New Homeowner Edition: Windows 101

Between 25 to 30% of your home’s heating and air conditioning costs disappear right out the window—so making your windows as energy efficient as possible can help you save big money this winter.

But even though you look at them each and every day, you’ve probably not given your windows much thought. Do you know what all the parts of your window are—and what they do? Learn the right names for different parts of your window to help you identify and fix problem areas that might be leaking energy and costing you money.

First, determine what kind of window you have: double hung or casement. Double hung windows are the most common type of window. They have two sashes—the part of the window holds the glass panes together and moves up and down. (Single-hung windows are the same idea, but the top sash is stationary and only the bottom sash opens and closes.) Casement windows open to the left or right with a hand crank.

Now, let’s dive into the anatomy of a window:

Glazing: The glass in the window frame. It can be single, double or triple thicknesses with air spaces filled with argon or krypton gas for energy efficiency. The putty that holds the glass in place is called glazing compound.

Sash: The frame that holds the glass in place.

Rail: The horizontal sides of the sash.

Stile: The vertical sides of the sash.

Jamb: The side pieces that run vertically to form the window frame and hold the sash in place.

Weatherstripping: Weatherstripping should run around the jamb, and at the top of both rails.

Balance: The spring-loaded mechanism on single- and double-hung windows that counterbalances the weight of the sash as it opens and closes. (If you have an older home with original windows, the windows may use a weight and pulley balance system instead—look for a cord that runs along the window jamb.)

Muntin: Otherwise known as grids, muntins can be decorative—sometimes they’re sandwiched between the panes glass or they can snap into place outside the glass—or they can actually hold individual panes of glass in place.

Casing: The molding that surrounds the window, covering the space between the window and the wall.

Head: The top of the window casing.

Sill: Also known as the stool, this part of the window casing protrudes from the bottom of the window like a little shelf.

Apron: the piece of wood that runs under the sill.

Operator: The crank handle that opens and closes a casement window.

How to Identify Window Issues?
Windows last a long time, but over the years they will show signs of wear. If you notice condensation between the panes of glass, this means the weathertight seal has failed and the insulating gas has seeped out—and that means your windows are less energy efficient.

Issues with the rails, casing and other parts of the window can also develop over time. Before cold weather hits, it’s a good idea to check the windows in your house to see if they’re letting in drafts or are leaking. Read this article for three simple, inexpensive tests you can do to check for air leaks around your windows.

What Do You Do About Drafty Windows?
If you discover air leaks, the simple solution is to install energy efficient windows—but that’s a huge investment. Fortunately, Frost King has a line of weatherstripping products that can help cut energy leaks from drafty windows and make your home feel more snug. In this video, Frost King’s Beth Scott explains how to block drafts and make your home more energy efficient:

Disclaimer: The information provided in this blog post is for educational and informational purposes only. Homeowners should always consider safety precautions before starting any home improvement project.  While we strive to offer accurate and helpful advice, Frost King does not assume responsibility for any actions taken based on the information provided or for any consequences resulting therefrom.