It swings outward and provides maximum natural light
Casement windows hinge open to the left or right via a crank.
They’re often more energy-efficient than single- or double-hung windows.
Casement windows are excellent at improving ventilation in a home.
Styles include single-frame, double-frame, or push-out.
Chances are you’ve seen dozens of casement windows, but you might now know they have a special name. Or maybe you’ve heard the name before and were stumped, asking, “What is a casement window?” Traditional windows usually include sashes that slide up and down inside tracks, but casement windows have a sash that hinges open, adding to the security and visual appeal in your home and also providing maximum ventilation and natural light.
Casement windows have a moveable sash that is hinged on the left or right side to allow it to pivot open. You operate older casement windows by pushing and pulling the sash open and closed, but modern casement windows have a cranking mechanism to make operation smoother.
You might see standalone casement windows, but they’re more commonly used as the two side windows on a bay window, or next to other casement windows or picture windows to introduce more natural light into the living space.
Casement windows work differently than traditional windows. 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, usually using a handheld crank. When you unlock the window and turn the crank, a set of piano hinges extend to push the window outward and swing it open.
Casement windows (and their fancy European cousin, the French casement window) all have the same handful of components.
The sash is the part of your window that surrounds and holds the glass pane in place, much like a frame holds a picture or a painting. The sash in a casement window is considered a moveable sash, as it’s the part that pivots to open and close the window.
Sometimes called the locking cam or the cam lock, you can find this component on the side, top, or bottom of the sash. The lock and cam are responsible for locking your casement windows when they engage with the keeper. When the window is closed, you can engage the lock and cam by pushing the lever to the other side.
The locking mechanism pulls the sash fully closed, which compresses the weatherstripping around the sash. This is a key reason why casement windows are more energy-efficient than any other window with a moveable sash.
This is the small mechanism within the sash that houses the lock and cam. On standard casement windows, the keeper is embedded in the window frame. On French casement windows, you might find the keeper embedded in the side of one of the secondary sashes.
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 because the two sides of the hinge are installed so that they butt up against each other.
They are typically located on the top and bottom of your casement windows so that they don’t obstruct the view through your window when the sash is open.
The crank is the mechanism that extends or retracts the piano hinges when you turn the handle. The crank might be stationary, or it can fold in depending on the model of the casement window you decide to buy.
If you’re considering installing casement windows in your home, there are some benefits and drawbacks you should consider before you call your local window company.
Casement windows come with many upsides, which make them one of the most popular types of windows.
The sash of every casement window is moveable, but the sash moves differently than it would in a single-hung or double-hung window. Instead of sliding into place, the sash pivots inwards and compresses the weatherstripping around the sash against the frame. This gives you a tremendously powerful seal.
This seal makes casement windows a good choice for energy efficiency in your home, as it blocks airflow between your home’s interior and the outside better than the uncompressed weatherstripping in a sliding window sash.
One of the primary benefits of windows that open is the ventilation and fresh air they can provide. You can let hot air out or cool air in to condition your home naturally and maintain a more comfortable temperature without calling on heating and cooling equipment.
Casement windows provide the best ventilation of any window style because the entire wall opening can open up to the outside. In something like a sliding window or a double-hung window, you’ll always have at least one moveable sash blocking airflow, but that’s not the case with casement windows, as the entire sash opens outwards.
Unlike sash windows that require the leverage of two hands to open and close, casement windows can easily be opened with just one hand. This makes them a good window choice for tight spots where it’s just too awkward to have a sash window, like in a living room or kitchen where couches or countertops could get in the way and keep you from getting the leverage you need to open the sash.
Casement windows open wide, which might, at first, make them seem fair game to intruders. But they are often touted as among the most secure types of windows. That’s because it’s more difficult for an intruder to reach through a broken glass pane to access the crank than it is to open a lock to slide up a sash window. For added security, you might consider removing the crank handle—they twist or pop on and off quite easily—and placing it elsewhere to ensure that the casement window can only be opened from the inside.
Of course, casement windows aren’t without their drawbacks, too, so you’ll want to consider the following before committing.
Casement windows require more complicated opening mechanisms than windows with sliding or push-to-open sashes, so they tend to be more expensive than other styles. On the higher end, casement windows cost as much as $1,000 per window, whereas you might pay just $650 for a double-hung window or $800 for a sliding window.
