What Is A Sliding Window?

Sliding windows are long rectangles with two sashes. You open the sashes by sliding them horizontally.

While double-hung windows are the norm in most homes, sliding windows are ideal for wide spaces. They are easy to open, can meet egress codes if large enough, and are low-maintenance.

If you’re ready to add sliding windows to your home, here’s what you should know before buying.

What is a Sliding Window?

Sliding window

Even though multiple windows slide open, a sliding or slider window refers to one that opens horizontally.

These windows can be single slider windows or double slider windows. A single sliding window has one sash you can push open, and a double sliding window has two sashes that open.

Where are the Best Places to Put a Sliding Window?

The basement is one of the most common places to put a sliding window. Because these windows are wider than tall, they’re great for filling long, narrow spaces.

But you’re not limited to just the basement. You can get these windows in various sizes to work for the living room, over the kitchen sink, bedroom, or in a small bathroom.

How Much Does a Sliding Window Cost?

The cost of a sliding window depends on size, materials, and brand. You can find small 24” x 24” vinyl sliding windows for as low as $150. Larger sizes exceed $800.

What are the Most Common Sliding Window Sizes?

Sliding windows are among the most versatile when it comes to size. You can find tiny options, great for the bathroom shower, or extra large options that are easy to climb out of in an emergency.

Most manufacturers produce sliding windows in the following widths: 36”, 48”, 60”, 72”, and 84.” The most common heights include 24”, 36”, 48”, and 60.”

Sliding Window: Pros and Cons

Sliding windows are a top pick for wide spaces. But even though they’re secure and easy to open, they have a couple of downsides.


  • Easy to open – Horizontal windows open with a gentle push.
  • Low-maintenance – Sliding windows have fewer moving parts than casement, awning, or hopper windows, making them less likely to need routine maintenance.
  • Energy efficiency – Replacing an old window with a new slider will up the energy efficiency of your home.
  • Work as egress – A sliding window can meet egress codes if large enough.


  • Tracks can get plugged up – The tracks of sliding windows are notorious for collecting dirt, making the window harder to open.
  • Not as secure – Since sliding windows are easy to open and often come with weak locks, they are one of the easier types for burglars to access.

Can You Put an Air Conditioner in a Sliding Window?

You can purchase a vertical window air conditioner (sometimes called a casement style air conditioner) to fit your horizontal sliding windows. With this type of ac unit, installation is easy and works similarly to putting an air conditioner in a double-hung window.

But, you can also put a regular air conditioner in a sliding window, as long as it fits. You will need to secure the ac unit to the window frame and plug the gap atop the unit. Many homeowners choose plywood or plexiglass to block space over the air conditioner.

How Do You Clean a Tilt-In Sliding Window?

Some horizontal sliders have a tilt-in feature that allows you to clean the exterior glass from inside the home. If you’re unsure if your window has this feature, look for latches or buttons near the window locks.

If you find tilt-latches, your window tilts in for easy cleaning. Here’s what to do:

  • Unlock your window and open a sash a couple of inches
  • Press the tilt latches and pull your window outward toward yourself until the window is fully extended
  • Repeat on the other side
  • After your window is clean, put it back in place in the order you opened the sashes

*Depending on your window manufacturer, the tilt-in process may be different. Visit the website of your window brand for specific instructions.

Are Sliding Windows Easy to Break Into?

Sliding windows with only one lock are among the easiest to break into. But, there are things you can do to make these windows more secure.

One of the most effective ways to secure your slider window is to add a dowel rod between the frame and window jamb. Using a simple metal or wood dowel rod will stop the window from sliding open. Plus, since it’s inside, you can move it out of the way whenever you’d like to open the window.

If you’re handy, you can add a sliding window lock or drill screws into the tracks to keep the window from opening. (If your sliding window is egress, don’t drill screws into the tracks.)

Sliding Window vs. Double Hung: Which is Better

Sliding Vs. Double-hung Windows

Sliding and double-hung windows open similarly – both are sliders, but a horizontal sliding window opens to the side, and a double-hung window opens vertically.

The most significant difference between these windows is their orientation. A slider is better if you’re looking for a window that will fit a wide space. If you want a window to fit a tall space, a double-hung window is better.

Frequently Asked Questions (FAQ)FAQ

Is a sliding window cheaper than a double-hung window?

Sliding and double-hung windows are comparable, with sliders being a little more expensive.

Is a sliding window cheaper than a single-hung window?

Slider windows are more expensive than single-hung windows of the same size.

Do sliding windows leak?

With proper installation, a sliding window is not likely to leak. Most sliding windows feature weep holes in the lower track. So, if your sliding window is leaking, clean the tracks and make sure none of the weep holes are clogged.

Can you install a sliding window vertically?

No, you cannot install a horizontal sliding window vertically. It will be susceptible to water and air leaks. Plus, it won’t be safe. Instead, purchase a single or double-hung window.

Can you replace sliding windows with double hung?

Yes, you can replace your sliding window with any style you’d like. Just remember, if not the exact dimensions, you’ll need to expand the window opening to fit a larger option or patch up the space for a smaller window.

Final Thoughts

Slider windows are easy to open, low maintenance, and great for long narrow spaces. The most common places for slider windows are in the basement and over the kitchen sink, but you can use this style of window anywhere.

The most significant disadvantage to a sliding window is that it’s not as secure as most other types. You can up the security by adding a lock or using a dowel rod inside the window. Sliding windows are also slightly more expensive than double or single-hung windows, even for the same sizes.