Casement vs. Sliding Windows: Which One Should You Buy?

Replacing your windows is a big decision. Once you’ve set aside a budget for new windows, the next step is to decide what type of windows you want.

A big question that comes up is, “Do I get casement or sliding windows?”

The answer depends on your aesthetic, window size, use, budget, and more.

In this article, we’ll talk about the differences between casement and sliding windows. By the end, you’ll feel good about the decision that you ultimately make.

Casement Vs Sliding Windows: What’s the Difference?

Deciding between casement and sliding windows so many factors of your home. This includes your energy bills, your home’s overall curb appeal, and your window’s function.

The choice will depend on many factors, including:

  • Appearance
  • Function
  • Window Ventilation
  • Energy Efficiency
  • Maintenance
  • Security
  • Cost

Usually, people use casement windows for window openings that are more tall and narrow. Sliding windows are used for window openings that are wide and short. In the end, it’s up to your preferences.

What are Casement Windows?

We keep talking about casement versus sliding windows, but what is a casement window?

Understanding the terminology is important in talking to your local contractors.

A casement window is a window that has a hinge on one side and opens outward away from your home. The hinge is on the left or right side.

They open like a door. You can have a singular window that opens one way. Or you can have two that open opposite directions.

These are also called crank windows because they usually have a crank that you turn to open and close the window.

What are Sliding Windows?

Sliding windows are a common window style, so it helps to know exactly what it is before doing research.

Sliding windows open side to side by sliding one window sash in front of the other. It’s like a regular window, but you turn it onto its side.

Differences Between Casement and Sliding Windows

Let’s discuss the key differences between casement and sliding windows now that we know the basics.


Appearance is important to look at because they can add or substract to your home’s curl appeal.

You also look at your home every day when walking outside or coming back home from work.

When closed, casement and sliding windows look almost identical. You get two sashes with a thicker bar in the middle for sliding windows. With casement windows, there is no center post.

It’s when you open your windows that you can obviously tell whether you have casement or sliding windows.

Casement windows offer a classical look. They look like windows from fairy tales, such as on the top of Rapunzel’s tower.

Each side opens to opposite sides, letting in fresh air and illumination. You get a completely open view of the outside when the windows are open to their max capacity.

Sliding windows do not offer an unosbstructed view of the outside. At least half of the window opening will always be covered by a sash.

You can have a sliding window where only one side slides. You can also have one where both sashes slide, letting air come in on the left and right side.

A casement window makes a modern home look more classical, and a sliding window is more budget-friendly.


How you open a window affects how easy it is to use in certain places in your home.

The functionality of a window involves how it opens and closes. There are big differences in functionality between casement and sliding windows.

Casement windows open via a crank. This means you don’t have to ever touch the window sash to open it.

For sliding windows, you have to manually push one side open. For some, this can be hard work, especially if your windows are older.

Windows by your kitchen sink are difficult to reach. This makes a casement window the better option if you want to open and close this window often.

Having a sliding window here means you have to reach out to the window and use a lot of force to open it.

There are other options of casement windows without cranks. They are called push out casement windows. You just turn a handle and push the window gently to open it.

Omit, casement windows are easier to open and close in areas that are harder to reach than sliding windows.

Window Ventilation

Good ventilation gives you fresh air indoors. Proper window ventilation can reduce the amount of dust, moisture, and smells in your home.

Windows play a major part in ventilation alongside vents. If you have areas that need immediate ventilation, you open your windows.

Casement windows have better ventilation because they can open all the way. There is no overlapping glass.

Sliding windows can only open half of the window’s area. If you get the double sliding windows, there’s still a piece of overlapping area in the middle.

Energy Efficiency

If you’re paying hundreds of dollars per window, you want to know whether they’ll save you money in the long run.

The energy efficiency of a window affects how much air it’ll leak over time. This matters in the hottest and coldest months of the year when you’re running your HVAC more.

If you choose double-pane or triple-pane, the energy efficiency will also go up. There are other factors as well, including Low E coatings and argon gas-fills.

Casement windows have better energy efficiency than sliding windows. Casement windows do not slide horizontally, they seal completely against the window frame.

Sliding windows are meant to move. On the top and bottom, there is a small gap to allow movement. The energy efficiency is not as good.

