He indicated that they have begun to change their business model now and they no longer sell a property until it has been permitted.  

Just adding pets alone really helped boost renting. 

I have some concrete pads in the back of some of my homes, and I have added Costco type storage units to rent it out.

We rehabbed the entire property and added an additional bedroom to each of the units.

So I added one of my listings on booking.com and got my first booking coming up this week for 4 nights.

I hadn't even heard of an ad section before your mention of it.

Solar panels may qualify for the 30% federal energy credit, and advertising expenses, like adding your company’s logo, are deductible.However, Section 280A restricts deductions for any dwelling unit used as a residence for more than 14 days annually, even if partially used for business.

@Jennie Berger gave you the whole kit & caboodle on Chicago zoning so I don't have a ton to ad, however, I'd highly encourage you to engage an architect like @Samuel Pavlovcik or @Prashanth Mahakali, both are awesome local Chicago resources.

The law does NOT apply to landlords:With less then 5 rental unitsThat live in one unit of a duplex and rent out the other unitThat rent out rooms in the home they occupySo, landlords can no longer state in their rental ads, "Section 8 not accepted".The reverse is also true, "Section 8 only", cannot be used.We've always recommended screening S8 tenants the same way as cash-paying tenants.Landlords waiving application fees and/or security deposits only for S8 prospects may also be violating Fair Housing.

Tom, Based on what you've provided, if the property was held over one year, you'd be subject to the long term capital gains rates and any depreciation that you took on the property in the past would have to be "recaptured" (Added to your income) at the short term tax rates (but it will not exceed 25%).