The Ontario Building Code | Storage Garage Considered as a Separate Building
3.2.1.2. Storage garage Considered as a Separate building
(1) A basement used primarily as a storage garage is permitted to be considered as a separate building for the purposes of Subsection 3.2.2., provided the floor and roof assemblies above the basementand, except as permitted by Sentence (2), the exterior walls of the basement above the adjoining ground level are constructed as fire separations of,
(a) masonry or concrete having a fire-resistance rating not less than 2 h, or
(b) noncombustible construction having a fire-resistance ratingof not less than 2 h, where the building conforms to Clauses 3.1.10.2.(4)(a) and (c) to (e).
(2) The exterior wall of a basement that is required to be a fire separation with a fire-resistance rating in accordance with Sentence (1) is permitted to be penetrated by openings that are not protected by closures provided,
(a) the storage garage is sprinklered,
(b) every opening in the exterior wall is separated from storeys above the opening by a projection of the floor or roof assembly above the basement, extending not less than,
(i) 1 m beyond the exterior face of the storage garage if the upper storeys are required to be of noncombustible construction, or
(ii) 2 m beyond the exterior face of the storage garage if the upper storeys are permitted to be of combustible construction, or
(c) the exterior walls of any storeys located above the floor or roof assembly referred to in Sentence (1) are recessed behind the outer edge of the assembly by not less than,
(i) 1 m if the upper storeys are required to be of noncombustible construction, or
(ii) 2 m if the upper storeys are permitted to be of combustible construction.
(3) The floor or roof assembly projection referred to in Clause (2)(b) shall have a fire-resistance rating not less than 2 h and shall have no openings within the projection.
In Plain Language
A basement used mainly as a storage garage can be treated as a separate building for classification purposes, provided the floor/roof assemblies above it and its above-ground exterior walls are built as 2-hour-rated fire separations of masonry, concrete, or noncombustible construction meeting the specific conditions described.
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.