Terms of the Trade: What Are Window Casings?

A window with wood casings looking out onto a snowy winter landscape.

Window casings can be found both on the interior and exterior of windows around the frames. Outside of the house the casings are installed as a sort of weather proofing measure to keep cold air from entering the house from the outside. Inside, window casings have a less utilitarian purpose and are simply decorative as the way moldings and baseboards may be, to give a finished appearance to the look of the window.