The Beautiful Bow, Calgary, Alberta

Tetra Tech helped address energy efficiency concerns in Canada’s largest building west of Toronto.


  • Size: 2,000,000 square feet (185,806 square meters)
  • Client/Owner: H+R Real Estate Investment Trust, Matthews Southwest Developments
  • Architect: Foster + Partners, Zeidler Partnership Architects, Gensler

The Bow office tower, headquarters of Encana and Cenovus in Calgary, Alberta, was named after the nearby Bow River and in recognition of the tower’s curving shape. The project is 59 stories high and has a gross area of 2,000,000 square feet, including 800,000 square feet of parking. The glass-and-steel building dominates the city’s downtown skyline and is the largest building in Canada west of Toronto.

Tetra Tech’s High Performance Buildings Group incorporated unique design features to maximize energy efficiency. Tetra Tech proposed and designed an underfloor air distribution system using air tower units, underfloor fan-powered boxes, and floor-mounted swirl diffusers to address energy efficiency, occupant comfort, and a substantial reduction in total ownership costs.

EnCana’s researchers required complex three-dimensional (3-D) visualization studios. Scientists collect vast amounts of data in the field to create 3-D images of underground geological formations and pockets where gas, oil sands, or oil might be located. The 3-D stereoscopic display technology that Tetra Tech designed allows for a close study of the underground geology by allowing the viewers to “fly” through the grid using a joystick and look at its various fissures and variables from above, below, sides, and all angles, gaining the best-possible understanding of the conditions.

Other major features included heat recovery systems, high-efficiency electrical chillers with variable speed drives, free cooling using plate and frame heat exchangers, high-efficiency boilers, integrated building management and control systems, and daylighting.

The Bow beautifully resolves multiple climate and contextual restraints with a design that creates a striking form, an exceptional workplace environment, and a sustainable development. The building responds to the harsh winter climate by addressing issues of wind load, light access, and thermal comfort. The Bow also creates a public presence in Calgary with its iconic tower and large public level containing a plaza with shops, restaurants, and cafés.

Image courtesy of Nigel Young / Foster + Partners