Ten years after Mayor Richard M. Daley ordered a roof garden planted on top of Chicago’s City Hall, the city has 500 green roofs downtown and scattered throughout its neighborhoods.  According to Department of Environment spokesman Larry Merritt, green roofs cover approximately seven million SF, although that represents less than one-tenth of one percent of Chicago’s 500,000 buildings.

City Hall’s roof garden, for example, has more than 100 plant species, including native prairie grasses.  The Willis Tower is now sporting a partial green roof, located on the 90^th floor, that is tied down with steel ropes to protect it against the wind.  One of the city’s few green roofs that is open to the public tops the 555 West Monroe Street building that serves as PepsiCo’s headquarters.  Writing in the Chicago Tribune, Pulitzer Prize-winning architecture critic Blair Kamin describes PepsiCo’s green roof as having “a swath of grass, tables and chairs, and four twirling wind turbines that are handsome enough to be kinetic sculpture.  This green roof isn’t an energy-saving toupee.  It’s integrated into the daily life of the city and the people.”

On the city’s Far North Side, an organic farm tops the Uncommon Ground restaurant at 1401 West Devon.  According to Kamin, the farm is “totally in sync with the restaurant and its embrace of the ‘locavore’ philosophy of locally produced food.”  Another green roof – visible from the CTA’s Red Line – tops an Aldi supermarket at 4450 North Broadway.  Kamin isn’t so impressed by this green roof, noting “It resembles a postage stamp.  Green roofs, it shows, can comply with the law without adding much beauty to the cityscape.”