Allow them to smoke wherever they can smoke cigarettes.

Think it through ahead of time how you want to deal with pets, smokers, satellite dishes, pest control, small repairs, large repairs, early termination, lawn care, ETC. 

As far as the health affects/ smell/ damage to the property,  it is a different product than cigarette tobacco, and is unlikely to linger or create any damaging issues once the upstairs tenant is removed. 

Right now I would not recommend chicago area at all I’m no professional but as a life time resident of Illinois I can tell you right now is not a good time to be buying property there new taxes are coming out very soon on property, gas , cigarettes and many other things that are going to be having people run even faster the they already are.

The deferred maintenance was significant- 3/4 of the roof needed replaced, the hallways were incredibly dirty, 3 vacant units that needed complete rehab, residents had anything from holes in their ceiling to faucets shut off because they were leaking so badly, landscaping overgrown and/or dead, and the entire building smelled like cigarettes and urine.

The roof was leaking, the entire building smelled like cigarettes and urine, residents' maintenance requests were ignored, 3 units were vacant, and residents weren't always paying rent.

We wore masks because of COVID, and when we went outside could still smell cigarettes/nicotine through the mask.

For example, would it only work on a light smell from an occasional smoker compared to a heavy smoker? 

Driveway or street parking only.2) We don't allow cigarette butts on the lawn or driveway.

They stay 2 months every 4-6 months.Guests abuse guest policy and cause trouble. ie cigarette butts everywhere, other litter like soda cans & packing materials, trash can overflows.Their initial visit with 1 dog has grown to subsequent visits with 2 dogs.