This week, Alex Bozikovic (of the Globe and Mail) dropped the news that a new supertall by Herzog & de Meuron is being planned for the northwest corner of Bay and Bloor here in Toronto. The developers are Kroonenberg Group and ProWinko, both of which are based / have their roots in the Netherlands. At 87 storeys and 324 meters, it would be the tallest building in Canada if it were built today. The proposal includes retail, office, and residential uses.
The first thing that everybody is talking about is the tower’s slenderness ratio (the upper floors are said to be about 7,300 square feet). I’m not a structural engineer, but the structural engineers that I do know are telling me that this tower will almost certainly require a tuned mass damper at the top of the building for lateral stiffness. The tower is very narrow in its east-west direction (see below) and so it will perform as a kind of “sail” in the wind. But as New York and other cities have shown us, this can be done.
Another feature of this building is its double skin facade. As far as I know, this would be the first residential building in Toronto to have one (please correct me if I’m wrong). In fact, the only building that I can think of off the top of my head is the Donnelly Centre for Cellular and Biomolecular Research, University of Toronto by Behnisch Architekten and architectsAlliance. (For the record, and as far as I know, I am not related to the donor for this building — but what a great last name.)
Usually the idea behind a double skin facade is to create an air cavity between both skins and then ventilate it. To reduce cooling loads in the summer, shading devices are also usually added within this air cavity. The system works by trapping and then extracting solar heat gain before it reaches the inside of the building. Engineers and real architects tell me that this generally works a lot better than a typical interior blind, because at that point you’ve already let a lot of the heat inside of your conditioned space.
I am a big fan of ambition. And this project is certainly ambitious. For more about the proposal, check out the Globe and Mail.
Update: This project is being done in collaboration with Quadrangle Architects of Toronto.
Images: Herzog & de Meuron