Casement definition, a window sash opening on hinges that are generally attached to the upright side of its frame. Available for Local Pickup Only. If you’re the owner of a Georgian or Victorian home, then you’ll probably find that no other style of window looks quite as good as a sash window. Theresa, from My Fix It Up Life, will show you how in a few simple steps.. Before you start make sure you have the tools you’ll need. See more. Window Sash Components In the past, window sashes were exclusively composed of wood and glass. Do you need to replace your casement window sash? Sash windows are simpler in design than casement windows. Major window companies such as Andersen, Pella, Jeld-Wen, Marvin, and others have window sash replacement programs. Casement windows are often held open using a casement stay. Sash Lock The locking mechanism used on a single- or double-hung window that engages with the sash lock strike to reduce rattling. Modern sash and casement windows both have double-glazed glass to increase the insulation value of the window, but it is around the edges of the frames that the difference between the two lies. Sash replacement kits are usually tied to your brand of window. Modern casement windows have one panel of glass. Pella casement windows are a great option for spots that are difficult to reach, like over the kitchen sink. Sash windows also don’t require any space outside the window to open. This makes for an uninterrupted view of the outside. Replacing the window sash is much easier than you think and most homeowners can take on this project themselves. Find quality casement window hardware online or in store. A window sash is the unified, framed part of the window which holds the sheets of glass in place, along with relevant components such as the mullions or muntins. This type of window is composed of a simple frame that is built to allow easy insertion into window casements. Sash locks and casement fasteners keep windows firmly shut. There are several big differences between sash windows and casement windows. Sash or bar lifts make it easy to let in a clean breeze. Having two sash makes the double hung window the easiest window style to operate and clean. Sash windows offer a traditional style that’s a fantastic match for period properties. Mull over a set of Victorian cast-iron sash lifts from the 1880s or the smooth contour of a modern take, designed to exactly fit your fingertips.