Which buildings fall under Part 9 of the Ontario Building Code?
Part 9 applies to buildings up to 3 storeys in building height and up to 600 m2 (6,458 sq ft) in building area, housing residential, business, mercantile or medium- and low-hazard industrial occupancies.
Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.
Part 9 is the prescriptive 'housing and small buildings' rulebook, covering nearly all detached houses, semis, townhouses, small apartment buildings, and small commercial buildings in Ontario. Staying inside its size and occupancy limits lets you follow span tables and standard details instead of hiring engineers for every element. Measure building height in storeys (not metres) and building area at the largest storey footprint. Mixed-use buildings qualify only if every major occupancy is on the permitted list.
Part 9 is the simplified part of the code for houses and small buildings. If your building is three storeys or less, no bigger than 600 m2, and is a home, shop, or office, Part 9 rules apply.
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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.