How to Custom Build your Own Window Cornice

A home with window treatments.
What You'll Need
Piece of 1x6 wood at least 6” longer than the width of your window
2 pieces of 1x6 – approximately 6” long
8 2” ‘L’ brackets
Tape measure
Power saw
Screws and screw driver
Power drill
Wood glue
Cotton batting
Material to cover the cornice and complement your room’s decor

Adding a custom made window treatment made with a material chosen to enhance your room’s décor may sound difficult, but in reality, it’s one of the easiest and inexpensive home projects you can take on. There are no special tools required and the materials you need are readily available at home and department stores. Best of all, the project can be done in just a few hours so your room can be updated in an afternoon. Here’s how to build your own custom window cornice.

Step 1 - Measure the Window

Start by measuring the width of your window. You want the cornice to be at least 6 inches longer than the width of your window, however, there’s no rule that says you can’t make it longer if you want your window to appear wider.

Step 2 - Cut

Measure and cut a 1x6 piece. While you’re cutting, also cut two other pieces of wood at least 5¼ inches long for the ends of your cornice. You want your cornice to protrude at least 6 inches and a piece of 1 inch wood is actually only ¾ inches thick. You could make the end pieces longer to accommodate a double curtain rod, but you need at least 6 inches minimum clearance.

Step 3 - Place Wooden Ends

Lay the long front piece down on a flat surface, then place the wooden end pieces on top, flush at each end. Now, put two ‘L’ brackets the inside at each end, joining the front and end/side pieces. Mark the screw hole locations of the ‘L’ brackets, move the brackets out of the way and pre-drill small pilot holes.

Step 4 - Use Glue

Next, run a bead of glue on the edge of the end pieces where they meet the front and install them by screwing the ‘L’ brackets in place.

Step 5 - Mount the Brackets

Prepare your cornice for mounting by installing two ‘L’ brackets on the inside of each end piece where it will attach to the wall. Be sure to pre-drill pilot holes to prevent the wood from splitting. Having two ‘L’ brackets on each end will ensure your new cornice won’t sag away from the wall.

Step 6 - Cover the Frame

Start covering your cornice frame by cutting your material the length of your front and side/end pieces and about 10” wide. Lay your material onto a clean work surface with the good side facing down (this will be the side on view when the cornice is installed on your wall). Put some cotton-batting cut to fit on top of your material and finish by placing your wooden cornice frame on top of that.

Step 7 - Wrap the Material

Starting in the middle of the front, wrap one side of the material around the wooden frame and staple it in place. Continue wrapping and stapling, working from the middle to the ends along one side.

Now, go back to the middle and tightly wrap the loose side of the material around your cornice, again starting in the middle and stapling it firmly in place as you work along the length.

That’s it. Your new, custom made cornice is ready to be installed over your window.