One Spadina recently received an Award of Excellence from the Canadian Institute of Steel Construction (CISC) for its steel-framed roof — the building's signature architectural feature. Representatives from Entuitive, who worked with One Spadina designers NADAAA as the project’s structural engineer and building envelope consultants, were on hand to receive the award May 9.
The roof spans over 110 feet “across a column-less hall that will house the Faculty’s graduate design studios,” writes NADAAA on its blog. “A series of 3 cantilever trusses form the geometry for a modified ‘sawtooth,’ composed of clerestory windows that will admit high-quality northern light into the studios below.”
The architectural category of CISC’s awards honours buildings in which architectural considerations predominantly influenced the design of the structure. The bow-tie configuration of the steel trusses provide a total of eleven clerestory windows. The dramatic ceiling is its own landscape, determined by the structural, lighting and water drainage requirements. It creates a compelling civic interior and spectacular new platform from which to view the city and Spadina Avenue to the north.
Writes NADAAA on its blog:
The trusses themselves do not comprise a true span, in fact, they are 3 distinct structural components: two cantilevers and a link beam. As such, the trusses function like a cantilever bridge such as the Forth Bridge in Scotland (see also illustration below), or the Confederation Bridge which connects New Brunswick with Prince Edward Island. Cantilever bridges are characterized by greater structural depth aligned with the vertical supports, tapering to thin cantilevers at opposite ends between two adjacent spans. These twin cantilevers establish an equilibrium about the vertical support, balancing equal and opposite overturning forces.
Above: “Living model illustrating the principle of the Forth Bridge,” Coutesy of NADAAA