Chicago's Sustainable Development

Hey guys. I am doing research for a class at Texas A&M on Chicago. One aspect of my research is 'Sustainable Development'. I have only been to Chicago once(really great expirence) so I am not that familiar with the city. I was wondering if I could get some names of developments, old or new, that are 'sustainable' or that you just really like. I'm trying to show off your great city to all these Texas country people so feel free to brag and give me great stuff!! Thanks! -txaggie>