I realize this is highly subjective with a lot of variance, but there must be some average square footage per living unit that one could baseline 'cramped' units against 'spacious' units in an area.Local building code?

I reside in Atlanta, Ga and right now I’m frequently flying back.

Thats a great subject to deal, not seller financing!!!   

I'd just make my offer subject to being vacant prior to closing.  

We live close by and can check on our units frequently (weekly if needed).  

@Jimmy Suszynski This is a very specialized subject.

I would recommend joining a master mind group and meeting on a frequent basis.

I know how to do comps, estimate rehab costs, and give the seller different ways I can buy their house depending on their situation whether its cash, options, lease options, subject to`s, seller financing etc.So, bottom line, if I can get sellers contacting me, I am very confident that, if their is ANY potential to do a deal I will find it, I just need to implement a system. 

I would call your realtor to get a comp analysis as part of your refi process- they may also know of some lenders who work with this kind of situation frequently (especially if you have an investor friendly agent)

Not subjective buzzwords.