(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. and Sentences 3.2.5.13. (2) and (3), provided the floor and roof assemblies above the basement and, 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 rating of 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 encapsulated mass timber 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 or encapsulated mass timber 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.