The Ontario Building Code | Change of Major Occupancy
11.4.2.3. Change of Major Occupancy
(1) Except as provided in Sentence 11.4.2.5.(4), the performance levelof an existing building is reduced where proposed construction will result in,
(a) the change of the major occupancy of all or part of an existing building to another major occupancyof a greater hazard index,
(b) the conversion of a suite of a Group C major occupancy into more than one suiteof Group C major occupancy,
(c) the conversion of a suite or part of a suite of a Group A, Division 2 or a Group A, Division 4 major occupancy into a gaming premises,
(d) the change of a farm building or part of a farm building to a major occupancy,
(e) the change of a building or part of a buildingto a post-disaster building,
(f) the change of a building or part of a buildingto a retirement home regulated under the Retirement Homes Act, 2010, or
Note: On July 1, 2017, Clause 11.4.2.3.(1)(f) of Division B of the Regulation is amended by striking out "a retirement home regulated under the Retirement Homes Act, 2010" and substituting "a retirement home". (See: O. Reg. 139/17, s. 140)
(g) the change in use of a building or part of a buildingwhere the previous major occupancyof the building or part of the building cannot be determined.
(2) For the purpose of this Article and Sentences 11.4.2.1.(1) and 11.4.2.5.(4), the change of use set out in Clauses (1)(b) to (g) is also deemed to constitute a change in major occupancy.
(3) The performance level of an existing buildingis reduced where the early warning and evacuation systems requirements of other Parts for the proposed major occupancy exceed those of the existing building.
(4) The performance level of an existing buildingis reduced where the proposed major occupancy in the building is not separated from the adjoining major occupancies by fire separations having fire-resistance ratingsconforming to Tables 3.1.3.1. and 11.4.3.4.B.
(5) The performance level of an existing buildingis reduced where the occupancy of all or part of an existing building of combustible construction is changed to a new major occupancythat would require the building, if it were a new building, to be of noncombustible construction or to be constructed in accordance with Article 3.2.2.43A. or 3.2.2.50A.
(6) Despite Clause (1)(a), the performance level of an existing building is reduced where proposed constructionwill result in the change of the major occupancy of all or part of an existing building to a Group C major occupancy in a building over 3 storeys in building height, except in a building conforming to Subclause 3.2.2.44.(1)(a)(ii) and having an egress facility conforming to Sentence 3.3.4.4.(8).