Are Casement Windows More Efficient Than Sliding Windows?

Are Casement Windows More Efficient Than Sliding Windows?

There are many choices to consider when you want to install new windows into your home. A couple of these choices include casement windows and sliding windows. They each offer a largely unobstructed views and other benefits. However, if you want to maximize your home's energy efficiency, you may want to know a bit more about each style. In this post, we'll detail some of the differences in the construction and energy efficiency of casement and sliding windows.

Use the links below to skip ahead:

Casement Windows vs. Sliding Windows

Although they can fit into various places and satisfy the necessary functions, there are some considerable differences between a casement window and a sliding window.

Casement windows are often vertical installations. They can also be called crank windows since they typically open and close by winding a crank around one way or another. They do not slide, but instead, they open outward, pushed out from a set of hinges attached to the side of the window frame. Casement windows are the better choice if you are looking for increased ventilation. Although they might not seem to open as far, the way they open outward acts as a sort of semi-funnel to bring passing breezes into your home. Some of them do open entirely, giving you a maximum amount of ventilation.

Sliding windows are relatively self-explanatory in that they are a window in which the sashes slide open from side to side instead of opening outward or vertically. Sliding windows are commonly used on large wide walls to fill the space and provide better framed horizontal views. They typically have two sashes, one fixed and one operable although a three sash configuration with two operable sashes flanking a fixed sash is also popular. The sashes slide along a horizontal plane instead of up and down like a hung window. 

Like casement windows, sliding windows don't have a center horizontal bar so both styles offer clear unobstructed views. The vertical lines on sliding windows go largely unnoticed as they look more like two picture windows set side-by-side.

Are Casement Windows More Energy Efficient Than Sliding Windows?

Casement windows are more energy-efficient than sliding windows. Since a sliding window has to have a flexible seal on the top and bottom runners of the window, it can never seal as tightly as a casement window. There will always be a bit of a gap on the top and bottom sash that allows some air through. A casement window does not have to be flexible, and when it closes and locks in place, the window sash seals tightly against the window frame. 

Should I Get Casement Windows or Sliding Windows?

Since casement windows and sliding windows often fit better in slightly different window portals, part of the decision comes down to what space you have available for the window. Otherwise, think about your priorities while you consider the pros and cons of each.

Pros and Cons of Casement Windows

  • Provides excellent ventilation since the entire window can open
  • Highly energy-efficient since it seals tightly to the sash
  • Provides unobstructed views
  • Easy to clean
  • More difficult to break into
  • May obstruct walkways since it opens outward
  • Crank might need regular maintenance

Pros and Cons of Sliding Windows

  • Easy to clean if they have a tilt-in sash
  • Doesn't require exterior space to open up
  • More budget-friendly open
  • Less maintenance without a crank
  • Can suit the design of a home better as a picture style sliding window
  • Less energy-efficient without a compression seal
  • Reduced ventilation, especially if only half the window opens

Deciding between a casement window and a sliding window primarily comes down to whether you have a space that is oriented more vertically or horizontally. If you are open to changing the space to suit the window, then you can consider either. Casement windows are ultimately more energy-efficient and increase ventilation, but they also do not always suit the aesthetic you hope to achieve. 

The choice for your window will ultimately come down to style and function as long as you are working with specialized window retailer. Window retailers can help you customize the window of your choice to make sure you're getting be most energy-efficient options available. 


Based on your zip code, we do not currently service your area. Please subscribe to receive helpful info on home improvements.


Success! You're now a First Fridays Insider!

Back To Top