The weather stripping is generally adhered to the frame so that when the window or door is closed, light and air are unable to leak through the opening. The materials are strategically sized and placed in order to eliminate any gaps that would otherwise be present when your window or door is closed. Weatherstripping is a very simple and relatively low-cost way to improve the energy efficiency of a home by reducing air leaks through doors and operable windows by sealing the movable connections when the door or window is closed, providing better protection against air drafts.