The Ontario Building Code | Superimposed Major Occupancies
3.2.2.7. Superimposed Major Occupancies
(1) Except as permitted by Article 3.2.2.8. and Sentences 3.2.2.43A.(5) and 3.2.2.50A.(4), in a building in which one major occupancy is located entirely above another major occupancy, the requirements in this Subsection for each portion of the building containing a major occupancy shall apply to that portion as if the entire building was of that major occupancy.
(2) If one major occupancy is located above another major occupancy, the fire-resistance rating of the floor assembly between the major occupancies shall be determined on the basis of the requirements of this Subsection for the lower major occupancy.
Note: On July 1, 2017, Article 3.2.2.7. of Division B of the Regulation is amended by adding the following Sentence: (See: O. Reg. 139/17, s. 16)
(3) For the purposes of Sentences (1) and (2), a retirement homeis deemed to be a separate major occupancy.
In Plain Language
Where one major occupancy sits entirely above another, each portion of the building is treated, for fire-safety purposes, as if the whole building were that occupancy, and the floor assembly between them takes its fire-resistance rating from whichever occupancy is below.
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.