BCAB #1944 – Building Code Application to an Addition to an Existing Building

December 5, 2024

Re: Building Code Application to an Addition to an Existing Building

Project Description

An existing two-storey building contains a community centre and a theatre.  For this project, the theatre portion of the building is being demolished and is being replaced with a new three-storey theatre.

The community centre portion of the building (to be retained) has floors with a one-hour fire-resistance rating, noncombustible construction and a heavy timber roof, and it does not contain standpipes.  The theatre (to be demolished) is of combustible construction.  The two portions of the building were constructed at different times and are, based on a previous agreement, separated by a vertical fire separation having a two-hour fire-resistance rating.

At completion, the overall building, including the addition, will increase in building area from 3253 m² to 3378 m² and will increase in building height from two storeys to three, changing the construction classification of the original community centre portion.  The building will be sprinklered, will be of noncombustible construction, and will contain standpipes in the new portion.  The existing two-hour vertical fire separation is proposed to be removed.

Applicable Code requirements (BCBC 2024)

Sentence 1.1.1.1.(1), Division A, Application of this Code (excerpt)

(1) This Code applies to any one or more of the following:

(e) an addition to any building,

(j) the work necessary to ensure safety in parts of a building

(iii) that are affected by but not directly involved in additions,

Sentence 1.1.1.2.(1), Division A, Application to Existing Buildings

(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 Note A-1.1.1.2.(1).)

A-1.1.1.2.(1), Division A, Application to Existing Buildings. (excerpts)

This Code is most often applied to existing or relocated buildings when an owner wishes to rehabilitate a building, change its use, or build an addition, or when an enforcement authority decrees that a building or class of buildings be altered for reasons of public safety.  It is not intended that the British Columbia Building Code be used to enforce the retrospective application of new requirements to existing buildings or existing portions of relocated buildings, unless specifically required by local regulations or bylaws.  For example, although the British Columbia Fire Code could be interpreted to require the installation of fire alarm, standpipe and hose, and automatic sprinkler systems in an existing building for which there were no requirements at the time of construction, it is not [intended] that the British Columbia Fire Code be applied in this manner to these buildings unless the authority having jurisdiction has determined that there is an inherent threat to occupant safety and has issued an order to eliminate the unsafe condition, or where substantial changes or additions are being made to an existing building or the occupancy has been changed.  (See also Note A-1.1.1.1.(1) of Division A of the British Columbia Fire Code.)

Whatever the reason, Code application to existing or relocated buildings requires careful consideration of the level of safety needed for that building. This consideration involves an analytical process similar to that required to assess alternative design proposals for new construction. See Clause 1.2.1.1.(1)(b) for information on achieving compliance with the Code using alternative solutions.

In developing Code requirements for new buildings, consideration has been given to the cost they impose on a design in relation to the perceived benefits in terms of safety. The former is definable; the latter difficult to establish on a quantitative basis.  In applying the Code requirements to an existing building, the benefits derived are the same as in new buildings.  On the other hand, the increased cost of implementing in an existing building a design solution that would normally be intended for a new building may be prohibitive.

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.  The degree to which any particular requirement can be relaxed without affecting the intended level of safety of the Code requires considerable judgment on the part of both the designer and the authority having jurisdiction.

Decision being appealed (Local Authority’s position)

The new theatre addition will have the expected level of protection required by the new construction classification; however, the existing portion of the building could be compromised by an increased fire risk from the new theatre due to increased building height and building area.  Vertical fire separations are typically provided for building expansions and the existing building has a two-hour fire separation between the two structures.  Removing this fire separation to create unimpeded circulation between the existing and new space has warranted further quantitative analysis to demonstrate that the existing level of fire and life safety performance will not be reduced.  Analysis provided thus far is inadequate to demonstrate that the vertical fire separation at the interface can be removed when new portions of the building are made bigger and taller.

The increased level of fire and life safety risk from the larger new theatre and unprotected circulation openings in the interface between the existing community centre and the new theatre have not been fully addressed.  In absence of quantitative analysis, having a vertical fire separation between the existing community centre and the new theatre is the most direct method to reasonably maintain the existing level of fire and life safety performance for the existing community centre.

Appellant's position

The existing community centre is not within the current project scope.

