|Perched on the shore of Lake Michigan, the Chicago Spire's seven-sided corkskrew design will be more than just an audacious architectural whim.The twist-a clockwise shift at each of its 150 floors-will reduce umbrella-busting gusts of wind at street level by directing of wind upward along the channels. Rounded skyscarpers also sway less than rectangular buildings because wind pushes evenly on all sides.
Contractors broke ground on the building in June; at 2,000 feet and with 1,193 condos, it will be the tallest residential building in the world (tall enought to see the curvature of the planet from the top floors!) when it's completed in 2011. And with green touches such as a cooling system that draw water from the Chicago River, cisterns for collecting rainwater for landscaping, and reflective glass that will prevent migratory-bird collisions, the building is aiming to earn "gold" certification from U.S. Green Building Council, an industry benchmark for environmentally friendly construction.
Twist of Genius Wind will wrap around the Spire's circular design so it won't sway, and it's seven twisted chanels will direct most wind upward, instead of down toward pedestrians. thechicago.com
Source: Popular Science Magazine, December 2007