This may well be asking "how long is a piece of string?" But does anyone have a ballpark incremental cost associated with moving a staircase from the ground to the first floor in a semi detached house, half a meter to the side and front? I am trying to design a side extension room and will not get sufficient space for a small double room there unless I move the current staircase. The entrance hallway is quite large so the staircase can move to occupy part of it. However, im not sure how much this would add to the cost. If it is prohibitively expensive, I will redesign the extension to a smaller room.