BCAB 2006 - Fire separation of residential roof-top decks

Fire separation of residential roof-top decks

Project Description

The project is the design and construction of a new three-unit rowhouse under Part 9.  The building will be sprinklered, and will contain no stacked units or secondary suites.  During the project, the property will be subdivided into three parcels; property lines will be added between units and the walls between units will be party walls.

Each of the three units will have an exterior rooftop deck accessed by an internal stair leading up from the storey below.  A 1.8m high privacy screen is located between two of the roof decks.

The configuration is generally as illustrated below:

Applicable Code requirements (BCBC 2024)

Clause 9.10.9.1.(1)(a), Division B, Application

(1) This Subsection applies to

(a) fire separations required between rooms and spaces in buildings, except between rooms and spaces within a dwelling unit, and . . .

Sentence 9.10.9.16.(3), Division B, Separation of Residential Suites

(3) Except as provided in Sentence (4), dwelling units that contain 2 or more storeys including basements as well as houses with a secondary suite including their common spaces shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 1 h. (See Note A-3.3.4.4.(1).)

Clause 9.10.11.2 (1)(a), Division B, Firewalls Not Required

(1) A party wall on a property line of a building of residential occupancy need not be constructed as a firewall, provided it is constructed as a fire separation having not less than a 1 h fire-resistance rating, where the party wall separates

(a) two dwelling units where there is no dwelling unit above another dwelling unit, . . .

Decision being appealed (Local Authority’s position)

The rooftop deck areas are occupied spaces.  Adjacent rooftop deck occupancies must be protected by a vertical continuation of party wall having a 1 hour fire-resistance rating.  An unrated privacy screen or wall does not satisfy the Code requirement.

Appellant's position

The Code does not require fire separations at exterior spaces, regardless of the space having an occupancy.  The requirements for fire separations in buildings do not apply at the exterior roof decks.

The privacy divider is not subject to party wall or firewall requirements, is not required to be a fire separation, and is not required to have a fire-resistance rating.

Appeal Board Final Decision #2006

The Board  reverses the decision of the local authority.

It is the determination of the Board that the privacy divider is not subject to party wall or firewall requirements, is not required to be a fire separation, and is not required to have a fire-resistance rating.

Reason for Final Decision

The purpose of a fire separation is to enclose a fire compartment and to act as a barrier against the spread of fire.  At an open rooftop, a fire separation would not enclose a fire compartment or meaningfully contain a fire.  A rooftop fire separation would serve no practical purpose and the Code does not require a fire separation in that location.

Don Pedde
Chair, Building Code Appeal Board 

Dated:  August 6, 2026