11.4.2.3 — Change of Major Occupancy

(1) The performance level of an existing building is reduced where after proposed construction in all or part of an existing building, (a) the major occupancy will change to a different major occupancy, (b) the occupant load will increase by more than 15%, or (c) the live load will increase due to change in use within the same major occupancy, and the existing structural floor and roof framing systems and their supporting members after the construction are not adequate to support the proposed dead loads and live loads.

(1) The performance level of an existing building is reduced where the existing building is extended or subject to material alteration or repair and a sewage system serving the existing building is adversely affected by the extension, alteration or repair of the existing building. (2) Except as provided in Sentence (3), the performance level of an existing building is reduced where proposed construction will increase the occupant load of an existing building, and the new occupant load will result in the total daily design sanitary sewage flow of the building, calculated in accordance with Article 8.2.1.3., exceeding the capacity of any component of a sewage system serving the building. (3) The performance level of an existing dwelling unit is reduced where proposed construction that, (a) increases the number of bedrooms in the dwelling unit, (b) exceeds 15% of the finished area of the dwelling unit, or (c) adds new plumbing fixtures to the dwelling unit, will result in the total daily design sanitary sewage flow of the dwelling unit, calculated in accordance with Article 8.2.1.3., exceeding the capacity of any component of a sewage system serving the dwelling unit. (4) The performance level of an existing building is reduced where proposed construction will result in the change of a major occupancy of all or part of the existing building to another major occupancy and, (a) the total daily design sanitary sewage flow of the proposed major occupancy, calculated in accordance with Article 8.2.1.3., exceeds the capacity of any component of a sewage system serving the building, or (b) the type or amount of sanitary sewage which will, under the proposed major occupancy, be discharged to a sewage system serving the building, is prohibited by Article 8.1.3.1.

(1) Where the performance level of an existing building is reduced under Clause 11.4.2.3. (1)(a), (b), (c), (d), (e) or (g), additional upgrading shall be required in conformance with Table 11.4.3.4.A. and so that the construction index of the building is increased to at least equal the hazard index of the new major occupancy that the building is to support. (2) A building or part of the building subject to a change of major occupancy shall conform to the requirements of Subsection 3.2.6., Sections 3.7., 3.11., 3.12., Sentences 6.2.2.1. (2), 6.2.3.9. (1) and 6.2.4.7. (10), Subsections 9.5.1. and 9.5.3. to 9.5.10., Section 9.7., Subsection 9.10.17., Sections 9.31. and 9.32., and Subsections 9.34.1. to 9.34.3. as they apply to the new major occupancy that the building or part of the building is to support. (3) Where the performance level of an existing building is reduced under Sentence 11.4.2.3. (3), the building shall be evaluated, and the early warning and evacuation systems shall be upgraded, in conformance with the applicable requirements of Table 11.4.3.3. (4) Where the performance level of an existing building is reduced under Sentence 11.4.2.3. (4), upgrading of the fire separations shall be required in conformance with the applicable requirements of Article 3.1.3.1. and Table 11.4.3.4.B. (5) Where the performance level is reduced under Sentence 11.4.2.3. (5), the requirement for the building to be of noncombustible construction or to be constructed in accordance with Article 3.2.2.43A. or 3.2.2.50A. is satisfied if the building is sprinklered. (6) Where the performance level is reduced under Sentence 11.4.2.3. (6), the storey subject to the change shall be sprinklered. (7) Where the performance level of an existing building is reduced under Clause 11.4.2.3. (1)(f), the following requirements apply: (a) the retirement home shall be sprinklered, (b) a voice communication system conforming to Article 3.2.4.23. shall be provided in the building, and (c) doors to suites and sleeping rooms not within suites in the retirement home, other than doors leading directly to the exterior, shall be equipped with self-closing devices.

