How to Add an Interior Door

While many homeowners have no trouble replacing an existing door, it is often more difficult to add a new door. This task requires cutting an opening into the wall without damaging the wall or surrounding finishes. The opening must be correctly sized to accommodate the new door and allow it to operate as intended. Fortunately, with proper planning and technique almost any homeowner can add an interior door successfully.

Adding an interior door can change the layout and look and your home.
  1. Choose your door. The easiest way to install a new door is to use a pre-hung unit where the door is already attached to the frame.

  2. Check the instructions on your door to determine how large the rough opening size should be. If no dimensions are given, assume that the rough opening should be one inch taller and one inch wider than the door frame.

  3. Mark the locations of the new door on your wall using a pencil and a straight edge. Think carefully about the location before you choose it. You'll want the door to swing freely without hitting anything or impeding traffic through the home. You'll also want to avoid plumbing so add the door in a spot that is not directly above or below a bathtub, sink or shower.

  4. Use a sawzall or utility knife to cut away the drywall on one side of the new opening. Cut only the drywall and avoid cutting too deeply into the wall cavity. Examine the inside of the wall to see if there are plumbing or electrical components in the way.

  5. Cut the drywall on the other side of the wall away along with any studs that are located within the opening using a reciprocating saw.

  6. Add studs on either side of the opening to frame out the door. Use 2x4 or 2x6 lumber to create these studs, and nails them in place alongside existing framing members. Make sure to maintain the required rough opening size plus a one inch clearance all around.

  7. Slide your pre-hung unit into the opening and add a couple of nails to each jamb to hold it in place. Use wooden shims under the legs of the frame or between the frame and the wall studs to level the unit. Confirm that the unit it level before proceeding.

  8. Add screws or nails along each jamb to secure the unit in place. Make sure to add fasteners to any shims that were used. Add trim or casing to cover the joints between the frame and wall. Repair the floor under the opening or add a threshold to cover any gaps.


  • Avoid cutting into bearing walls. Most interior residential walls are safe to cut, but bearing walls are structural elements that cannot be cut without proper reinforcement and safety precautions. Any wall that runs all the wall along the length of the house should be considered a bearing wall unless you are sure it is not.

About the Author

Emily Beach works in the commercial construction industry in Maryland. She received her LEED accreditation from the U.S. Green Building Council in 2008 and is in the process of working towards an Architectural Hardware Consultant certification from the Door and Hardware Institute. She received a bachelor's degree in economics and management from Goucher College in Towson, Maryland.