What Are the Different Parts of a Window? (What You Need to Know)

The truth is there are all different sorts of windows, and different mechanisms for opening the window, as well as for making it easier to open them, like window balances. But, with that said, many windows are more fundamentally alike than they are different, and as a result, when it comes to window terminology, there are plenty of window parts you should know that you will be able to apply to different types of windows. 

This short guide will help prepare you with some window-lingo. So, what are the major parts of most windows?

The Major Parts of (Most) Windows 

Windows are a critical part of any structure, as they provide for natural light and also in the case of windows that can be opened, for fresh air and ventilation for the spaces within. 

Let’s take a closer look at some of the major parts of most windows

Frame 

The frame, which is commonly made of wood but which can also be made of aluminum, fiberglass, vinyl or even other materials, is the outermost portion of the window and the part that basically provides the structure for the whole assembly. 

The frame supports the whole window and also protects it from the elements, while also serving as the support for all of the other window parts, hence the name. 

Sash

Sash is a term that, while not necessarily misused, is not that well understood. It’s a term we’ve all heard but few of us really understand. 

To keep things as simple as possible, it is the sash, not the frame, that actually holds the glass of the window in place. 

Single and double hung windows are common configurations in which the sash can either be raised or lowered. In the case that the window in question is a sliding window, then it will have either one or two sashes, either one (or both) of which can be moved. 

Casement and awning windows are different types of windows with sashes that don’t slide, but either open inward or outward (usually outward) on hinges. Typically, casement windows hinge on the side and awning windows hinge at the top. Some windows may also be hinged at the bottom, which configuration is known as a hopper or bottom-hung window.  

Glass 

The glass is the one part of the window that we probably all recognize and can easily identify, but even though we all know what it is, there are a lot of nuances that go into the manufacture, and types of, window glass.

Glass varies not only in chemistry, but in the process of production, and can be either tempered (making it physically resistant to shock and temperature), laminated (made of many different layers), or insulated (which makes it better at saving homeowners on their HVAC expenses). 

Window glass can also be treated with special coatings that reflect glare or light, or made with a low-e coating that also helps improve energy efficiency and reduce glare. 

Panes 

Pane and glass are sometimes confused, but to keep things simple, a pane is a single sheet of glass within the window. Sometimes windows contain one pane, sometimes several. Single pane windows are not as energy efficient as those that contain two or three pane windows (called double and triple pane, respectively). 

Sometimes, the spaces between the panes (which are very narrow) are filled with inert gas, such as argon or krypton, which not only improves insulation but which can also help keep noise intrusion from the outside to a minimum (it can also improve privacy because gas buffers also help prevent noise inside the home from escaping. 

Grille

Window grilles, which are sometimes referred to as panes, are decorative elements that produce the illusion that a pane is subdivided into several different sheets of glass. Often made of wood, they are also sometimes made of metals like aluminum or synthetics like vinyl, and sometimes are configurable or removable to produce the desired effect. 

Window Balances 

A window balance is a mechanism that helps offset the weight of the sash (hence the name) providing extra leverage, making it easier to open or close the window. There are many different types of window balances and window balance replacements. Because the balance contains moving parts, sometimes, these need to be replaced. As a result, we sell a wide variety of window balance replacements here; see the previous link for more information. For more information, please see our previous post on “How to Replace a Tilt Window Channel Balance.” 

Window Weather Stripping 

Window weather stripping is material, often made of a low-density closed cell foam, but also sometimes made of vinyl or aluminum, that helps produce the energy efficiency of a window by increasing its insulation. Window weather stripping helps seal the gaps in a window, preventing drafts and helping to keep heating and cooling costs down. Like inert gas between the panes, weather stripping can also help reduce noise pollution. 

Other Window Parts

In addition to the window parts mentioned already, there are other parts of some windows with which it’s worthwhile to be familiar. 

• Sill: The sill, also known as the windowsill, is the horizontal ledge at the bottom of the window frame. It is also sometimes called a stool. 
• Casing: The window casing is the external portion of the frame of the window, on the outside of the house. It helps seal off the window against the elements. This is not to be confused with a casement, which is a type of window that opens on a hinge, typically outward and horizontally. 
• Jamb: The window jambs are the vertical sides of the frame. 
• Head: The horizontal piece at the top of the window frame. 
• Weep holes: These are openings at the bottom of some window tracks that allow drainage so that the bottom of the frame does not trap and is not  sitting in water.  
• Mullion: Mullions are structural components that connect two or more windows. 

Here for a window balance replacement or some other part? Get in touch with us and we will help you find what you need. Hopefully you found this guide helpful and are now ready to talk window terminology - which helps whenever you need to make a replacement!