KPMB; Adamson Associates
Tower: 980 000 ft2, Podium: 100,000 ft2
Building Envelope Consultant
At 44 storeys plus an eight-storey podium, Toronto’s Bay Adelaide Centre East is a LEED® Platinum project that demands significant structural innovation to bring to fruition.
The heritage component of the project involves preserving and relocating on the site façades of a four-storey stone and brick structure built in 1850 as well as restoration and repair of the existing masonry including developing a period-style window frame to replace the existing windows.
The tower core is built using an ATR self-climbing system – so-called because it climbs on rails up the building by means of hydraulic jacks – so construction can proceed without the use of a tower crane. The project posed significant challenge in maintaining an active PATH system, retail and operational 4 storey parking garage during construction. To mitigate noise and vibration from an adjacent subway line, crews built the ground floor of the podium so that its core floats 100 millimetres above the existing B1 level. It is supported on existing columns and foundation walls using isolation pads.
Challenge: Preserve and move three individual sections of the façade from heritage buildings to a location on the opposite side of the site while preserving the brick masonry of the facades and protect against excessive moisture from the cooling towers located directly behind the relocated facades.
Solution: Through extensive hygrothermal modelling and analysis of the conditions the heritage walls would face in their new location, we recommended a dynamic buffer zone (DBZ) for the areas directly behind the heritage walls assemblies. The DBZ would provide the separation and protection from high levels of humidity for which the masonry was not accustom to in its prior location and extend the potential life of the wall with a modest amount of maintenance while increasing the performance of the building envelope.