Bow Tower. Calgary, Bernard Spragg Photo

Stretching across two city blocks, The Bow is a 58-story tower in Calgary, Alberta. This enormous project holds the record for being the tallest building in Calgary, and for having the largest continuous foundation concrete pour in Canadian history...The Bow used 43,000 tons of structural steel and 83,000 m2 (900,000 ft2) of glass. The concrete pour took place over the course of three shifts, involved 500 people, and simultaneously required between 75 and 95 concrete trucks pouring continuously...Through careful building orientation, the tower is able to harness the power of the sun to heat and cool the structure. Its signature “bow” shape vastly reduces wind resistance, increases exposure to sunlight, and allows for more windows to be incorporated into its design.