Carriage House / ADU Atlanta, Ga

[Paul C.]

Hi I recently purchased a .6 acre lot in Cobb County Georgia that has a duplex sitting on it. At first I was simply going to rehab duplex and rent, but I have seen this idea that you can actually add an ADU to land zoned as multifamily that I am thinking about pursuing. My question is, what should i expect to pay either price per sq foot wise or total to add a carriage house with like a 2 door garage and a 2 bed 1 bath on top(Quality wise I would want somewhere in the middle, not crazy expensive, but not super cheap either). I know there are a lot of hoops/permitting issues that I will need to address, but wanted to see if it makes any sense financially before I track all that down. Lower or higher than $100k to build entire thing?

Thanks,