Cost not set in stone until long after concrete dries

The dollar figures will change.

For one, the numbers are in 2007 dollars, said Chicago 2016 committee chairman Patrick Ryan.

And when it comes to big construction projects in Chicago, as well as Olympic building plans, the bottom line usually isn't solid until well after the concrete dries.

In the last year alone, the cost of a temporary Olympic stadium in Washington Park has jumped from an original estimate of $300 million to $385.9 million. An aquatic center in Douglas Park that was supposed to cost $78 million is now up to $107 million.

Speaking in Chicago last November, British Olympics Minister Tessa Jowell put the 2012 London Games price tag at about $18.5 billion -- almost three times the cost estimate submitted in 2004.

Ryan said comparing Chicago to London wasn't appropriate because London is undertaking a major urban redevelopment as part of its Games, including scrubbing industrial wastes from land once home to manufacturing.

Chicago and U.S. Olympic officials are confident revenues will cover costs.

"Chicago 2016 is, without question, the most thoroughly prepared bid the United States Olympic Committee has ever taken forward," said USOC spokesman Darryl Seibel.