GREEN ROOF ALERT! Lush gardens on top of Chicago’s City Hall!
Posted by ChicagoismynewBlog! on October 20, 2009
This green roof on top of Chicago’s City Hall has got to be the baby of Mayor Daley’s green roofing binge…and I’m glad he made this his first major one because it turned out great. Started in 2000, the City Hall rooftop garden was started as part of the Chicago’s Urban Heat Island Initiative which tests the benefits of green roofs and how they affect air temperature and air quality. The green roof has around 20,000 plants and 100 species which were selected because of their ability to survive on top of an 11 story building in the middle of Chicago.
According to the City of Chicago website: “The City Hall rooftop garden improves air quality, helps conserve energy, reduces stormwater runoff and helps lessen the urban heat island effect. The plants reflect heat, provide shade and help cool the surrounding air through evapotranspiration, which occurs when plants secrete or “transpire” water through pores in their leaves. The water draws heat as it evaporates, cooling the air in the process. Plants also filter the air, which improves air quality by using excess carbon dioxide to produce oxygen.”
The green roof also replaced the traditional black tar roof with green plants, plants that absorb much less heat from the sun than the tar roof would. This keeps the building cooler in summer which means less energy for air conditioning. The roof can also retain 75% of a 1 inch rainfall before stormwater runs off into the sewers.
Unfortunately, the City Hall green roof isn’t open for public tours but if you’re lucky enough to work in neighboring buildings, that’s probably your best bet of seeing the roof. If you want to view the garden from the Department Of Environment’s offices, contact Larry Merritt at (312) 744-5716 for an appointment.
What do you all think of it?