The biggest difference is that casement windows have a compression seal. Sliding windows do not. Compression seals form a weathertight space between the window sash and frame. It doesn’t allow any air leaks or drafts to go through.


A window can last over 20 years over its entire lifespan. Over that time, many things can wear down and need maintenance.

Which one is easier to maintain? Casement windows or sliding windows?

Casement windows have more operable parts than sliding windows, such as a crank. This crank needs more regular maintenance.

This is something you can DIY at home with regular cleaning and a spray-on lubricant. Silicone-based lubricants are better since they don’t attract dirt and dust over time.

Sliding windows don’t need regular maintenance to slide open and close.

Sliding windows are more difficult to clean. You need to clean from the inside and outside. This can be difficult if your window is on the 2nd story of your home.

Casement WindowSliding Window
MaintenanceCrank needs regular cleaning and lubricant.Minimal maintenance required.
CleaningEasier to clean both sides without risk.More difficult to clean both sides, especially on second floor.


Many burglars try to break into homes by breaking or prying open windows.

When replacing your windows, you want to know that your home will be secure from intruders and bad actors.

Casement windows are better security features because the locks are built into the frame.

These locks are hook-shaped and special. It’s very tough to pry open a casement window from the outside, even with tools like a crowbar.

Casement windows also have compression seals when closed and latched. This prevents any tampering with from the outside.

Sliding windows, on the other hand, are easier to break into. Most sliding windows have one or two locks. These are easy to undo or pry open.

No matter what window you have, it’s smart to add in home security features such as window alarms and sensors.


Cost. One of the biggest factors when it comes to buying replacement windows. Or anything.

Both sliding windows and casement windows can be quite pricy.

Casement windows end up being more expensive by about $100-$200, depending on the size.

Other factors also affect the cost:

Casement windows are more energy-efficient and have better ventilation. They also have a classical look.

Sliding windows are easier to install and have fewer operating parts.

If you’re leaning towards casement windows, keep in mind they are more expensive.

Contact your local contractors for at least 3 estimates before choosing.

Pros and Cons of Casement Windows

More secure than sliding windows because they have multiple locking points and are more difficult to pry open.More expensive.
Better energy-efficiency because they can create a tight seal when closed.More complex to install.
Excellent ventilation because they can be opened wide to let in fresh air.More regular maintenance because of the crank.
Easy to clean because they can be opened all the way.

Pros and Cons of Sliding Windows

Less expensive than casement windows.More dangerous to clean on the second story of home.
Easier to install than casement windows.Less secure due to less locking points and easier to pry open.
Low maintenance and easy to clean.Not as energy-efficient as casement windows because there is no compression seal.
Window ventilation isn’t as good because only half of the area can open.

When To Choose Casement Or Sliding Windows

Casement and sliding windows are both popular window types. We’ve looked at all the different aspects of each type.

Choosing which type of window is right for you is a tough decision. It is important to think about your needs, preferences, and home type.

Casement windows are a good choice for:

  • Homes with high ceilings: Casement windows tend to be used for window spaces that are taller than they are wide. Casement windows are easier to open with the crank.
  • Homes in windy areas: Casement windows are better for windy areas because they are more secure. Casement windows have a compression seal, offering better energy efficiency.
  • Homes in extreme weather: Casement windows have better energy efficiency for when you’re running your heater or air conditioning more.

Sliding windows are a good choice for:

  • Homes on a tight budget: Sliding windows are less expensive than casement windows. Sliding windows are also easier to install.
  • Homes with limited space inside: Sliding windows do not need any swing space to open. This makes them good for narrow spaces such as hallways.
  • Homes with easy access to the outside: Sliding windows are easy to clean and maintain from the inside of the home. If they’re on the 1st floor, they’re easy to clean. They are more difficult to clean on the second floor.

More factors to consider:

  • Energy efficiency: Casement windows are more energy-efficient. This is because casement windows can create a tighter seal when closed.
  • Security: Casement windows are more secure because they have many locking points. They’re also more difficult to pry open.
  • Ventilation: Casement windows can provide better ventilation. The window can open completely, where sliding windows can’t.
  • Maintenance: Sliding windows are low-maintenance and easy to clean. Casement windows need more maintenance for the crank.

If you are unsure between casement and sliding windows, it is a good idea to consult with your local contractors.

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