There are no specific requirements, under either the Building Code or Fire Code, to bring existing buildings into compliance with the current Building Code, unless changes are proposed that would otherwise increase risk.  Sentence 1.1.1.2.(1), Division A, requires that where a building is altered, renovated, rehabilitated or repaired, the level of life safety and building performance shall not be decreased below a level that already exists.  Thus, the Building Code makes allowances for existing buildings and enables their useful life to be extended through additions, renovations, or changes of occupancy.  Note A-1.1.1.2.(1), Division A, states that application of the Building Code to existing buildings requires careful consideration of the level of safety needed for that building.  This consideration involves an analytical process similar to that required to assess alternative design proposals for new construction.

In new construction, the level of performance is established by the objectives and functional statements attributed to the acceptable solutions.  In existing buildings, the level of performance is established in Sentence 1.1.1.2.(1), Division A, and specifically requires that the alterations to the building not reduce the existing level of life safety and building performance.

Analysis is provided to demonstrate that the level of life safety and building performance in the existing community centre is maintained or improved.

The proposed addition will be constructed in accordance with the acceptable solutions in the 2024 Building Code.  The community centre has been examined based on the level of performance established in Sentence 1.1.1.2.(1), Division A, that specifically requires the addition of the new theatre not reduce the existing level of life safety and building performance in the existing community centre.  There is nothing related to the new theatre that negatively impacts the existing community centre on the basis that the new theatre is of noncombustible construction, has floors with a 2h fire resistance rating, is divided into multiple fire compartments, and is equipped with sprinklers and standpipes.

The need for separation of combustible and noncombustible construction that was previously addressed by the two-hour vertical fire separation has been eliminated with this project and the level of life safety and building performance in the community centre is maintained or improved.

Appeal Board Decision #1943

The Board varies the decision of the local authority.

It is the determination of the Board that the decision of the Local Authority focuses on an important requirement – that the level of fire and life safety in the community centre not be decreased – but the decision is fundamentally incomplete and requires reconsideration.

Work necessary to ensure safety in parts of the community centre that are affected by but not directly involved in additions must, to a degree established by an analytical process, comply with current code requirements.  This requirement is outlined in Subclause 1.1.1.1.(1)(j)(iii), Division A.  In addition, the entire community centre must comply with the requirement that the level of life safety and building performance not be decreased.  This requirement is outlined in Sentence 1.1.1.2.(1), Division A.

The project’s compliance with the current code requirements must be established.  Then, the Local Authority’s decision regarding compliance with the requirement that the level of life safety and building performance not be decreased must be reevaluated within that context.

Reason for decision

Fundamentally, the current requirements of the Building Code apply to the new theatre portion of the building (i.e., the addition) and they apply to the work necessary to ensure safety in parts of the community centre that are affected by but not directly involved in the addition.

As a further requirement, the level of life safety and building performance in the community centre (i.e., the existing portion of the altered or renovated building) must not be decreased below a level that already exists.  This second requirement is supplementary and neither supersedes nor negates the fundamental requirements.

The Board notes that neither the Appellant nor the Local Authority identify or establish that the project must comply, or complies, with the fundamental requirements in the existing portion as well as in the new portion, either by acceptable or alternative solutions.

In the new theatre, the required level of performance is established by the acceptable solutions in the areas defined by the objectives and functional statements attributed to the acceptable solutions.  In those portions of the community centre that are affected by but not directly involved in the addition, the required level of performance is also established by the acceptable solutions in the areas defined by the objectives and functional statements attributed to the acceptable solutions.  Further, any alteration of the community centre must not reduce the existing level of life safety and building performance.

Establishing the degree to which the affected portions of the existing community centre must comply with the fundamental code requirements requires considerable judgement on the part of both the Appellant and the Local Authority and the Board acknowledges the potential impracticality of fully applying all of the fundamental requirements to the portions of the existing community centre stipulated in the Code.

Once compliance with the fundamental requirements is established, then the parties will be in a position to reevaluate and identify what, if any, additional design and construction measures are necessary such that the requirement for no decrease in the life safety aspects or building performance of the community centre is satisfied.

This Decision is consistent with the principles applied and outlined in Appeal Board Decision #1779.

Don Pedde
Chair, Building Code Appeal Board