This story includes tips and techniques to help you prepare to cut into walls.
Remodeling work is more challenging than new construction because often you must cut the opening, reconfigure the framing, install the unit, then patch the walls on the inside and the outside to make it look like the new window or door was always there. The next six pages show some common demolition and patching methods.
Before you begin demolition, be sure to locate any electrical, plumbing, or low-voltage lines running through the section you plan to remove. If you are at all unsure of what you encounter, hire a professional contractor, at least as a consultant.
Electrical lines can usually be rerouted without a great deal of effort, but to do this yourself you must have an understanding of wiring methods. Shut off the power to the circuit before touching the lines.
Plumbing gets messier. Supply pipes can be moved fairly easily, but drain and vent pipes are usually difficult to reroute. The same applies for heating or air-conditioning ducts. If any of these obstacles are present, hire a plumber or find a new place to install the window or door.
If you see an electrical receptacle or light switch in the area, you know there is wiring in the wall. Use a multisensor to detect electrical and plumbing lines. Also look in the basement directly below for plumbing lines and heat vents, which usually travel straight vertically. CAUTION: Even if you are fairly certain that no lines are running through the wall, cut the interior wall carefully and slowly using hand tools, so you can stop if you feel a cable or pipe.
Mark the area you want to cut out. In some cases it makes sense to surgically remove only the area where the wall or door will go; you may be able to hide all the cuts with molding. In other cases you may choose to remove a larger area, and patch it after the installation.
To get a sense of how the installation will look from outside, drill locator holes through the outside wall at each corner. For a house with wood, vinyl, or aluminum siding, use a drill equipped with a long spade bit. For a stucco wall, finish the hole with a masonry bit.