The project is a multi-storey mixed-use building incorporating recessed lighting fixtures in the ceilings. The housing for a recessed lighting fixture is proposed to penetrate a membrane that forms part of the floor/ceiling assembly required to have a fire resistance rating. The housing for the recessed lighting fixture was not incorporated in the assembly at the time of testing to determine its fire resistance rating.
Sentence 3.1.9.3.(5) of Division B of the 2012 British Columbia Building Code
3.1.9.3.(5) Combustible outlet boxes are permitted in an assembly required to have a fire-resistance rating without being incorporated in the assembly at the time of testing as required by Article 3.1.9.2., provided the opening through the membrane into the box is not more than 0.016 m².
The local authority has determined that housings for recessed lighting fixtures cannot be considered outlet boxes for the purposes of applying the exception of Sentence 3.1.9.3.(5).
The appellant maintains that the Code does not define the term outlet box. Outlet is defined in the B.C. Electrical Code as “a point in the wiring installation at which current is taken to supply utilization equipment.” The appellant considers that the recessed lighting fixture housing contains such a connection point, and thus the recessed lighting fixture housing can be considered as an outlet box.
It is the determination of the Board that the housing of a recessed lighting fixture cannot be considered an outlet box for the application of Articles 3.1.9.2. or 3.1.9.3.
The term outlet box is not defined in the BC Building Code and direction in Sentence 1.4.1.1.(1) of Division A is given that not defined terms “shall have the meanings that are commonly assigned to them in the context in which they are used, taking into account the specialized use of terms by the various trades and professions to which the terminology applies.” The term outlet box as used in the electrical trade generally does not include a luminaire/fixture.
There are a variety of housings for recessed lighting fixtures, and many of them do not have the characteristics of an outlet box considered in the testing that went towards the development of the Sentence 3.1.9.3.(5) relaxation. (Reference to the Minutes of the 10th Meeting of the Revision Subcommittee of the Standing Committee on Use and Occupancy, October 1978.)
Lyle Kuhnert
Chair, Building Code Appeal Board