How to Build a Window Cornice
Use poplar boards and primed-pine crown molding to create a custom wood valance
A window cornice adds a strong dose of architectural character to any room and at the same time conceals mounting hardware for drapes or blinds. If your home already has interesting moldings, you can design the cornice to match; if it doesn't, let your imagination be your guide. Or follow our lead to build the one pictured here. It hangs on a French cleat mounted above the window and stands out from the wall enough to allow the curtains to open and close easily. Your cornice should be an inch or two longer than the curtain rod, including the finials, to make it easy to install. It should also be deep enough to clear the finials and the rings by 1 inch.
If you choose to buy a window cornice, there are plenty of wood types and finishes, not to mention architectural styles, to choose from. In either case, you'll never look at your window the same way again.
Overview for How to Build a Window Cornice
1x8 poplar front piece: one at 38 inches from long point to long point
1x8 poplar sides: two at 6⅛ inches
1x4 poplar French cleat: one at 36½ inches
1x10 poplar top piece ripped to 8½ inches: one at 42½ inches
3⅝-inch primed-pine crown molding: Cut to fit.
¾-inch primed pine ogee molding: Cut to fit.
Primed-pine cap molding: Cut to fit.
We made the frame of our cornice (not including the top and moldings) 38 inches wide by 6⅛ inches deep by 7¼ inches tall to cover a 32-inch-wide window with a curtain rod that measures 35 inches from finial to finial and stands a maximum of 5 inches off the wall.