How to Build a Window Cornice

Follow the cut list to size the pieces. For the front and sides, make 45-degree miter cuts where they meet; make 90-degree cuts where the sides will meet the wall. Use corner clamps and wood glue to secure the front to the sides, then tack the corners with a pneumatic nailer and 1½-inch brad nails. To make the French cleat, set your circular-saw blade to 45 degrees and rip a 1x4 in half. Sandwich one half of the cleat between the sides, with the cut edge facing the interior of the frame and pointing down, and secure it with glue and brad nails. Position the top flush at the back and overhanging the front and sides evenly; secure it with glue and brad nails.