The property also needs Foundation drip zone installation.

Having a private party as the lender also offers more negotiability, I've found many private parties willing to extend terms with either bulk installment payments or a higher rate of return.

We are doing an installment sale (owner financing) for an otherwise cash buyer. 

Sometimes they will pay you to install for added business.

However, for two people being roommates, some privacy would be better I think...What would be the best way to somehow install doors or some kind of separation?

If you can, go several times, so you can watch it happen from the foundation all the way up.If you live close to a store like Home Depot or Lowe's, sometimes they have free classes on "how to install a ceiling fan" or "how to paint". 

When you recognize depreciation recapture on these types of assets, that depreciation is taxed as "Ordinary" income, therefore is not eligible to be included in an installment sale.   

Check on the property often and install cameras if you think it will be a problem. 

Occam's razor would say the neighborhood power outage was to blame, but I guess they thought we installed TVs, a refrigerator, stove, microwave, outlets and lights everywhere to trick potential guests into thinking we had electricity. 

A 6 ft fence will be installed between the 2 units