Construction of buildings using heavy timber construction, where Subsection 3.2.2. permits the building to be constructed of combustible construction.

This applies to buildings described in Sentence 1.3.3.2.(1) of Division A that contain portions of a floor area or mezzanines that do not terminate at an exterior wall, a firewall or a vertical shaft, and are required by Clause 3.2.8.1.(1)(b) to be protected in conformance with Articles 3.2.8.3. to 3.2.8.9.

This also applies to buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], where there are:

• openings through floors that are not protected by shafts or closures, as stated in Sentence 9.10.1.2.(6), or
• interconnected floor spaces, as stated in Sentence 9.10.9.5.(1).

Exceptions: 

To exclude heavy timber construction from the requirement in the beginning of Sentence 3.2.8.3.(1), which would otherwise require noncombustible construction, if the building is permitted by Subsection 3.2.2. to be of combustible construction, on the basis that this type of construction has an inherent resistance to collapse during the early stages of a fire and thus will not significantly contribute to the growth and spread of fire.