Water pipes or electrical cables can often be moved without a great deal of difficulty, but check with a plumber or electrician first. Drainpipes and heating or air-conditioning ducts are more challenging to move; if one is in the way, you may have to relocate the doorway. Before building exterior door framing, you should also determine what sort of stairway you’ll need outside. By looking at an existing door’s bottom relative to the house’s siding, you can tell how high the stairway will need to be. Then, consult the door manufacturer’s instructions for the correct width and height of the rough opening you’ll frame. The method shown here minimizes drywall work. Project tip: Most homes have platform framing, with studs that span between a bottom and top plate. Some older homes have balloon framing, in which the studs travel up through the floor and the ceiling with no plates. If you have balloon framing, you’ll need to cut the studs to the height of the floor joists (that is, the bottom of the subflooring). Also, cut and install short cripple studs for each side and cut a piece of subflooring to fit.
