BCAB #1915

October 5, 2023

Re: Smoke Control at Vestibules in a High Building

Project Description

The project is a six-storey building on a one-storey basement. The building contains care occupancies above the third storey; additional requirements for high buildings apply. The exit storey is the ground floor/first storey. Elevators extend from the basement up to
multiple storeys above.

The basement storage garage contains vestibules between the parking area and the elevator shafts.

Applicable Code requirements (BCBC 2018)

Article 3.2.6.2., Division B, Limits to Smoke Movement
(4) Measures shall be taken to limit movement of smoke from a fire in a floor area below the lowest exit storey into upper storeys. (See Note A-3.2.6.2.(4).)

Note A-3.2.6.2.(4), Division B, Limiting Smoke Movement. Measures to prevent the migration of smoke from floor areas below the lowest exit storey into upper storeys include the following.
1) An elevator hoistway that passes through the floor above the lowest exit storey should not penetrate the floor of the storey immediately below the lowest exit storey, unless there is a vestibule between the shaft and each floor area below the lowest exit storey that
a) has a fire separation, with a fire-resistance rating not less than 45 min, between the vestibule and any public corridor, […]

Decision being appealed (Local Authority’s position)

Smoke control measures are necessary for every floor area located below the lowest exit storey. The provision of vestibules between the parking areas and elevator shafts would be an acceptable way to satisfy the requirement provided that the walls separating the vestibules from the parking area are constructed as fire separations having fire resistance ratings not less than those required for the exits. The Local Authority provides interpretation No. 12-0051, dated December 2018, prepared by the BC Building Code Interpretation Committee in support of their decision.

Appellant's position

Only the one-storey basement storage garage storey is located below the lowest exit storey and the elevator shafts do not penetrate the floor of the storage garage. Therefore, the walls separating the vestibules from the parking area do not require a fire- resistance rating. The Appellant provides BCAB Appeal #1677 in support of their position.

Appeal Board Decision #1915

The Board confirms the decision of the local authority. It is the determination of the Board that the walls separating the vestibules from the parking area must be constructed as fire separations having fire resistance ratings not less than those required for the exits.

Reason for decision

The Code requires that measures be taken to limit movement of smoke from a fire in a floor area below the lowest exit storey into upper storeys. The Board considers the storage garage to be a floor area below the lowest exit storey.

Don Pedde
Chair, Building Code Appeal Board