(1) A building classified as Group C, other than a retirement home, is permitted to conform to Sentence (2) provided, (a) it is sprinklered, (b) it is not more than 6 storeys in building height, (c) it has a height of not more than 18 m, measured between the floor level of the first storey and the floor level of the uppermost storey or mezzanine that is not a rooftop enclosure provided for elevator machinery, a stairway or a service room used for no purpose other than for service to the building, and (d) it has a building area of not more than, (i) 9 000 m2 if 1 storey in building height, (ii) 4 500 m2 if 2 storeys in building height, (iii) 3 000 m2 if 3 storeys in building height, (iv) 2 250 m2 if 4 storeys in building height, (v) 1 800 m2 if 5 storeys in building height, or (vi) 1 500 m2 if 6 storeys in building height. (2) The building referred to in Sentence (1) is permitted to be of combustible construction or noncombustible construction, used singly or in combination, and, (a) except as permitted by Sentence (3), floor assemblies shall be fire separations with a fire-resistance rating not less than 1 h, (b) roof assemblies shall have a fire-resistance rating not less than 1 h, (c) except as provided by Sentence (4), where the roof assembly has a height greater than 25 m measured from the floor level of the first storey to the highest point of the roof assembly, the roof assembly shall, (i) be of noncombustible construction, or (ii) be constructed of fire-retardant treated wood conforming to Article 3.1.4.5., (d) mezzanines shall have a fire-resistance rating not less than 1 h, (e) [[NO_FORMULA]] Revoked: O. Reg. 89/23, s. 7 (1). (f) loadbearing walls, columns and arches shall have a fire-resistance rating not less than that required for the supported assembly. (3) In a building that contains dwelling units that have more than 1 storey, subject to the requirements of Sentence 3.3.4.2. (3), the floor assemblies, including floors over basements, which are entirely contained within these dwelling units, shall have a fire-resistance rating not less than 1 h but need not be constructed as fire separations. (4) The construction of non-contiguous roof assemblies at different elevations is permitted to be evaluated separately to determine which roof assemblies are required to be constructed in accordance with Clause (2)(c). (5) Group A, Division 2 major occupancies, Group E major occupancies and storage garages located in a building or part of a building within the scope of this Article are permitted to be constructed in accordance with this Article, provided, (a) Group A, Division 2 major occupancies and Group E major occupancies are located below the third storey, and (b) storage garages are located below the fourth storey.

(1) A building classified as Group C, other than a retirement home, is permitted to conform to Sentence (2) provided, (a) it is not more than, (i) 3 storeys in building height, or (ii) 4 storeys in building height provided there is not more than one dwelling unit above another dwelling unit, and vertical fire separations of adjacent dwelling units conform to Sentence (4), and (b) it has a building area not more than the value in Table 3.2.2.44. (2) The building referred to in Sentence (1) shall be of noncombustible construction, and, (a) except as permitted by Sentence (3), floor assemblies shall be fire separations with a fire-resistance rating not less than 1 h, (b) mezzanines shall have a fire-resistance rating not less than 1 h, (c) roof assemblies shall have a fire-resistance rating not less than 1 h, and (d) loadbearing walls, columns and arches shall have a fire-resistance rating not less than that required for the supported assembly. (3) In a building that contains dwelling units that have more than 1 storey, subject to the requirements of Sentence 3.3.4.2. (3), the floor assemblies, including floors over basements, which are entirely contained within these dwelling units, shall have a fire-resistance rating not less than 1 h but need not be constructed as fire separations. (4) The dwelling units described in Subclause (1)(a)(ii) shall be separated by continuous vertical fire separations that extend through all storeys and service spaces of the separated portions. (5)[[NO_FORMULA]] Revoked: O. Reg. 139/17, s. 19.

