How to Put a Wall & a Window Where the Garage Door Was

Pry off the jamb from the door opening, if there is one, with a hammer and pry bar. De-nail the wood and save it for a future project.

Measure the distance between the inside faces of the studs framing the opening with a tape measure and cut two pieces of two-by-four lumber a length 1/2 inch shorter than the distance you measured. They will form the top and bottom plates of a new wall. Measure the height of the opening and cut two lengths of two-by-four lumber to that figure minus 3 inches.

Construct a rectangle on the ground by placing the top and bottom plates parallel and spacing them so that the two side pieces fit perpendicularly between them. Align the outside edges of the side pieces with the ends of the top and bottom plates and drive 3-inch screws through the plates into the sides to hold the rectangle together.

Mark the position the window will take and measure its width. Insert two two-by-four studs into the rectangle extending from the top plate to the bottom at the window position and separate them by the width of the window plus 3 inches. Screw them to the top and bottom plates. Insert a length of 4-inch-by-4-inch lumber between these studs so its bottom edge is the distance from the bottom plate that you want the top of the window to be from the floor. Align this 4-by-4 header with the top plate so that it is parallel and screw it to the studs.

Drop in two studs that fit between the bottom of the header and the top of the bottom plate and screw them to the studs supporting the header. They are the king studs that will support the header when you raise the wall. Finish framing the window opening by dropping in a length of two-by-four lumber between the king studs to support the bottom of the window and screwing it to the king studs.

Add studs at 16-inch intervals on either side of the window to the end of the wall and screw them to the top and bottom plates. Add framing, or cripples, above and below the window, maintaining the same 16-inch spacing between them.

Raise the wall, tap it into position and align it with the existing framing in the opening. Screw it to the existing header and the existing studs on either side of the opening with 3-inch screws.

Staple tar paper to the outside of the new framing. Cut an opening for the window with a utility knife, then add a few staples around the window opening. Screw siding to the new framing with screws long enough to hold it. Use a siding material that is the same as the existing siding on the garage or one that will blend with it.

Nail 1-inch-by-4-inch trim boards around the new wall to cover the joint between it and the existing one. Install the window into the opening and trim around it with the same material you used to trim around the wall itself. Paint the wall and trim, if desired.

Install fiberglass batt insulation into the bays between the framing in the new wall from inside the garage. Cover the wall with the same material that covers the rest of the walls in the garage. Omit this step if the existing walls are uncovered and uninsulated.