The Center is the 6th tallest completed building in Chicago, trailing the Willis Tower, Aon Center, John Hancock Center, and Trump International Hotel and Tower (Chicago) in height.[1] The building's official height measurement increased to from 886 feet (270 m) to 1,007 feet (307 m) when the Council on Tall Buildings and Urban Habitat changed measurement conventions to include ornamental spires during the Willis Tower - Petronas Tower height controversy.[2]