National Building Code of Canada - Section 921

9.10.10.5. Division B 2) Except as required in the appliance installation standards referenced in Sentences 6.2.1.5.(1), 9.33.5.2.(1) and 9.33.5.3.(1), fuel-fired space-heating appliances, space-cooling appliances , service water heaters and laundry appliances need not be separated from the remainder of the building as required in Sentence (1), a) where the appliances serve i) not more than one room or suite ,or ii) a building with a building area of not more than 400 m 2 and a building height of not more than 2 storeys,or b) where the appliances i) serveahousewitha secondary suite including their common spaces, and ii) are located in a service room where both sides of any wall assemblies and the underside of any floor-ceiling framing separating this room from both dwelling units or their common spaces are protected by a continuous smoke-tight barrier consisting of not less than 12.7 mm thick gypsum board. 3) Sentence (1) does not apply to fireplaces and cooking appliances . 9.10.10.5. Incinerators 1) Service rooms containing incinerators shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 2 h. 2) The design, constru ction, installation and alteration of each indoor incinerator shall conform to NFPA 82, “Standard on Incinerators and Waste and Linen Handling Systems and Equipment.” 3) Every incinerator shall be connected to a chimney flue conforming to the requirements in Section 9.21. and serving no other appliance . 4) An incinerator shall not be located in a room with other fuel-fired appliances . 9.10.10.6. Storage Rooms 1) Rooms for the temporary storage of combustible refuse and materials for recycling in all occupancies or for public storage in residential occupancies shall be separated from the remainder of the building by a fire separation having not less than a 1h fire-resistance rating , except that a fire separation with a fire-resistance rating of not less than 45 min is permitted where a) the fire-resistance rating of the floor assembly is not required to exceed 45 min, or b) the room is sprinklered . 9.10.11. Firewalls 9.10.11.1. Required Firewalls 1) Except as provided in Article 9.10.11.2., a party wall on a property line shall be constructed as a firewall . (See Note A-3.2.3.4.(1).) 9.10.11.2. Firewalls Not Required 1) Except as stated in Sentence (2), a party wall on a property line of a building of residential occupancy need not be constructed as a firewall, provided it is constructed as a fire separation having not les sthana1hfire-resistance rating , where the party wall separates a) two dwelling units where there is no dwelling unit above another dwelling unit , b) a dwelling unit and a house with a s econdary suite including their common spaces, or c) two houses with a secondary suite including their common spaces. 2) Where a building of residential occupancy contains more than 2 houses, a party wall that separates any 2 adjacent houses with a secondary suite from the rest of the 9-60 Division B National Building Code of Canada 2025 Volume 2