The Ontario Building Code | Buildings with Multiple Major Occupancies
3.2.2.4. buildings with Multiple Major Occupancies
(1) The requirements restricting fire spread and collapse for a building of a single major occupancyclassification are provided in this Subsection according to its building height and building area.
(2) If a building contains more than one major occupancy, classified in more than one Group or Division, the requirements of this Subsection concerning buildingsize and construction relative to major occupancyshall apply according to Articles 3.2.2.5. to 3.2.2.8.
Note: On July 1, 2017, Article 3.2.2.4. of Division B of the Regulation is amended by adding the following Sentence: (See: O. Reg. 139/17, s. 13)
(3) For the purposes of Sentences (1) and (2), a retirement homeis deemed to be a separate major occupancy.
In Plain Language
Buildings with more than one major occupancy generally still follow this Subsection's height/area rules, but which specific requirements apply is worked out via the cross-referenced Articles 3.2.2.5 to .8 rather than treating each occupancy in isolation.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.