National Building Code of Canada - Section 201

3.2.2.51. Division B 3.2.2.51. Group C, up to 6 Storeys, Sprinklered 1) A building classified as Group C 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 not more than 18 m measured between the floor of the first storey and the uppermost floor level that does not serve a rooftop enclosure for elevator machinery, a stairway or a service room used only for service to the building,and d) it has a building area not more than i) 9 000 m 2 if 1 storey in building height , ii) 4 500 m 2 if 2 storeys in building height , iii) 3 000 m 2 if 3 storeys in building height , iv) 2 250 m 2 if 4 storeys in building height , v) 1 800 m 2 if 5 storeys in building height,or vi) 1 500 m 2 if 6 storeys in building height . 2) Buildings referred to in Sentence (1) are permitted to be of combustible construction or noncombustible construction , used singly or in combination, and a) except as provided in 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 in Sentence (4), where the roof assembly has a height greater than 25 m measured from the floor of the first storey to the highest point of the roof assembly, the roof assembly shall be constructed of noncombustible construction or fire-retardant-treated wood conforming to Article 3.1.4.5., d) mezzanines shall have a fire-resistance rating not less than 1 h, and e) 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 one storey ,subject to the requirements of Sentence 3.3.4.2.(3), the floor assemblies, including those over basements , that 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) Where buildings conforming to Sentence (2) include non-contiguous roof assemblies at different elevations, the roof assemblies are permitted to be evaluated separately to determine which ones are required to be constructed in accordance with Clause (2)(c). 5) Group A, Division 2 major occupancies ,GroupE major occupancies ,and storage garages located in a building or part thereof within the scope of this Article are permitted to be constructed in accordance with this Article, provided a) the Group A, Division 2 major occupancy and Group E major occupancy are located below the third storey ,and b) the storage garage is located below the fourth storey (see also Article 4.4.2.1.). (See Note A-3.2.2.51.(5) and 3.2.2.60.(4).) 3.2.2.52. Group C, up to 4 Storeys, Sprinklered 1) A building classified as Group C is permitted to conform to Sentence (2) provided a) except as permitted by Sentences 3. 2.2.7.(1) and 3.2.2.18.(2), the building is spr i nklered , b) it is not more than 4 storeys in building height,and c) it has a building area not more than i) 7 200 m 2 if 1 storey in building height , ii) 3 600 m 2 if 2 storeys in building height , iii) 2 400 m 2 if 3 storeys in building height ,or iv) 1 800 m 2 if 4 storeys in building height . 3-62 Division B National Building Code of Canada 2025 Volume 1