GA basement, can it be rented?

[Delsater Z.]

Hello good people of GA! I need your advice

Im considering a Duplex near Decatur GA (Atlanta area) with a partially finished basement as part of of the deal; supposedly could be finished and rented as a 3rd unit. However, the sellers don't have a permit for it, nor water/electrical meters etc.

The house was built in the 50's, Zoning is R-75, and Tax document reads "Improvement Type: 06-DUPLEX 2 FAMILY RESIDENTIAL"

Its built on a slope with the 2 units on the upper part and a separate basement below, with its own entrance and windows on all 3 sides.

The owner has already done the framing (each room has a window) as well as electrical wiring, plumbing, AC and ducting.

I would have to continue finishing myself as well as get permits, water/electrical meters etc..

Does this sound legit?

How possible is it to get a variance (or improvement) and make it legit as a 3rd rentable unit?

I'd really appreciate your insight!

Z