At 340.6 m tall, The ONE is Canada’s tallest building and one of the most slender supertall towers in the world. The design, by London-based Foster and Partners with the Toronto firm Core Architects, is a three-part composition: Retail at ground level and restaurant space, reaching up through eight levels and features a public atrium; above that, a box containing the tower’s mechanicals; and on top, a residential tower. With a total of 84 storeys, the condo floors are highly flexible and the retail space (more than 240,000 sq. ft.) is free of structural columns, with 22-foot ceilings. The signature design highlights a unique exoskeleton structural system that dramatically reshapes Toronto’s skyline.