The city's planning board has endorsed a proposal for a twisting lakefront tower that would become the nation's tallest building.
With Thursday's approval from the Chicago Plan Commission, the design and site plan for the 2,000-foot Chicago Spire goes to the city zoning committee next week.
"This is a wonderful project, and everyone is very enthused," said Constance Buscemi, spokeswoman for the city's planning department.
The 150-story tower, which would feature 1,200 residences, would unseat Chicago's 1,451-foot Sears Tower as the tallest U.S. building. It would also top New York's 1,776-foot Freedom Tower, under construction at the former World Trade Center site.
If the zoning panel approves the plan, the City Council will consider it May 9. If it is approved, construction would begin this spring, said Thomas Murphy, general counsel to developer Shelbourne Development Ltd.
Shelbourne executives have declined to estimate the building's total development cost. Real estate experts put it at well over $1 billion, the Chicago Tribune and Crain's Chicago Business reported on their Web sites Thursday.
The tallest building in the world is the Taipei 101 tower in Taiwan, which measures 1,671 feet and 101 floors. A tower in Dubai now under construction is expected to rise beyond 2,300 feet and more than 160 floors .