Structuring a lease to that require rehabs

[Dee Xixi]

In my town, I found a duplex that needs a good amount of rehab. I talked to the seller about a lease to own which he accepts but I am a little bit unsure on how to structure the Lease to own so that if I cant pick up the option I am able to recoup my rehab money. I am thinking on doing the rehab gradually, one side has tenant and the other side is vacant. starts the rehab on the vacant side then move the occupied side afterward. Any ideas on how to structure the deal please.