It is also usually easiest to leave the exterior sheathing and siding in place while you cut the studs and build the framing. This prevents having to replace siding. However, if you will be replacing the siding anyway, you can cut a large opening in the exterior at the same time you cut the interior opening. If the window has brick molding or a flange, you will need to cut back the siding to accommodate it. If you have a brick wall, hire a professional mason to cut an opening. When framing always work carefully to produce a structure that presents a smooth face for the drywall. Install adjoining pieces perfectly flush with each other. Expect to spend a full day on this project—you’ll need to remove interior drywall and create the frame. Though it looks daunting, this project is fairly simple. We recommend DIYers have experience measuring, marking, and cutting before attempting to frame. Then, examine your studs. In this arrangement an existing wall stud is used as a king stud on one side, and a 2x2 or 2x4 cleat is attached to the stud on the other side to provide a nailing surface for patching the drywall after the window is installed. (This is easier and stronger than trying to cut the drywall down the middle of a stud and then using half a stud’s thickness for the nailing surface.)
