Ontario Building Code Updates
The 2024 Ontario Building Code (OBC) came into effect on January 1, 2025 – the largest ever change in the OBC with +1,700 items being revised. The HCRA continues to supporting your educational needs as you prepare to adapt to these new requirements.
Licensees are encouraged to bookmark this page, to access up-to-date information on the 2024 OBC.
Through the links below, you can sign up for Building Code updates through CodeNews, request a copy of the latest Building Code Compendium, and watch the webinars offered by Ministry of Municipal Affairs & Housing (MMAH) which can be accessed by dropbox after filling out the form.
What you Need to Know about the Transition Timelines:
- April 10, 2024: Release and filing of the 2024 Ontario Building Code.
- January 1, 2025: 2024 Ontario Building Code in effect.
- March 31, 2025: Deadline for permit applications using the 2012 Ontario Building Code, where working drawings were substantially complete before January 1, 2025.
- April 1, 2025: All permit applications must use the 2024 Ontario Building Code.
Key Areas of Focus for the Ontario Building Code:
New houses in Ontario will require a rough-in for a subfloor depressurization system to address soil gas/radon. View our radon resources for builders here.
Updates, found in article 3.1.6.3, allow new occupancies to use mass timber and specify the range of heights (up to 18 stories) for fully exposed timber, except in exits and public corridors. Click here for the guide to encapsulated mass timber projects.
Ontario has aligned with the National Building Code (NBC) for secondary suites but will maintain flexibility on suite sizes to support housing objectives and minimize costs. Information on requirements such as ceiling heights, fire separation, and shared air systems can be found on the following page from Suite Additions: The New 2024 Ontario Building Code: What You Need to Know for Second Suites & Multiplex Conversions
The Heat, Refrigeration and Air Conditioning Institute (HRAI) has issued resources for the changes in the 2024 OBC relevant to HVAC, click here to review the updates.
Harmonized with NBC requirements to enhance current OBC requirements. All pedestrian entrances to be barrier free accessible. Review the CSA Group Standard for Accessible Dwellings.
Updates to the Importance Category and Seismic Restraint matrices and terminology (e.g. seismic hazard index is replaced by seismic category. Find more information on this topic from the OAA here.
As part of Ontario’s commitment to modernize and streamline services, changes have been made to the list of applicable law in Ontario’s Building Code in relation to the Environmental Assessment Act and the Conservation Authorities Act. Read summaries of these changes here.
Additional Resources
Please note, that these have been generously shared by individual municipalities – the HCRA encourages you to check with your own local municipality on how they plan to interpret the new Code revisions, before starting any planning and permitting:
- Perth County municipalities overview on the 2024 OBC Changes
- City of Markham 2024 OBC overview
- Municipality of West Grey overview of Part 9 2024 OBC changes
- Municipality of Clearvier overview of 2024 OBC changes
- The City of Kitchener: Two sessions with an overview of changes to various aspects of the OBC:
The Canadian Board for Harmonized Construction Codes (CBHCC) has released complimentary illustrated resources for Housing and Small Buildings within the National Building Code (not all of the information will be applicable to the 2024 Ontario Building Code). These resources are accessible here.
Home-type care – Group B, Division 4 occupancies
Guard changes, including climbability – MMAH plans to prepare a guide on guards for the industry
Energy efficiency for houses and Large Buildings (did not adopt the NBC approach at this time), i.e. SB-10 and SB-12 will remain at this time
Tornado resiliency of houses (Ottawa & Barrie submissions post tornado)
Septic systems, chamber systems and new leaching bed types
Reminder that amendments related to stairs, guards and handrails came into effect on January 1, 2022. They were part of 2019 changes to the Building Code to further harmonize Ontario’s Building Code with the 2015 National Codes.