BCAB 1957 - Construction of an exterior exit facility

Construction of an exterior exit facility

Project description

The project is the construction of a vertical and horizontal addition to an existing one-storey shopping centre such that a portion of the centre will now be two-storeys in building height.  The new second storey will contain offices.  A firewall separates the one- and two-storey portions of the centre.

One of the two required exits from the new second storey is provided by a new exterior door at the second storey that leads out to a new exterior landing and then down a new exterior metal stair.  The new exterior door at the top of the stair is identified on the drawings as one of the exits for travel distance purposes.  The new exterior stairs are variously identified as “Exterior Steel Staircase” and “Metal Fire Escape Stairs” on small scale plans, and as “Exit Stairs”, with a Code-compliant rise and run, on larger scale plans.

During construction the contractor determined, due to site constraints and operational requirements, that building the new exterior stair in compliance with the rise and run requirements for an exit stair was not feasible.  Construction in compliance with the rise and run requirements for a fire escape stair was completed instead.  The new stair has treads with rises of 190 mm and runs of 273 mm.

Applicable Code requirements (BCBC 2018)

Article 3.4.6.8., Division B, Treads and Risers

(1) Except as permitted for dwelling units and by Sentence 3.4.7.5.(1) for fire escapes, steps for stairs shall have a run of not less than 280 mm between successive steps.

(2) Steps for stairs referred to in Sentence (1) shall have

(a) a rise between successive treads not less than 125 mm and not more than 180 mm . . .

Article 3.4.7.1., Division B, Scope

(1) Except as permitted by Sentence (2), fire escapes shall not be erected on a building.

(2) If it is impracticable to provide one or more of the exit facilities listed in Article 3.4.1.4., fire escapes conforming to Articles 3.4.7.2. to 3.4.7.7. are permitted to serve floor areas in an existing building provided the floor areas served are not more than

(a) 2 storeys above ground level in care, treatment or detention occupancies, and

(b) 5 storeys above ground level in other occupancies.

Sentence 3.4.7.5.(1), Division B, Stairs

(1) Stairs shall be inclined at an angle of not more than 45° with the horizontal, and their steps shall have risers not more than 210 mm high and treads not less than 220 mm wide exclusive of nosing.

Decision being appealed (Local Authority’s position)

The second storey of the centre is a new floor area and consists of new construction added to an existing building.  Construction of exit facilities, complying with Code requirements for exits and according to the design, was not impracticable.

Appellant's position

Site constraints encountered during construction and operational requirements for fire lane clearance and forklift maneuvering made the construction of the exit stair design impracticable; the stair configuration was adjusted.  The labelling of the stair as a “Metal Fire Escape” contributed to the contractors understanding that compliance with the Code requirements for a fire escape would be acceptable.

The stairs are not intended to function as an entry to the second storey.  Egress from the second storey is supplemented by another exit stair and by a convenience stair.  The new exterior stair meets the intended function as an emergency exit from the second storey.

Appeal Board Decision #1957

The Board confirms the decision of the local authority.

It is the determination of the Board that the exterior steel staircase is required to comply with the Code requirements for an exit stair.

Reason for decision

The exterior steel staircase is one of two required exits from the second storey.  The convenience stair which passes through the firewall cannot be considered an exit because a horizontal exit must not include stairs.

The use of fire escape stairs may be permitted to serve floor areas in existing buildings where provision of exit facilities is impracticable.  The Board considers that the provision of the exit facility was not impracticable.

Don Pedde
Chair, Building Code Appeal Board
Dated: April 3, 2025