How to Build a Window Box with Trim
Create a stunning accessory for your home in no time.
A window box brightens a home from the outside and the inside alike, with flowers that can be seen from each side. This one has a crisp, clean look, with squared edges and a painted finish. The simple trim in front adds classic lines.
Use rot-resistant wood such as the heartwood of cedar or pressure-treated lumber. The cleat that attaches to the wall, as well as to the bottom should be treated lumber. The box can be filled directly with soil, or you can have a local sheet-metal shop make a galvanized insert to fit.
Here, the sill is an architectural feature, so the box is installed just below it. Because the sill protrudes 1 in. from the wall, a 1-in. cleat is used for attaching the box. You may choose instead to attach the box even with the top of the sill.