The Greenbuild International Conference and Expo 2010 was held at McCormick Place West, the largest new-construction facility in the country to be LEED certified. The gathering boasted 25,000 registered attendees as of the middle day of the conference. (EP photo).

By the time the forklifts pulled out and the expo hall opened, more than 1,000 exhibits would welcome visitors. (EP photo).

This year's trade show on green building was the largest Greenbuild Expo ever. (EP photo).

Energy consumption in McCormick Place was monitored and the results were displayed in the Energy Performance Gallery. (EP photo).

Keynote speakers at the opening and closing ceremonies included USGBC CEO Rick Fedrizzi, former Secretary of State Colin Powell (pictured), political pundits Mary Matalin and James Carville, Chicago Mayor Richard Daley, and Paul Hawken, co-author with Amory Lovins of "Natural Capitalism." (EP photo)