That included using Fire caulking or fire foam to seal off any air ways from the 1st floor to the second.   

So I've been thinking of joining the Air Force for 4 years, during those 4 years I would buy 3-4 unit properties which later after the 4 years I can get into Commericial real estate by doing a 1031 exchange or getting loans from private investors so that I can buy bigger multi-family properties.

In Indianapolis C to B class neighborhoods I have rarely seen insulation upgraded on rentals especially doubles that have never been owner-occupied.  4th air gaps,  poorly fitting windows, and doors can be easily corrected with proper caulk and weatherstripping (usually).

Air Bnb and short term rental properties were very popular at the time.

Pertaining to air rights and laws we do not develop in this nature so not sure I can be any help here.

Even air bnb only books 40-60% but that's looking like the best option right now.

It makes it easier when you put things into sites like Air BnB and whatnot.

I've been using second nature for a while but it's been terrible. have a lot of problems with getting damaged air filters

Their a/c starting leaking and has missing ductwork, and is blowing air in random places.

I love that you’re already narrowing down specific zip codes and doing your due diligence.I’ve heard good things about 73170 and 73135, especially with the proximity to Tinker Air Force Base, which tends to attract stable tenants.