CISC Ontario Awards 2010

The additional residential levels situated on top of the tower exceeded the capacity of both the existing structural frame and the existing foundations. The key to the development of the new space was the reinforcing program applied to the existing structure. With virtually every design challenge, the application of structural steel provided a solution that was significantly better than the alternative design option.

At the basement level, the capacity of the existing spread footings were enhanced without compromising the use of the space for parking, without impacting the adjacent subway lines, and without adversely affecting the retail space directly overhead. Within the existing retail and office space, selected tower columns were reinforced, beams strengthened and vertical steel bracing applied at all levels in order to support the increased vertical and lateral loading. Above the existing building, long-span transfer trusses were placed just above the existing roof, ensuring that the historic penthouse apartment interiors would be preserved in keeping with the design intent.