Building residential units above commercial space (in Chicago)

[Josh Jennings]

I own a commercial building, one story, typical Chicago lot (60639), and I pay the crazy taxes (17K year) for it.  I'm new to this RE world, but in doing research, I noticed many of the buildings like mine, with residents above, were paying 6-8k in taxes, a big difference!  In any event, hoping to find someone that has some experience with this.  I don't know how strict the codes or building allowances are in the City of Chicago.  I was hoping to do this soon.  I also have a one-story mix-use building (60623), that I would love to build above!  Also interested in estimating costs into the additions.  Based on the Prop Tax savings alone, it's a no-brainer!