BCAB 1999 - Roof overhangs above a wall of a townhouse facing a property line

Roof overhangs above a wall of a townhouse facing a property line

Project Description

The project is the construction of a new townhouse building containing three residential units in a side-by-side configuration.  The building is regulated by Part 9.

One side of the building is located 1.22 m from a property line and a roof overhang at the top storey on that side is proposed to project 0.6 m into the setback area.  The overhang is proposed to be of combustible construction and the face of the overhang is proposed to be 0.62 m from the property line.

Applicable Code requirements (BCBC 2024)

Sentences 9.10.15.5.(5), (6), and (11), Division B, Construction of Exposing Building Face of Houses

(5) Except as provided in Sentence (6), combustible projections on the exterior of a wall that are more than 1 m above ground level and that could expose an adjacent building to fire spread shall not be permitted within 

(a) 1.2 m of a property line or the centre line of a public way, or
(b) 2.4 m of a combustible projection on another building on the same property.

(6) Except as provided in Sentences (8) to (11), Sentence (5) shall not apply to

(a) buildings containing one or two dwelling units only, and
(b) detached garages or accessory buildings, where

(i) the detached garage or accessory building serves only one dwelling unit,
(ii) the detached garage or accessory building is located on the same property as that dwelling unit, and
(iii) the dwelling unit served by the detached garage or accessory building is the only major occupancy on the property.

(See Note A-9.10.14.5.(7).)

(11) Where roof soffits project to less than 1.2 m from the property line, the centre line of a public way, or an imaginary line between two buildings or fire compartments on the same property, they shall

(a) have no openings, and
(b) be protected by

(i) not less than 0.38 mm thick sheet steel,
(ii) unvented aluminum conforming to CAN/CGSB-93.2-M, "Prefinished Aluminum Siding, Soffits, and Fascia, for Residential Use"
(iii) not less than 12.7 mm thick gypsum soffit board or gypsum ceiling board installed according to CSA A82.31-M, "Gypsum Board Application"
(iv) not less than 11 mm thick plywood,
(v) not less than 12.5 mm thick OSB or waferboard, or
(vi) not less than 11 mm thick lumber.

(See Note A-3.2.3.6.(2).)

Note A-9.10.14.5.(7), Division B, Permitted Projections.
The definition of exposing building face provided in Sentence1.4.1.2.(1) of Division A refers to “that part of the exterior wall of a building … or, where a building is divided into fire compartments, the exterior wall of a fire compartment …”  Because the exposing building face is defined with respect to the exterior wall, projections from exposing building faces are elements that do not incorporate exterior walls.  Depending on their specific configurations, examples of constructions that would normally be permitted by Sentence 9.10.14.5.(7) are balconies, platforms, canopies, eave projections and stairs.  However, if a balcony, platform or stair is enclosed, its exterior wall would become part of an exposing building face and the construction could not be considered to be a projection from the exposing building face.

Note A-3.2.3.6.(2), Division B, Protection of Roof Soffits Near Property Lines.
Sentences 3.2.3.6.(2) to (5) and parallel Sentences 9.10.14.5.(5) to (7) and 9.10.15.5.(5) to (7) provide requirements for the protection of soffits where the soffit of the subject building is located close to the property line or to an imaginary line between two buildings on the same property. Fire from inside the roof space of the subject building can exit unprotected soffits and expose the adjacent building to flames.

Decision being appealed (Local Authority’s position)

The subject roof overhang is located more than 1 m above ground level, could expose an adjacent building to fire spread, is within 1.2m of the property line, and is proposed to be of combustible construction.  A projection in that circumstance is not permitted, or it must be noncombustible.

Appellant's position

Article 9.10.15.5., Division B, regulates the construction of exposing building faces.  Roof overhangs should not be viewed as part of the exposing building face and may just be constructed in compliance with Sentence 9.10.15.5.(11), Division B.

Using noncombustible materials for similar roof overhangs is not a general practice in the region where the building will be located.

Appeal Board Final Decision #1999

The Board confirms the decision of the local authority.

It is the determination of the Board that Sentence 9.10.15.5.(5), Division B, applies to the roof overhang; any projection must not be combustible if it is within 1.2 m of the property line.

The subject building contains three dwelling units.  It therefore does not qualify for the exemption in Sentence 9.10.15.5.(6) which applies only to buildings containing one or two dwelling units.

Sentence 9.10.15.5.(11), Division B, applies to buildings that, due to the exemption provided in Sentence 9.10.15.5.(6), Division B, may have combustible projections.  Sentence 9.10.15.5.(11), Division B, does not override the requirement of Sentence 9.10.15.5.(5), Division B, and it does not permit the inclusion of the subject combustible projection.

Reasons for Final Decision

The requirements that limit or regulate the construction of combustible projections date back to the 1985 edition of the National Building Code of Canada (NBCC).  At that time, both Part 3 and Part 9 stated that:

“Except for buildings containing 1 or 2 dwelling units only, combustible projections on the exterior or a wall that are more than 1 m above ground level, such as balconies, platforms, canopies, eave projections and stairs, that could expose an adjacent building to fire spread, shall not be permitted within 1.2 m of a property line or an imaginary line between 2 buildings on the same property.”

Combustible projections on buildings containing one or two dwelling units received an unqualified exemption in the 1985 requirements.

In the 2010 edition, the NBCC changed the original unqualified exemption by adding specific requirements ¹ to address the potential for fire-spread between closely spaced soffits on buildings containing one or two dwelling units.  As part of the changes, the words “eave projections” were removed from the list of prohibited combustible projections in Part 3 ² and the “such as” list was removed entirely from Part 9 ³.

However, despite that the words “eave projections” no longer occur in the related Part 3 or Part 9 requirements, current Note A-9.10.14.5.(7), Division B, confirms that eave projections, which are permitted on buildings containing one or two dwelling units by virtue of Sentences 9.10.14.5.(7) and 9.10.15.5.(6), Division B, are a type of combustible projection that is prohibited by Sentence 9.10.15.5.(5), Division B.

The Board acknowledges that the rules regarding combustible projections are contained within an Article for which the head note is “Construction of Exposing Building Face of Houses”.  However, the BC Interpretation Act ⁴ stipulates that a head note “is not part of an enactment” (i.e., not part of the Code) and “must be considered to have been added editorially for convenience or reference only”.  Article 9.10.15.5., Division B, addresses the construction of exposing building faces plus other matters, including walls above exposing building faces, combustible projections, roof soffits and materials, and columns.

Don Pedde
Chair, Building Code Appeal Board

Dated:  June 4, 2026

 

¹ Those requirements are now relocated and an additional Sentence has been added.  See current Sentences 9.10.15.5.(8) to (11), Division B, along with corresponding Sentences in Article 3.2.3.6., Division B, and in Article 9.10.14.5., Division B.

² See current Sentence 3.2.3.6.(1), Division B, which no longer includes the words “eave projections”.

³ See current Sentences 9.10.14.5.(6) and 9.10.15.5.(5), Division B, which no longer include the words “such as balconies, platforms, canopies, eave projections and stairs”.

⁴ Interpretation Act, RSBC 1996, c 238