The new 'green' building will have state of the art energy-efficient features. Solar panels and reflective roofs will help reduce energy costs and greenhouse gas emissions.
Mayor Daley said such buildings could save $150 million in energy costs.
"This project will stand not only in the history of Chicago, but I believe in this country and the world. People come here and look at dealing with the design and with the construction and, of course, all the environmental issues that go within this wonderful building," he said.
Mayor Daley also said Chicago will waive fees for developers who build environmentally friendly high-rises in the city.
