The tallest building in Calgary and the tallest in Canada outside Toronto opens this week. The Bow is the new joint headquarters of natural gas and oil firm Encana and oil company Cenovus and has been designed by Foster + Partners to a breathtaking height of 237m. Anchored by a public base of retail units and restaurants, the tower curves inwards, facing south to exploit the strong daylight.
By turning the convex façade into the prevailing wind, the structural loading is minimised, thus reducing the amount of steel required for the inherently efficient diagrid system. Each triangulated section of the structure spans six storeys, helping to visually break down the scale of the building.
As Nigel Dancey, Senior Partner at Foster + Partners explains: “The tower’s form was shaped by the unique Calgary climate - facing south, the building curves to define a series of spectacular light-filled six-storey atria, with mature sky gardens, cafes and meeting areas, which bring a vital social dimension to the floor.
“This principle extends to the base of the tower, which is highly permeable with a +15 enclosed bridge connection to downtown, an atrium of shops and cafes and a fantastic new plaza. Every aspect, from the raised floors to the diagrid structure, is designed to be highly efficient. The Bow is a bold new symbol for Calgary, and is testament to the strength of our team and the excellent local relationships.”
As Dancey details, the integration of social spaces into The Bow was a key factor in the design of the tower. A series of sky gardens at levels 24, 42 and 54 offer generous spaces for informal meetings and social gatherings, and aim to enhance collaboration between colleagues. These internal sky gardens are each six storeys in height and feature mature trees, seating, catering and local lift cores to encourage employees to congregate.
This triplet of sky gardens project into a cavernous atrium which runs the full height of the building, acting as a climactic buffer and insulating the building in the chilly winter months. Enclosed walkways are connected to the tower at two points to enhance pedestrian access and to fully integrate the tower into the public realm. In the summer, both employees and the public can enjoy the sunshine in a new plaza at the base of The Bow, embraced in the south-facing curve of the building.