What Is a Casement Window?

Becca Stokes
Written by Becca Stokes
Updated June 9, 2021
Casement Window
© NicolasMcComber / E+ / Getty Images

Casement windows are the accessible, energy-efficient windows you never knew you needed

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Chances are you’ve seen dozens of casement windows and simply didn’t know they had a special name. Traditional windows are usually pulled open and pushed closed using latches on the actual window frame as grips. But one sloppy paint job can be all it takes to seal these windows close and render them difficult—if not almost impossible—to use. 

Casement windows work differently. The key to casement window systems is that they open from the left or right using a set of hinges. They are easy to open and close using a handheld crank, which makes them a smart choice for your home if you put accessibility first. 

When casement windows are installed side-by-side in pairs, they are often referred to as French casement windows, as they give the same open-air feel of French doors.

What Parts Make Up a Casement Window?

Casement windows (and their fancy European cousin, the French casement window) all have the same handful of components.


The sash is the part of the casement window that holds the glass pane in place. Think of it like the frame of a painting.

Lock and Cam

Usually found on the side, top, or bottom of the sash, the lock and cam are the two pieces responsible for locking your casement windows.


This is the small mechanism within the sash that houses your lock and cam.

Piano Hinges

These are the hinges on the side of your casement window that play the pivotal role of opening and closing your windows with ease. You may also hear folks refer to them as butt hinges! They are typically located on the side of your casement windows, but they can also be at the top of the sash. In those cases, they can also be called awning hinges.


This handheld crank can be stationary, or can fold in depending on the model of casement windows you decide to buy. The handle easily cranks open and closed the casement windows.

What Are the Pros and Cons of Casement Windows?

If you’re considering installing casement windows in your home, there are pros and cons you should consider before you call in a professional.


  • Energy efficiency: Because the sash of every casement window is moveable, that means when you lock it closed you get a tremendously powerful seal. This seal makes casement windows a good choice for energy efficiency in your home.

  • Ventilation: If you’re a passionate cook whose stovetop is always bubbling away, casement windows are the ideal choice for you. They make getting air ventilation in your home as easy as turning the hand crank.

  • Easy to clean: Because they fully open, exposing both sides of the entire pane without obstruction, casement windows are a clean-fiend’s dream. Be careful—you may fool the birds if you’re too tidy!


  • Cost: Because casement windows require double-glazing, they can be quite heavy. That means you’ll need to invest in top-of-the-line materials to make sure everything works. On the higher end, casement windows and installation can cost as much as $560 per window.

  • Home security: Casement windows open wide, so it’s imperative that you frequently check that the locking mechanisms are in working order.

  • Screens: If you live in an area with nightmare-worthy insects, you may want to think twice before installing casement windows. That’s because you’d need to have screens installed on the inside of the sash, which can ruin the overall visual effect most people are looking for when they choose casement windows.

Open Casement Window
© Fotosearch / Getty Images

When Should You Consider Installing Casement Windows?

If you live in a place with a beautiful view (or if you’re looking for a good way to ventilate your bathroom), a casement window or a set of French casement windows could be the perfect addition to your home. Anyone looking to reduce their carbon footprint by investing in their home should also evaluate whether casement windows are the right choice for their family.

Are Casement Windows Easy to Replace?

Whether you are looking to install new casement windows or swap out a set of old ones, you should trust the job of window installation to the professionals. And because casement windows are heavier than traditional windows, that goes double! 

But although you’ll have to call in a pro for installation and replacement, casement windows are a cinch to maintain. Because they open so freely, it’s no problem to access both sides of the glass. The open nature of the casement window mechanism also makes it relatively easy to maintain and inspect the hinges.

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