I'm looking for a house and would like to have a second floor family room. They're hard to find, but many houses I've seen have open space on the 2nd floor above the 1st floor family room, with a railing so you can look down on the room from the upstairs hallway. That is, the family room is two storeys high.
Is it difficult to put in a floor and walls, thus creating a new room out of the open space? I would be looking at hiring contractors, not doing it myself.
It seems to me you'd need a floor, finishing the new ceiling below it, then adding electrical and ductwork inside the existing or new walls.
Is this fairly simple? What would be an approximate cost of having this done for (say) a 15x15 open space?