How to Make an Upholstered Window Valance Box

Take three measurements to determine the size of the window valance box. Measure the length of the drapery rod, the length of the draperies and the depth for the box. This is a measurement from the wall to the front where the draperies protrude.

Add 2 inches to the rod length measurement, and cut two pieces of plywood to this length using a hand saw. For example, if the rod length is 48 inches, cut two pieces 50 inches in length. Calculate one-fifth of the length of the draperies, and cut one of these pieces to this width. For example, if the length of your draperies is 50 inches, cut one piece 10 inches wide. This is the front piece. Add 2 inches to the depth measurement, and cut the second piece to this width. For example, if the depth measurement is 8 inches, cut the piece 10 inches wide. This is the top piece.

Measure and cut the two end pieces. The measurements will equal the height of the front piece and the width of the top piece. In our example, each piece will be 10 inches wide and 10 inches long.

Assemble the three-sided box. Run a bead of wood glue along the end of one end piece, and attach it to one end of the front piece using a hammer and 1-inch brads. Repeat the process with the other end piece. Complete the assembly by attaching the top piece in a similar fashion.

Add the length of the front piece and both sides together. In our example, this totals 70 inches. Measure and cut your batting to this size. Spray the front and sides with spray adhesive, and then attach the batting.

Add 4 inches to the batting measurement for the length of your upholstery fabric. Take a measurement from the bottom edge of the front piece, up the front side and over the top to the back edge. Add 4 inches to this measurement for the width of your fabric. In our example, the size of the fabric will be 74 inches long and 24 inches wide. Cut the fabric to size.

Lay the fabric front side down on a flat surface, and center the front of the box on top of the fabric. Pull the fabric over the middle bottom edge of the front piece. Attach the fabric to the back of the box with a staple gun.

Pull the fabric and staple it under the center edge of the top piece. Continue to staple the fabric to the box, alternating between the front and the top piece and working your way to the sides. Repeat the process with the side pieces.

Fold the fabric inside the corners similarly to the way you make hospital corners. Secure the folded fabric to the back of the box with staples.

Attach an L-bracket, using a screwdriver and screws, to the wall just above each end of the window opening at the desired height. Set and center the upholstered valance box on the brackets, and attach it to the L-brackets with screws.