The interior of casement windows are easier to clean than most other types because you don’t have muntins—also called window grids—or top or bottom rails on sashes to clean around. However, cleaning the exterior of casement windows requires a little more time and effort.
On a double-hung window, for example, you can tilt the sashes in to clean the outside. On casement windows, you can’t reach around to the outside of the window from inside your home, so you’ll need to head outside to finish cleaning them. If your casement windows are on the second story, exterior cleaning will also require the use of a ladder, complicating the process even more.
If you live in an area with nightmare-worthy insects, casement windows without screens will leave the largest opening for pests to come inside, as nothing blocks the opening when the window is open. Screens will add to your installation cost, which is already higher for casement windows than for many other types..
Unlike sash windows that open or close within the window frame, casement windows open outward from the home, taking up exterior space.
People with large yards might not have to worry about children playing near open casement windows, but those with smaller yards or homes closely situated to their neighbors might find it awkward or even dangerous to open a casement window. And if you have casement windows looking out over an outdoor entertainment space, you might be a little more restricted in where you put outdoor furniture if you plan to have the windows open while you’re outside.
There are three major types of casement windows: single-frame, double-frame/French, and push-out.
This is the most basic style of casement windows, and therefore the most affordable. Each single frame is attached by a hinge, allowing you to crank open the window to the left or the right. The sashes usually open outward, but in-swing casement windows, as the name implies, open inward.
Double casement windows have two windows that swing outward—much like French doors—to either side to open, then meet at the center when they close. The hinges permit each side of the window to open at a wide 90-degree angle.
For those that don’t have a center rail dividing the two frames, double casement windows provide a completely unblocked view of and access to the outside. The cost per window and installation for French casement windows is higher than those of a single-frame window, and these are less common.
Rather than using a crank, this type of window doesn’t have an opening mechanism. When you unlock the window, you can push it open. Some push-out casement windows can lock in place while open to provide security and ventilation.
This tends to be the most affordable type of casement window to install, as the manufacturer doesn’t need to include the complicated crank mechanism that traditional casement windows have.
Casement windows can be great additions to just about any home, but they’re particularly beneficial if you live in an extreme climate, or you live somewhere with an enjoyable view.
In extreme climates, casement windows provide better efficiency and insulation than any other window that opens, and they have the benefit of providing ventilation, which picture windows—the most efficient of all window types—don’t, as they aren’t operable.
Casement windows are also excellent options if you live near a lake, a beach, mountains, or some other nice view. The sashes don’t have top or bottom rails that obstruct your view like they would with a single-hung, double-hung, or sliding window, so that view remains yours to enjoy fully.
Considering where in your home you’re thinking of installing casement windows is another important consideration. They make great window styles for living rooms, kitchens, and dining rooms, especially if you’re placing them behind furniture or countertops.
Casement windows are about as easy to replace as any other style, and the process is more or less the same.
However, whether you’re looking to install new casement windows or swap out a set of old ones, you should trust the job of installing replacement windows to a window company near you. Windows are heavy and bulky, making them dangerous to handle, and they’re the first line of defense against the elements, so mistakes during installation can lead to leaks and resulting water damage, as well as decreased home efficiency.
It’s always best to hire a window contractor to get the installation done correctly the first time around.
Barbara Bellesi Zito contributed to this piece.
The average lifespan for a casement window is around 20 years, but some higher-end casement windows with more durable frame materials can last up to around 40 years before you need to replace them. You’ll need to carry out routine maintenance and window cleaning—and, on occasion, casement window restoration—to extend the lifespan of your casement windows. But they tend to wear more slowly than windows with sliding sashes because the weatherstripping sees minimal friction.
Casement windows can either be left or right opening, and every window manufacturer makes both so that you can choose which works best for your space. In many cases, you’ll want one left-opening and one right-opening casement window to sit on either side of a picture window or to act as the side panels in a bay window. Just remember that the direction is described from the curb. An FCL (from the curb left) hinges out to the left if you’re looking at the exterior of your home, and an FCR (from the curb right) hinges out to the right.
Yes, you can absolutely put a screen on a casement window, and most casement windows come with screens. Unlike with a double-hung, single-hung, or sliding window, the screen in a casement window sits on the inside of the window so that the sash can freely open outward. Screens are especially important for casement windows because the large window opening the window provides leaves your home more open to bugs and outside debris than most other types of operable windows.
