America's tallest tower to lift the Windy City

Developers behind what would be the nation's tallest building - a twisting, lakefront tower in Chicago - will this week discover whether they have crossed one of two final hurdles before proceeding with their record-breaking plan.

The city's planning board last week endorsed a plan for the 150-storey building, known as the Chicago Spire. This week the plan goes before the city's zoning committee and if that gives the green light, the full council is due to vote next month.

"This is a wonderful project, and everyone is very enthused," Constance Buscemi, a spokeswoman for the city's planning department said.

The 2,000ft tower featuring 1,200 residences, would top the city's 1,451ft Sears Tower and become the tallest building in the US. It would soar above the 1,776ft Freedom Tower that is currently being constructed on the site of the World Trade Centre, which was destroyed in the September 11 attacks.

The Chicago Spire was designed by Santiago Calatrava, the Spanish-born architect known for designing the Milwaukee Art Museum addition and the Athens Olympic sports complex. It is being built by the Irish developer, Shelbourne Development.

Shelbourne executives have declined to say how much the development will cost. Estimates by local media have placed it at around $1bn (£500m) though some have suggested it could be as much as $2bn. Currently, the tallest building in the world is the Taipei 101 tower in Taiwan, which measures 1,671 ft and has 101 floors. A tower in Dubai now under construction is expected to reach to 2,300ft and have more than 160 floors.

Garrett Kelleher, chairman of Shelbourne, has said he intends to market the tower's residences internationally with help from the British estate agents Savills and that he expects interest from potential buyers in London, St Petersburg and Madrid.

"I have absolutely no doubt this project is going to sell out," Mr Kelleher told city officials last week.

The developer has said he will contribute 30 per cent of the project's cost while the Dublin-based Anglo-Irish Bank is to provide the remaining 70 per cent.