With growing population, taking a single family lot and putting it to its highest and best use, based on zoning, is giving more individuals the opportunity to move into the area.That being said, there are still plenty of ares that the middle class can purchase.  

They might have a list you can just look at so you don't have to go through individual records.

It sounds like the Chicago opportunity is to buy a value add opportunity - which will take capital and expertise to make improvements. 

Upon further though I decided to wait to increase rents until I had improved the property more sufficiently.

If it takes you 5 years to recoup the money you put in to that improvement it's probably not worth it.

An improved rental?

It would be a good idea to see how they are covering the building for flood and all other insurance because you are owning a % of the building however each unit owner is responsible for the whole building and that is why Even if you are in the Penthouse you will likely have to pay for the portion of the flood insurance, even if your individual unit is less likely to flood everyone in the community is responsible for the damage (any damage) to the building. 

A C-corp traditionally has been a poor vehicle for rental real estate but now with a lower 21% tax rate, is becoming a better alternative, especially compared to an LLC which can be taxed as high as a 37% individual rate since LLCs are pass-through entities. 

And you possibly over improved the house .  

Fellow Illinois landlords and property managers,A year ago I rented a home to two individuals who met most but not all of my minimum requirements.