

Exception: Larger, more complex buildings (e.g., Part 3 major occupancies) have a delayed mandatory date of January 1, 2026 to allow design and engineering transitions. The 2024 code integrates more stringent Accessibility for

| Component | 2019 Code Cost | 2024 Code Cost | Delta | | :--- | :--- | :--- | :--- | | Wall insulation (R-22 cont.) | $3.50/sq.ft | $6.00/sq.ft | +71% | | Windows (triple-pane req.) | $500 each | $800 each | +60% | | Blower door test | Not required | $500–$1,000 | New | | Sprinklers (per townhouse) | $2,500 | $5,000 (mandatory) | +100% |

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 | Critical Alert: If your permit lapses or you

Ontario retains stricter radon requirements and less aggressive mass timber provisions due to insurance and industry readiness concerns.

In response to catastrophic flooding in Toronto, Ottawa, and Windsor, the 2024 Code introduces mandatory flood-proofing measures.