DENVER -- The Environmental Protection Agency (EPA) officially opened a new regional office building in downtown Denver, designed to achieve the second-highest ranking from the Leadership in Energy and Environmental Design (LEED) system, which is administered by the U.S. Green Building Council, according to Business Week.

The $90 million, nine-story, 292,000-square-foot building is expected to use 40% less energy than similar-sized buildings. Wind-power purchases will offset 100% of the building's electricity, and a rooftop garden will help absorb heat and filter rainwater. The building was developed and leased to the agency by Minneapolis-based Opus Northwest LLC, and has energy-efficient equipment, workstations built with sound-absorbing material and insulated glass to filter sunlight and reduce heat.

"At the EPA, we're not just talking the talk, we really are walking the walk by this building," said Stephen Johnson, the agency administrator.