All jokes aside, it costs more to convert something than to start from a bare patch of ground.* You probably would have to demolish the buildings, rip up the p

All jokes aside, it costs more to convert something than to start from a bare patch of ground.* You probably would have to demolish the buildings, rip up the parking lots, and then go from there. First to subdivide the land, if you want to sell off individual houses or small blocks of apartments. Or else use the whole parcel of land and put a larger set of related apartment buildings on it. * I once looked at the estimates of converting a smallish building into one for a different use. When the estimates came in, the cost of converting that existing building was about 15% more than starting from bare ground. And it would have taken a lot longer.