Invoking the aurora borealis
WINNER OF ARCHITECTURAL AWARD
Architect: Randall Stout Architects, Inc.; HIP Architects, Associate Architect
Engineer: DeSimone Consulting Engineers
CISC Engineer: BPTEC-DNW Engineering Ltd.
CISC Steel Fabricator/Detailer/Erector: Empire Iron Works Ltd.
General Contractor: Ledcor Construction Ltd.
The project was a renovation of the existing concrete building to create expanded, flexible, museum-quality space for the gallery's permanent collection and major travelling exhibitions. The renovation consisted of a two-storey vertical addition above the existing building to contain gallery space and offices, and the addition of an atrium that exhibits the creative and dramatic use of steel to invoke the aurora borealis.
Structural steel was chosen because it minimized the impact on the existing structure, reduced loads on the foundation and provided unimpeded column-free interior space to maximize flexibility for exhibitions. The entire addition is supported by only six columns located on the north and south perimeters.
The building envelope of the atrium is formed from angular, transparent glazing planes penetrated by curving, reflective metal-clad elements that create the borealis.
Construction of the atrium presented numerous challenges due to the complex geometry, according to Trevor Hobbs, detailing and technical lead, Empire Iron Works.
"While the structure itself looks quite light and airy, we were dealing with heavy loads and members that had to line up with each other precisely," he points out. "Both exposed and concealed connections required special attention due to the 3-D aspect, the aesthetics and the close proximity of other building elements. This was most difficult where the skin fit tightly to the structure and restricted the space we could work with."
Some elements of structural steel were cantilevered through the skin. Says Hobbs: "Because steel is a good thermal conductor, this could compromise the museum quality space. The team resolved this issue by incorporating a thermal break in the steel at the point where it penetrates the building envelope and adding a non-conducting material in the joint to isolate the interior steel from the exterior steel."
A large measure of the success of the project is due to teamwork and the use of a variety of emerging techniques in 3-D modelling to coordinate and communicate the design details necessary for efficient site construction, Hobbs says.