To build a window cornice, measure the window to determine cornice length, cut a plywood or particleboard front piece and two side pieces, join the pieces, and wrap them with batting. Attach fabric to the finished cornice before attaching it to the wall above the window.Continue Reading
Measure the window to decide your cornice length, and decide the height, keeping in mind that standard cornices are 12 inches high. Cut a piece of plywood matching this length for the front piece, and cut two 6-inch side pieces. Use L-brackets or wood screws to attach the short pieces at either end of the front piece to form right angles. If you prefer a wood finish, add crown molding and cap molding along the top and bottom edges of the cornice, and paint or stain the finished piece in your desired shade. Otherwise, wrap batting around the cornice, stapling it at the back before repeating the process with your fabric of choice.
To attach the cornice to the wall, situate it at the top of the window to decide where to drill, and make countersink pilot holes into the wall studs. Use these holes to connect a French cleat with 2 1/2-inch wood screws before hanging the cornice over the cleat. Another option is to attach the cornice using more L-brackets.Learn more about Doors, Windows, & Locks