Things are rapidly changing at The One, the future 85-storey luxury condo, hotel, and retail complex at Yonge and Bloor in the heart of Toronto. The project from Mizrahi Developments is set to stand out from the pack with a 308.6-metre height that should be Canada's tallest building when completed, and a striking design incorporating a unique structural system from UK-based starchitects Foster + Partners working with Toronto's Core Architects.

Looking southwest across the corner of Bloor and Yonge to the new 'supercolumns' being raised at The One, image by UT Forum contributor Rascacielo

The project broke ground three years ago, and after a lengthy excavation, the first hints of the tower's future hybrid exoskeleton were revealed when massive augers drilled boreholes for 'mega-caissons' that would be installed deep into the bedrock. These enormous structural elements were continued through the complex's underground parking levels as 'supercolumns' before surfacing at street level earlier this year. Eight rust-coloured steel caps were then affixed to them, priming the next steps in the structural system.

Aerial view of The One, image by Forum contributor Benito

When we last checked in a couple weeks ago, the first of eight canted steel columns were being installed, resting on yellow-painted temporary steel supports. These columns will transfer loads down through the lowest three floors from the building's elevator core to meet the supercolumns around the building's perimeter. The 'floating' of the elevator core will keep the complex's primary retail space's floor-plate column free for a wide-open retail space at ground level.

View of ground floor at The One, image by Forum contributor Benito

In the days since that update, the remaining ground-floor canted columns have been installed, and have been joined by raising of the eight vertical supercolumns by a few more floors. These 40-tonne column sections now delineate the height of this ground floor retail space. While aerial views offer a good overview of the supercolumns' layout, a view from closer to the ground is required to show off the true scale of these columns.

Looking west across Yonge to The One, image by Forum contributor androiduk

Sixteen more steel caps have been attached to the tops of the canted columns as well as the first supercolumn sections. These mark where the next group of canted columns will attach, and transfer loads through the upcoming second-floor restaurant/event space. A shot of one of the supercolumns awaiting installation shows off the angled plates in detail, while also showing off the tremendous girth of the supports.

View of megacolumn awaiting installation at The One, image by Forum contributor Benito

As the structural system reveals itself on the future tower footprint, additional above-grade progress is being recorded, including concrete walls for banks of elevators now being formed along the west edge of site (to the right, in the image below).

View facing south over The One, image by UT Forum contributor AdamS

In conditions that evoke the 1930s race for the tallest in New York City, The One is one in a growing group of projects vying for the title of Canada's tallest building. While others are in the running for this crown, The One's high base elevation, slender pencil-like massing, and a structural system on display to the skyline will all help to maintain the building's skyline impact well into the future.

The One, image courtesy of Mizrahi Developments

Additional information and images can be found in our Database file for the project, linked below. Want to get involved in the discussion? Check out the associated Forum thread, or leave a comment in the space provided on this page.

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Related Companies:  A&H Tuned Mass Dampers, Core Architects, Doka Canada Ltd./Ltee, Live Patrol Inc., McIntosh Perry, Mizrahi Developments, NEEZO Studios, Rebar Enterprises Inc, RJC Engineers, Terraprobe Inc, The Planning Partnership, VDF Vertical, Walters Group, XORTUS Scale Models