(1) A building classified as Group D is permitted to conform to Sentence (2) provided, (a) it is sprinklered, (b) it is not more than 6 storeys in building height, (c) it has a height of not more than 18 m, measured between the floor level of the first storey and the floor level of the uppermost storey or mezzanine that is not a rooftop enclosure provided for elevator machinery, a stairway or a service room used for no purpose other than for service to the building, and (d) it has a building area of not more than, (i) 18 000 m2 if 1 storey in building height, (ii) 9 000 m2 if 2 storeys in building height, (iii) 6 000 m2 if 3 storeys in building height, (iv) 4 500 m2 if 4 storeys in building height, (v) 3 600 m2 if 5 storeys in building height, or (vi) 3 000 m2 if 6 storeys in building height. (2) The building referred to in Sentence (1) is permitted to be of combustible construction or noncombustible construction used singly or in combination, and, (a) floor assemblies shall be fire separations with a fire-resistance rating not less than 1 h, (b) roof assemblies shall have a fire-resistance rating not less than 1 h, (c) except as provided by Sentence (3), where the roof assembly has a height greater than 25 m measured from the floor level of the first storey to the highest point of the roof assembly, the roof assembly shall, (i) be of noncombustible construction, or (ii) be constructed of fire-retardant treated wood conforming to Article 3.1.4.5., (d) mezzanines shall have a fire-resistance rating not less than 1 h, (e) Revoked: O. Reg. 89/23, s. 8 (1). (f) loadbearing walls, columns and arches shall have a fire-resistance rating not less than that required for the supported assembly. (3) The construction of non-contiguous roof assemblies at different elevations is permitted to be evaluated separately to determine which roof assemblies are required to be constructed in accordance with Clause (2)(c). (4) Group A, Division 2 major occupancies, Group E major occupancies, Group F, Division 2 and 3 major occupancies and storage garages located in a building or part of a building within the scope of this Article are permitted to be constructed in accordance with this Article, provided, (a) Group A, Division 2 major occupancies, Group E major occupancies and Group F, Division 2 or 3 major occupancies are located below the third storey, and (b) storage garages are located below the fourth storey.

(1) Except as required by Sentence (8), single storey dwelling units in an apartment building need not lead to a public corridor or exterior passageway on the same storey provided the dwelling units are served by private stairways leading directly to a public access to exit on the storey, (a) immediately above, and (b) immediately below. (2) Except as required by Sentence (8) and as permitted by Sentences (3) and (4), a dwelling unit containing more than 1 storey shall have an exit door or an egress door opening directly into a public access to exit from the uppermost storey and from the lowest storey of the dwelling unit so that each storey is served by an exit or egress door located not more than 1.5 m above or below its floor level. (3) A single exit is permitted from a dwelling unit provided the exit is an exterior doorway not more than 1.5 m above adjacent ground level and, (a) it is not necessary to travel up or down more than 1 storey to reach the exit door, or (b) the uppermost floor level opens to a balcony not more than 6 m above adjacent ground level. (4) An egress door from either the uppermost storey or the lowest storey in a dwelling unit, as required in Sentence (2), need not be provided, (a) except as required by Sentence (8), if that storey is served by a stairway that, (i) leads to a public access to exit, (ii) has no direct access to any other storey in the dwelling unit, and (iii) is separated from the other storeys in the dwelling unit by a fire separation having a fire-resistance rating of not less than 45 min, (b) on the uppermost storey in the dwelling unit if the dwelling unit has not more than 2 storeys above the first storey of the building, (c) if it is not necessary to travel either more than 18 m or more than 1 storey up or down within the dwelling unit to reach the egress door, or (d) if that storey is, (i) provided with a balcony conforming to Sentence (7), (ii) not more than 2 storeys above or below the dwelling unit egress door, and (iii) in a building that is not more than 6 storeys in building height. (5) In a building of residential occupancy not more than 3 storeys in building height, a doorway from a dwelling unit is permitted to open directly into an exit stairway provided the dwelling unit has a second and separate means of egress. (6) If a dwelling unit has a second and separate means of egress, one means of egress from a dwelling unit is permitted to pass through, (a) an interior corridor served by a single exit, (b) an exterior balcony served by a single exit stairway, or (c) an exterior passageway served by a single exit stairway. (7) Where a balcony is provided to meet the requirements of Sentence (3) or (4), the balcony shall have, (a) a solid floor having a fire-resistance rating not less than that required for a floor assembly between suites, and (b) an area providing not less than 1.5 m2 per suite occupant, based on occupant load, and a minimum dimension of 1 200 mm. (8) Each dwelling unit in a building conforming to Subclause 3.2.2.44. (1)(a)(ii) shall be served by, (a) a direct exit that is an exterior doorway located not more than 1.5 m above adjacent ground level, or (b) a stairway that, (i) leads to an exterior doorway not more than 1.5 m above adjacent ground level, (ii) has no access to another dwelling unit, and (iii) is separated from the remainder of the building with a fire separation having a fire-resistance rating not less than 1 h.