BCAB #1374 - Fire Separation of Townhouse Basement from Basement Storage Garage, Article 18.104.22.168. - 2. Exterior Exit Passageways with Dead End Sections, Sentences 22.214.171.124.(1) & (3), 126.96.36.199.(1) and 188.8.131.52.(1).
January 18, 1995
Re: 1. Fire Separation of Townhouse Basement from Basement Storage Garage, Article 184.108.40.206.
2. Exterior Exit Passageways with Dead End Sections, Sentences 220.127.116.11.(1) & (3), 18.104.22.168.(1) and 22.214.171.124.(1).
The project in question consists of three residential buildings over a basement garage.
The two storey townhouses in each of the three buildings have individual secured garages in the basement parking garage. Adjacent to each of these garages is a basement area for the townhouse above. A two hour concrete fire separation separates the parking garage from the buildings above and from the townhouse basements.
One of the buildings is 9 storeys high with exterior passageways serving the 3rd through 9th floors. On the 3rd and 4th floors only the passageways have dead end portions at each end that are less than 6 metres long.
Reason for Appeal
Article 126.96.36.199. permits a basement used primarily as a parking garage to be considered as a separate building for the purposes of Subsections 3.2.2., 3.2.4. and 3.2.6. provided the basement is fire separated from the building(s) above by a concrete floor with a two hour fire resistance rating.
With some exceptions Sentence 188.8.131.52.(1) requires exits to be fire separated from the adjacent floor area. One of these exceptions is an exterior walkway conforming to Sentence 184.108.40.206.(1). Exit facilities are also required by Article 220.127.116.11. to be protected from fire exposure from openings in the building's exterior walls.
The appellant contends that although Article 18.104.22.168. refers only to separating the buildings from the basement parking garage by a concrete "floor" with a two hour fire resistance rating, extending the fire separation down a wall between the parking basement and the townhouse basements follows the intent of the code. The appellant notes that this approach is consistent with Clause 22.214.171.124.(1)(b) which requires portions of the exterior basement wall within 3 metres of a firewall above to be concrete with no unprotected openings and a two hour fire resistance rating. This implies that a vertical two hour concrete fire separation can separate the basement garage from other buildings.
The appellant contends that an exterior exit passageway which combines portions that are fire separated from the adjacent floor area in conformance with Sentences 126.96.36.199.(1) and 188.8.131.52.(1) & (3) and not fire separated but in conformance with Sentence 184.108.40.206.(1) is acceptable. The exterior exit passageway in this project is more than 50% open on the exterior side and has an exit stair at each end except that on the fourth and fifth floors the passageway extends beyond the stair a short distance such that the end suites have only one direction of travel to reach the nearest exit stair. Therefore, these dead-end sections cannot meet the requirement of Sentence 220.127.116.11.(1) for an exit stair "at each end of the passageway" and will be fire separated from the adjacent floor area until a point opposite the nearest exit stair. From this point to the other exit stair the passageway conforms to Sentence 18.104.22.168.(1).
Building Official's Position
The building official maintains that the basement cannot be considered to be "used primarily as a storage garage" because it contains significant areas of residential use. Therefore, Article 22.214.171.124. is not applicable to this design and the basement must be considered as part of the building(s) above. An implication of residential use in the basement level is one of supervision of these areas. The occupants and the fire department can ensure that the low hazard nature of a storage garage is maintained but have no control over the residential areas of the basement.
The building official contends that the Code does not intend to permit an exterior exit passageway to conform to Sentence 126.96.36.199.(1) as well as Sentence 188.8.131.52.(1) and Article 184.108.40.206. The building official considers the treatment of exterior exit passageways are specifically detailed in the code and would take precedence over Sentence 220.127.116.11.(1) with regard to exits in combination.
Appeal Board Decision #1374
It is the determination of the Board that the basement is not primarily a storage garage and Article 18.104.22.168. cannot be applied. Article 22.214.171.124. requires buildings above a storage garage to be separated by a two hour fire rated concrete floor slab to be considered as separate buildings for the purposes of Subsections 3.2.2., 3.2.4. and 3.2.6. This design uses a wall for this purpose which is not in conformance with Article 126.96.36.199.
It is the determination of the Board that the design of the exterior exit passageway meets neither the 50% open requirement nor the stair at each end requirement so is not in conformance with Sentence 188.8.131.52.(1).
George R. Humphrey, Chair