BCAB #1640 - Article Definition of Building (“umbrella” structure) Sentence, Structural Design Requirements (application to fabric “umbrella” structure )

January 30, 2008

BCAB #1640 

Re: Article Definition of Building (“umbrella” structure) Sentence, Structural Design Requirements (application to fabric “umbrella” structure )

(1998 BC Building Code)

Project Description

The subject is a structure of about 40 m2 in area ( 7 m diameter) which is proposed to be used as “on slope” café at a ski resort.  The structure has an octagonal fabric roof over a retractable metal frame supported by a single central column (similar to an umbrella).  The perimeter is semi enclosed by transparent panels about 2 m above the structure’s floor. The structure is assembled on an earth base, and does not have a permanent foundation.

The manufacturer has indicated the structure is designed for a maximum snow load of 0.3 KPa, with maximum snow accumulations of 200 mm.

Reason for Appeal

Part 4 indicates buildings and their structural members shall be designed to have sufficient structural capacity and structural integrity to resist safely and effectively all loads and effects of loads that may reasonably be expected. The Code defines a building as any structure used or intended for supporting or sheltering any use or occupancy.

Appellant’s Position

The appellant does not consider the structure to be a building as intended by the BC Building Code.

Further, should the structure be considered to be a building, the appellant feels the structure should be considered a temporary building and subject to exemption of Code requirements provided for in Clause (f).

Further, the appellant contends the umbrella stand is not required to meet the snow load requirements of Part 4 as it does not have a roof or other building surface subject to snow accumulation.

Building Official's Position
The Building Official considers the structure to be a building as defined by the Building Code as it is sheltering the occupancy of a licensed beverage establishment.

The authority having jurisdiction does not consider the structure to be a temporary building. The application to the authority indicated the structure may be occupied on a continual basis throughout the year, although the structure may be relocated to different sites throughout the resort area.

The design snow load at the resort area is 5.8 KPa. The building official recognizes the umbrella roof may be retracted to avoid excessive snow loads, or the snow could be cleared from the roof manually, but this is dependant on human intervention which is not considered equivalent to the Code’s requirements.

Appeal Board Decision #1640

It is the determination of the Board that the subject structure is considered a building as defined by the Building Code, as it shelters an occupancy. Exemptions such as size and temporary use, provided by Sentence were determined to be not applicable. Due to the unique nature of the building the Board suggests consultation with the authority having jurisdiction to meet Code requirements by alternative solutions acceptable to the authority.

George Humphrey, Chair