Chicago City Hall's Green Roof

City Hall wants to send a message to the rest of the Chicago. The message rings out loud and clear: our air quality sucks, and we need to do something about it. In a city notorious for government waste, crumbling public transportation and an almost nonexistent recycling program, City Hall installed a green roof in 2001. Yes, a green roof. What does it all mean?

Why does Chicago's City Hall have a green roof?

The Chicago City Hall building is like most big government office buildings-huge and expensive to maintain. Since the green roof was completed, Chicago's City Hall building is saving about $5,000 a year on heating and cooling costs. Over time, that adds up to a lot of saved taxpayer money in a city known for budget woes.

But didn't it cost a lot of money to build?

Yes. The City Hall's green roof cost $2.5 million. But it was funded by a settlement from ComEd (the local electric company), so it really is saving money.

There are other benefits to having a green roof on top of City Hall. Large cities tend to trap a lot of heat close to the earth, making them hotter than surrounding areas. Green roofs in general help to diffuse this heat. The green roof also naturally traps (and uses) rainwater before it ends up in the overworked sewer system.

Chicago's City Hall is setting a good example for the rest of us. According to MSNBC, more than 250 other Chicago buildings had installed green roofs by 2006.

How big is it?

The green roof covers the entire City Hall building, which is 20,300 square feet to be exact. Or to put it in more understandable terms, it's like raising a block-sized garden eleven stories off the ground. According to the city of Chicago's website, "The garden consists of 20,000 plants of more than 100 species, including shrubs, vines and two trees." To keep the roof from collapsing under its own weight, a special lightweight soil was used in the construction.

Can I see the green roof at City Hall?

Yes and no. As a member of the general public, you can't just take an elevator up there and look around. Like most green roofs, it wasn't really designed as a place you can walk around, but as a functional roof covering.

You can see it from any of the nearby office buildings that overlook City Hall's green roof, or you can make an appointment to see it from the Department of the Environment's office. Call Larry Merritt at (312) 744-5716 to schedule.

Resources:

City of Chicago: http://egov.cityofchicago.org/city/webportal/portalDeptCategoryAction.do?deptCategoryOID=-536889314&contentType=COC_EDITORIAL&topChannelName=Dept&entityName=Environment&deptMainCategoryOID=-536887205

Green Roofs: http://www.greenroofs.com/projects/pview.php?id=21

MSNBC: http://www.msnbc.msn.com/id/15223547