How to Frame a Basement Window

Framing a basement window is an important factor in building a basement wall where there's a window. Buidling a interior wall next to an exterior wall is a good way to insulate your basement from outside tempereatures. If you decide to insulate your basement that has a window, and if you choose to insulate with a new interior wall, you will need to frame the window. If you lack the experience to do this project but would like to give it a try, you will find this project to be easier and less time consuming if you have a few instructions such as the steps below.

Step 1 – Measure Dimensions for Your New Walls

To estimate the lumber you'll need for your new wall and window frame, measure the length of the exterior basement wall near which you'll be building your new framed wall and window. Assuming your walls will be the standard 8', multiply the number of linear feet of your exterior wall by 2, then divide that total by 8. This will give you the number of 8' pieces of 2x4s you'll need for your top and bottom plates (the term for the horizontal parts of the wall). Then, divide this same total by 8 to get the number of 8' studs you will need. Add 2 more 8' pieces of the 2X4s lumber for your window frame and this should tell you how much lumber you'll need.

Step 2 – Mark Stud Locations on the Plates

Lay your top and bottom plates side by side with the ends even. Using your tape measure, place a mark every 16" on both plates.

Step 3 – Attach Studs to the Bottom Plate

Place a wall stud against the bottom plate where you have marked it. Attach the stud to the plate by driving 16 penny nails or 2" screws through the plate and into the stud. Do the same with the far end stud. When both studs are attached you should have an 8'X8' square. Attach the other studs to the top and bottom plates as you did with the end pieces.

Step 4 – Measure, Cut and Install the Window Frame

Measure the distance from each wall to the edge of the window, measure the width and height of the window, then mark the wall studs where this window frame will be located. With your saw, cut a length out of each stud that matches the height of the window frame, then attach a top and bottom plate so that you create a square in the studs. This square, with a 2x4 piece on the top, bottom, and both sides, will be the window frame into which you will install a window.

Step 5 – Attach the Wall Frame to the Floor

Life the wall frame into place, lining up the window frame with the window in the concrete wall. When your frame is perfectly parallel with the exterior wall begin attaching the bottom plate to the floor, using a stud gun to drive concrete nails through the bottom plate and into the concrete floor.