We have an 8-unit apartment building that has 4 furnished MTR units in it.

I had to go to zoning and spend thousands to get it legalized.Your situation seems as if it is zoned as a single family home, and it was split into 2 apartments with no building permits.He's selling the property because he has the wrong zoning, and is finding a bank or an investor who over looks the problems that will arise once they close.With the way things are with insurance, I wouldn't be surprised if your insurance company will not insure for two unitsgood luckGino

In the under $400k price point I'd look at Fairfax, Alexandria (not the brick garden buildings, but newer buildings) and Springfield.

It is better for us to move the tenants out whenever we take over a building that has rents that are way under market.

Do this for a year or two and build up more cash, and then do it again. 

On paper build your empire.  

Beyond that, most self storage only being 8 1/2 foot tall or so wide, a 10 x 30 or 10 x 40 storage unit can't handle RV's and boats.Recreation areas/cheaper land:  The way you beat your competition is to build closer to the Recreation areas or on routes to them, from the populations.

is the land already shovel ready ? 

I noticed your link was actually to the previous Chicago Building Code "13B". 

Both are older homes, the 3/3 was renovated in the 80s.2/1 home is prime candidate for a tandem house out back or teardown and convert to Rowhome zoning, (properties were recently rezoned just across the alley tandem homes, ADU already zoned ok) 3/3 is newer, on a double lot, but my thinking is that I could hold these for a while, go through the rezoning process and sell both if/when the neighborhood continues to get hot enough for more density building, possibly work with a contractor friend of mine to get going in this direction, or try to do construction of tandem home behind 2/2 and then adu behind 3/3 home.Are there any resources for spreadsheets or analysis specifically in this realm/that I could show my financiers to calculate the projections on this?