Window Anatomy: The Many Parts of a Window

parts of a windowWhen you look at your windows what do you see? A window is more than a piece of glass. There are many parts of a window, some that differ from window type to window type. That’s why we are going over the anatomy of a window and figuring out what makes them up.

Parts of a Window Frame

The frame is what holds the window in place. This keeps the window secure in the wall as well as adding a bit of style. There are several parts of the frame: The head is top horizontal part of the frame. The vertical boards between the head and the sill are the jambs. The sill is the bottom horizontal part of the frame. sill of a window The horizontal board on the inside of the window against the sash is the stool. The grilles, or also known as muntin, these are the bars on the sashes that break the glass into smaller panes visually. grilles on a window

Sashes: What Is a Sash?

The sash refers to the part of the window that is held within the frame. There are two types of sashes: operating and fixed. Operating sashes are movable while fixed sashes stay in place. Different windows have different style sashes which effects which parts go into them.

Different Styles Have Different Parts of a Window

As mentioned above, not all Windows have the same anatomy. Each window has different parts.

Double Hung Windows

There are two sashes: upper and lower sashes. These are both operating sashes that make up the double hung window. The stile are the jambs of the sash. They are the main vertical parts of the sash frame The rail: they fit between vertical components of a window. These are how the windows move The device that locks the sashes is know as a strike. They are typically found on the top of the lower sash.

Casement Windows

Many windows have different locations for there hinges. On a casement window, they are usually found on the jambs of the side that doesn’t open. The hinge tracks are on the base of the hinge that keeps it attached to the window and frame. Gives the window its limited mobility and keeps it from falling off. crank for a windowThe crank is the device that the owner manually moves in order to open the window. It can be found on the sill, bottom of the trim or bottom of the grills. It works directly with the hinges.

Awning Windows

Operator arms are the found on the bottom of the sash and allows the window to open outwards. operator arm The hinges on an awning window are in a unique spot: the head of the frame. This causes the window to open from the bottom

 Sliding Windows

The rails of a sliding window are found on the head and the sill of the window. This gives the operating sash the ability to slide on the track. The handle found on the operating sash that allows the owner to pull the window open is known as the sash pull. Locks are typically located on the operating sash, opposite side of the sash pull.

Hopper Windows

On hopper windows, the hinges are found on the sill and bottom of the window that allow it to open from the top. The operating arms are found in the center of the jambs. This keeps the window from opening too far.

Even Glass has Parts

In the past we have discussed the safety features of window. Did you know that some types of glass have more parts than just the single pane? We’ll go into greater detail and explain the different parts of the glass.


Spacers are found on the top and bottom of the window’s frame. They are used to hold together two or three panes of glass for better insulation.

Double/Triple Pane Windows and Argon Windows

A pane of glass is a single piece of glass used for a window. Double Pane windows are actually two panes of glass held together with spacers. In between those panes of glass is usually argon gas. Argon gas is added to a window to increase insulation and reduce noise. There is also a triple pane option and argon is found between all three panes.

Low E4 Coating

All objects, including windows, emit heat. The lower the amount of heat emitted, the more insulated the object. Low E4 coated glass emits less heat and improves insulation. The coating is found on the surface of the glass. According to efficient windows, a normal glass window emits 86% heat while a Low E4 pane emits only 4% heat.


We wrote an article about front door hardware, but now its time to talk about window hardware. The owner of the window can add additional parts to a window.

Weather Stripping

Weather stripping is used to seal gaps around your window. This is done to improve the insulation. The weather stripping is applied between the jambs and your home’s trim.

big luxerious curtainsCurtains and Blinds

Curtains and Blinds add privacy to your home as well as protect your furniture and floors from UV rays. The curtain rod is installed two inches above the top of the window frame.  If you were interested in curtains, we wrote an article that will help you measure your windows for curtains.

But Wait, There’s More: Other Parts of a Window


The apron is a horizontal board that is installed beneath the sill of the window. It helps give your window a creative design and modern look.

casement window lockLock

Locks are found in different places with different windows. There are many different styles and types of locks that are available for each window.

There Are Many Parts of a Window

There are several different types of windows and with each type of window, a different set of parts. With each window having different parts, it is important to understand what you are getting before buying. Knowing the parts to your window and what features they add will help decide which window is right for your home.  

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