BCAB #1670 - Party Wall Construction in Duplex, Article 9.10.11.2.

May 13, 2010

BCAB #1670

Re: Party Wall Construction in Duplex, Article 9.10.11.2.

Project Description
The project in question consists of a number of side-by-side duplexes. Each half of each duplex sits on a parcel of land which is a separate real estate entity. These are not strata lots.

Reason for Appeal
Article 9.10.11.1. requires a party wall built on a property line to be constructed as a firewall except as permitted by Article 9.10.11.2. Article 9.10.11.2. allows that “in a building of residential occupancy in which there is no dwelling unit above another dwelling unit, a party wall on a property line between dwelling units 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.” A party wall is defined  as “a wall jointly owned and jointly used by 2 parties under easement agreement or by right in law, and erected at or upon a line separating 2 parcels of land each of which is, or is capable of being, a separate real-estate entity.”

Appellant’s Position
The appellant contends that the duplexes conform to the provisions of Article 9.10.11.2. because there is no dwelling unit above another dwelling unit, the fire separation will extend from the footing to the underside of the roof sheathing and be fire stopped. The appellant also contends each duplex is a single building because the two dwellings are separated by a party wall built as a fire separation, not a firewall, so the requirement of Article 1.3.3.4. of Division A to consider a structure on each side of firewall to be a separate building does not apply.

Building Official's Position
The building official maintains that Article 9.10.11.2. does not apply to a building which contains a dwelling unit beside another building which contains a dwelling unit but, rather, it applies to a building that contains multiple side-by-side dwelling units. As the property line effectively creates a separate building on each side of it. Article 9.10.11.2. does not apply. If it did then you could have series of 600 square metre buildings separated only by 1 hour fire separations instead of 2 hour firewalls and this cannot be the intent of the Code.

Appeal Board Decision #1670
It is the determination of the Board that Article 9.10.11.2. permits a 1 h fire separation on a property line separating side by side dwellings which are separate real estate entities and where there is no dwelling above another. This party wall is not considered as a firewall and does not create separate buildings for the purpose of building area. The Part 9 building area limit still applies and a 2 h firewall would be needed to limit buildings to not more than 600 sq m in building area.

George Humphrey, Chair