I'd suggest looking at some units that have a 9x9 bedroom. 

Have you considered how living in one unit and renting out the others can essentially let you live for free?

Plan is to put 4 + units in the backyard area of an existing duplex.

'A' is relatively newly built with a full amenity package: typically resort level pool, fitness center, dog park, in unit washer and dryer, playgound(s) if mostly family area, maybe covered parking/garages, etc.  

You can pretty much look up recent national appreciation (last decade, this century, etc) and see universally numbers between 3% and 6%.  

I am considering going this route with my unit and would love to hear about others experience.  

What I was thinking to increase cash flow would be to mid term one - two unites.  

This criteria is for 1-4 and 5-8 unit programs.

Like I said, my approach is just about the opposite of everyone on here, but I can tell you that two of my paid for renovated units cash flow more than your 12 units do and I don't worry about making any of our payments and managing 2 units is way easier than 12.

The national banks can't think outside a small, Maru-sized box.Let us know how it goes.