The planned height of the Chicago Spire was 610 meters.
Designed by Spanish architect-engineer Santiago Calatrava, the Chicago Spire was proposed as a twisting residential skyscraper beside Lake Michigan. Its planned height of 2,000 feet—about 610 meters—would have made it one of the world's tallest buildings and the tallest residential building ever proposed at the time.
The design called for 150 floors and 1,193 condominiums. Each floor was intended to rotate slightly around the central core, producing a full 360-degree twist from base to pinnacle. Calatrava compared the form to a spiral of smoke and a snail shell, while observers often likened it to a drill bit.
Construction began in 2007, but work stopped in 2008 as the global financial crisis undermined the project. The tower was never completed, so 610 meters describes its planned, not actual, height. It is also easy to confuse the Spire with completed Chicago landmarks such as Willis Tower, which reaches 442 meters to its roof and 527 meters to its antenna pinnacle.