The best way to do this would be to convert your duplex to condo's. You should get a real estate lawyer and title company involved to do so. You'll actually need to set up a condo association to make it legit. This was a popular method about 4 or 5 years ago. Although, lately it's been harder to get financing on half duplex condos. The lenders typically require some money in association reserves. It's definitely worth looking into though.