May 02, 2024
The project is a new building, proposed to contain six storeys of combustible construction
- residential occupancy – over two storeys of noncombustible construction – storage garage.
Retaining walls at various locations around the building are proposed, artificially adjusting
finished ground levels and establishing grade such that the building would be seven storeys in
building height, with the floor of the top storey located 19.69 m above grade.
An alternative solution is proposed to address combustible construction requirements and high
building measures.
Sentence 1.2.1.1.(1), Division A, Compliance with this Code
(1) Compliance with this Code shall be achieved by
a) complying with the applicable acceptable solutions in Division B (see Note A- 1.2.1.1.(1)(a)),
or
b) except as required by Sentence (3), using alternative solutions, accepted by the authority
having jurisdiction under Section 2.3. of Division C, that will achieve at least the minimum level
of performance required by Division B in the areas defined by the objectives and functional
statements attributed to the applicable acceptable solutions (See Note A-1.2.1.1.(1)(b)).
Sentence 1.4.1.2.(1), Division A, Defined Terms
Building area means the greatest horizontal area of a building above grade within the outside
surface of exterior walls or within the outside surface of exterior walls and the centre line of
firewalls.
Building height (in storeys) means the number of storeys contained between the roof and the floor
of the first storey.
Grade means the lowest of the average levels of finished ground adjoining each exterior wall of a
building, except that localized depression need not be considered in the determination of average
levels of finished ground. (See First storey and Note A- 1.4.1.2.(1).)
Article 3.2.2.47., Division B, Group C, Any Height, Any Area, Sprinklered
1) Except as permitted by Articles 3.2.2.48. to 3.2.2.55., a building classified as Group C
shall conform to Sentence (2).
2) Except as permitted by Article 3.2.2.16., the building referred to in Sentence (1) shall be of noncombustible construction . . .
Article 3.2.6.1., Division B, Application
1) Except as provided in Sentence (2), this Subsection applies to a building
d) containing a Group C major occupancy whose floor level is more than 18 m above grade.
After manipulation of grade the building will be more than six storeys in building height and the distance between the floor levels of the first and uppermost storeys will exceed 18 m. Also, the building area exceeds 1 500 m2. Therefore, the building does not fit within the acceptable solution outlined in Article 3.2.2.51., Division B. Articles 3.2.2.47. or 3.2.2.48., Division B, provide the acceptable solutions and, based on the alternative solution approach, the building will not perform as well as one constructed in compliance with the acceptable solutions.
Further, the distance from grade to the uppermost floor level exceeds 18 m. Requirements outlined in Subsection 3.2.6., Division B, are the acceptable solutions, all are relevant and interdependent, and all must be addressed by acceptable or alternative solutions.
The User’s Guide indicates that altering of grade can be undertaken, specifically to address building height for construction and/or high building requirements, provided that care is taken that the alteration does not negatively impact exiting or firefighting. In this case, alteration of grade results in a seven-, rather than eight-storey, building, and an uppermost floor level at 19.69 m above grade rather than approximately 21 m. The proposed alternative solution will fully address these situations.
The alternative solution proposes measures to address the noncombustible construction requirements found in Article 3.2.2.47., Division B. Further, the alternative solution evaluates and addresses the high building measures outlined in Subsection 3.2.6., Division B, and, given the unique building configuration, identifies those that may not provide benefit commensurate with their cost.
The alternative solution will provide a level of performance that is suitable for a building that marginally exceeds the limits set out in Article 3.2.2.51. and Subsection 3.2.6., Division B, and will fully address each parameter in which the building exceeds those limits.
The Board confirms the decision of the local authority.
It is the determination of the Board that the approach taken in the alternative solution proposal will not result in a building that will achieve at least the level of performance required by Clause 1.2.1.1.(1)(b), Division A.
Reason for decision
The Board considers the alternative solution must achieve at least the minimum level of performance required by Division B in areas defined by the objectives and functional statements attributed to the applicable acceptable solutions, in this case Article 3.2.2.47., Division B (or possible alternate) and Subsection 3.2.6., Division B.
This decision is consistent with the principles applied in previous Appeal Board decisions #1754 and #1889.
Don Pedde
Chair, Building Code Appeal Board