Casement Windows: What to Know Before You Buy

Casement Window

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When shopping for either new-construction or replacement windows for your home, you will encounter several popular window styles: slider, double-hung, single-hung, and fixed. Casement windows often lurk in the background of product catalogs and may escape your attention. But this unique type of window is worth serious consideration and might be a good match for all or part of your home's window replacement project.

What Are Casement Windows?

Casement windows open and close like doors. Casement windows are attached to side-mounted hinges and, with most models, the sash opens and closes as a crank on the home's interior side is rotated. When the sash is fully open, a tensioning device holds the sash firmly in place. When the sash is closed, a latch on the interior of the house pulls the sash tight against the window frame's weatherstripping.

Casement Windows Provide a Fully Open Window

A casement window is the only type of window available on the regular consumer market that fully opens. In essence, you are lifting the sash away, almost off the house, attached only by one thin side. The only other way to have a more fully open window would be to take out the sash entirely.

All other window types only open halfway, at most. Double-hung windows are windows that can have either the top half or bottom half-open. Sliding windows are those that have only one side open. Fixed windows never open.

Casement Windows Catch Side Breezes

If you want to promote air-flow in your house, a casement window can be to your advantage. The open sash on a casement window acts as a flap to funnel breezes into your house. If your home is tightly boxed in by neighbors, the angle of the casement windows may allow you to catch breezes. The sash effectively scoops in air and sends it into your house.

But this can also work against you if prevailing breezes tend to go in the other direction. Breezes that flow over the top of casement sashes will largely not be sent into the home. The casement sash blocks the wind.

Casement Windows Are Better-Designed Than Ever

Casement windows do have a few issues. One long-standing problem is with the potential for failure with casement windows' mechanical operating systems. To counteract this problem, many window manufacturers have improved their opening and closing systems.

Another alternative is simply to dispense with the opening and closing system altogether. Some companies offer push-open casement windows. With this type of window, the only mechanical operation besides the hinges is the tensioning devices that opens the window open.

Casement Windows Offer Clear Views

Do you like the clear, unobstructed views offered by fixed, or picture, windows? Yet you also would like to be able to open the window? A casement window is an ideal hybrid between fixed windows and sliding sash windows.

Casement windows are the only type of window that opens up, yet is capable of displaying a full, unobstructed sheet of glass when closed. Other windows have, at the least, one strip dividing the window. Double-hung and single-hung windows are composed of two sashes, so they have a horizontal strip in the middle. Slider windows have a vertical strip. Fixed windows have no strip, but they do not open.

At the same time, casement windows are stylistically flexible enough that you can opt for dividing strips if you wish. Dual sash casement windows have a functional vertical divider. Or you can choose non-functional muntins: strips of wood, vinyl, metal, or fiberglass that visually divide large sashes into multiple smaller sashes. These false muntins are installed between the double glazing (two panes of glass) or as clip-on accessories.

Casement Windows Are More Secure Than Other Windows

No type of window will entirely stop intruders from breaking into your house. All windows have their weak points and even with the most secure window, the intruder can always break the glass to enter the home.

However, in relation to other types of windows, casement windows are very difficult to break into. With other windows, breaking the glass makes it easy to fully open the window. With double-hung windows, for example, once the glass is broken, the intruder merely has to reach in and turn the latch on top of the lower sash. This allows the intruder to lift the sash and enter the home with no need to deal with the broken glass while entering.

But casement windows (except for push-open windows) can only be opened by turning the window crank. Breaking the glass gives access to the crank, but it is difficult to turn the crank through broken glass. Some homeowners make their casement windows even more secure by removing the crank from the window and keeping it nearby but out of reach.