CHICAGO, Ill. — Two Chicago landmarks will go greener thanks to a partnership between the Clinton Climate Initiative and the city.

This month, former President Bill Clinton and Chicago Mayor Richard Daley announced three projects to retrofit the Sears Tower, the Merchandise Mart and privately-owned housing buildings.

The plans were announced at the Greenbuild International Conference and Expo in Chicago, put on by the U.S. Green Building Council.

The Sears Tower, the tallest building in the United States, and the Merchandise Mart, one of the largest commercial buildings in the world, will undergo audits and retrofits to increase energy efficiency and reduce their environmental footprints.

The improvements will be made through the Clinton Climate Initiative's Energy Efficiency Building Retrofit Program, which was launched in May 2007 and is expected to work with 40 cities worldwide to enhance buildings.

The Merchandise Mart has already been recognized for its efforts; this month it was awarded a LEED-Existing Building silver certification by the U.S. Green Building Council.

The Clinton Climate Initiative and Chicago will also work with multi-tenant housing owners to fund energy-saving changes.

Another U.S. tower making improvements is the Phoenix Tower in Houston, Texas. The exterior will be altered to allow new insulation to be installed. Horizontal rows of glass from the all-glass exterior will be removed and, once the insulation is switched, replaced with silver bands.