How to Insert a Door or Window in a Load-bearing Wall
Inserting a door or window in a load-bearing wall can be a tricky situation, but not an impossible one. The reason why this project is so difficult is due to the potential danger—a load-bearing wall supports the structure, so its absence through accidental destruction could lead to the room or entire house collapsing. However, if you know where to cut into the wall, the project is quite straightforward.
Step 1 - Prep
Because of how crucial load-bearing walls are to the stability of your structure, mistakes must be limited and proper preparation is paramount. This begins with understanding where all the wiring, plumbing, and other fixtures are located throughout the wall. Note if, and how, those fixtures can or will be re-routed to accommodate the addition. It is imperative to know inside and out exactly where you will be cutting, so you must know the approximate size of the door or window itself as well (note that “approximate” implies between two to three inches extra all around the desired area). Mark your area, and place sheeting over it.
Finally, turn off the power to all circuits within the wall.
Work safely and and ensure the power is fully off with a voltage tester or multimeter like the one available here.
Step 2 - Consult an Expert
Before any cutting, you will need an expert. Creating an opening in a load-bearing wall means that the transmitted load down to the floor must be shifted to the sides of the wall. The only way of knowing how much pressure can be allowed is to get an expert to help.
The type of lumber used on the load-bearing wall is an important consideration as well, so check the blueprints, inspect yourself, or call an expert to help out with this. Again, misreading the lumber type can, but not necessarily will, lead to problems, and problems are something to avoid when working with a structure-supporting wall.
Step 3 - Cut the Opening and Shift Support
Use the tip of your saw blade to pierce through the sheeting—this is the starting point. A good tip is to strategically place the rough starting point opening between any wall studs so that a stud is used as part of the framing, cutting time as this eliminates framing for one whole side of the wall. Use the framing square and a pencil to transfer the cut marks to the inside area of the remaining opening, and then continue cutting. If you've determined you have to add temporary support beams or add extra supports to other walls to carry the weight, do that before you make the final cuts.
Next, begin to drill holes at each corner of the opening. These drill marks will help guide your marks on the other side of the wall. Then, with a saw, either hand or miter, continue cutting as needed. If wiring gets in the way, you will need to clamp some wires to reroute them away from the work site.
Step 4 - Frame and Install
After making any and all necessary changes to the opening, including installing framing for the window or door, you're ready to frame and install. Before adding a door jamb, in the case of installing a door, use a level to check the plumb and level of the floor. If the floor is uneven, note that a side of the door jamb will need to be altered so to be completely parallel to the floor. Nail the pieces of your jamb in place with finishing nails and use wood putty to cover the holes. Then, screw the threshold in place, if you need one once it's trimmed to length, and then run a bead of silicone caulk at the edges to seal it properly.
Insert the door in place and use three pairs of wedge shims per side for support and to plumb the jamb. Again note if any changes are needed before securing the hinges to the frame. Then, test the door or window if it is functional, and make final changes as needed.
Insert a Door or Window in a Load-bearing Wall FAQ
Can I put a window in a load-bearing wall?
A load-bearing wall does not have to be a dead end for the DIY projects you have in mind. It is possible to insert a window or a door into a load-bearing wall, but you have to be very careful to do it in a safe way.
Load-bearing walls support the building, so cutting into a load-bearing wall without the proper precaution can compromise the structural integrity and perhaps lead to much more expensive and dangerous problems.
How much does it cost to put a door in a load-bearing wall?
The average cost for framing a window or door in any standard wall of the home is between $120 to $200, which does not include the cost of the window or door itself. Placing an opening in a load-bearing wall, however, can cost up to twice as much because there is extra lumber and labor involved.
The price goes up considerably if you remove the entire wall. This will cost several thousand dollars, on average, depending on how large the wall may be.
How much of a load-bearing wall can you take out?
Load-bearing walls are built to bear the weight of the structure it is supporting, so you must be very careful and safe if you plan to make any modifications to a load-bearing wall. Extra supports and framing can be added to load-bearing walls to make up for new holes for windows and doors.
However, you can remove a load-bearing wall totally if you wish. Extra supports still need to be added to compensate for the weight-bearing structural support you will lose, but it is possible to eliminate the entire wall if that is what you want.
What happens if you remove a load-bearing wall without support?
Load-bearing walls are an integral part of any structure, one of the most integral in fact. If you remove or modify a load-bearing wall without adding the proper supports, you can cause extreme structural damage that can possibly make the entire building collapse.
That is a worst-case scenario of course, but it is still a possibility, which means that you must be extremely careful when it comes to making any modifications to any load-bearing wall or support column that might be holding a building together.
Can you remove a load-bearing wall without an engineer?
Unless permits are required from a local building or housing authority, you can make as many changes to your home as you wish (except in the case where you are a renter). However, it is extremely inadvisable to make any changes to a load-bearing wall without the advice and expertise of an engineer or another knowledgeable professional.
Making changes of any kind to a load-bearing wall without consulting with a professional could compromise the integrity of the entire structure and lead to a collapse that is not just damaging, but potentially even deadly.