I'm buying an old house with 3 apartments. Currently, there's an old FHA system for the first floor apartment, and just gas pipes for the second and third floor apartments. I'd like to convert floors 2 and 3 to central heat. I know putting in ductwork will be very impractical so I was thinking about using forced hot water instead. There is a closet that can be used to run the pipes up from the basement.

Any advice would be appreciated!