June 21, 2018
Re: Code Application to New Construction Within an Existing Building
The project is an alteration to the basement of one side of an existing duplex. The alteration reconfigures the basement room layout which adds an additional room. The alteration includes changes to existing stair configuration, changes to interior finish of existing exterior walls, structural modifications, interior framing and finishing.
Applicable Code Requirement
Sentence 220.127.116.11.(1) of Division A of the 2012 British Columbia Building Code
18.104.22.168.(1) Where a building is altered, rehabilitated, renovated or repaired, or there is a change in occupancy, the level of life safety and building performance shall not be decreased below a level that already exists. (See Appendix A.)
Decision being Appealed (Local Authority’s Position)
The local authority has determined that substantial changes are being made to an existing building and that the alteration is to conform to the 2012 British Columbia Building Code (BC Building Code). The current requirements in the BC Building Code would require insulation in exterior walls to be upgraded, that joist spaces require insulation, that a Code compliant polyethylene vapour barrier is required, that interconnected smoke detectors and carbon monoxide detectors are required, and that the existing bathroom is to have an exhaust fan.
The appellant maintains that the alteration does not decrease the level of building performance below that which already exists, and therefore the Code provisions identified by the authority having jurisdiction are not required.
Appeal Board Decision # 1811
It is the determination of the Board that Sentence 22.214.171.124.(1) does not give permission or supersede the application statement of Clause 126.96.36.199.(1)(d) that states the Code applies to an alteration of a building. Those aspects of the project that are directly altered or newly constructed are required to comply with the current BC Building Code requirements. Those parts of the building which are not altered or newly constructed do not need to comply with current requirements, provided they were compliant with the applicable Building Code requirements in force at the time of construction.
For example, the stairs being newly constructed/altered must meet current Code requirements, whereas, provided the insulation was pre-existing, it would not have to be upgraded to current Code requirements.
Reason for Decision
The BC Building Code gives little guidance on the application of the Code to existing buildings. However, it does provide some commentary in A-188.8.131.52.(1) which the Board has considered.
A-184.108.40.206.(1) states “The successful application of Code requirements to existing construction becomes a matter of balancing the cost of implementing a requirement with the relative importance of that requirement to the overall Code objectives.”
Chair, Building Code Appeal Board