Replacement Windows Terminology

Need Replacement Windows?
Here Is The Terminology You Need To Know

A Homeowners Guide
To Window Replacement Terms

Nothing beats new windows when it comes to improving your home’s efficiency and updating the decor. Homeowners will see significant benefits from choosing to replace their old worn-out windows.

However, most homeowners aren’t experts in home improvement. With that in mind, dozens of terms accompany any window replacement that you likely have not heard before – and understanding them will help your project go more smoothly. 

With the overall goal of making the process of replacing windows more manageable, the experts at Jancewicz & Son have crafted this quick replacement window terminology guide with some of the most popular terms you will hear during the window replacement process. 

The Key Replacement Window Terms You Need
To Know Before Getting Started

Air Leakage

Air Leakage, also known as AL, measures the rate at which air passes through your window’s gaps and joints.

Condensation Resistance

This scale from 1 to 100 measures how well the window will resist condensation from the forms on the glass. The higher the number, the better the window resists condensation.


Window panes are glass that sits inside your window frame. The panes are the glass you use to look through and let the natural light into your home. Panes also provide protection from outside elements, keep pests out, and help insulate your home. 


The sash is the movable panel located within a single or double-hung window. These sashes are used to hold one or several panes of glass in place. 

Single Glazing

Single glazing refers to a replacement window using a single pane of glass.

Double Glazing

Similar to single glazing, double glazing is a replacement window that uses two panes of glass. These two panes often contain a thin layer of gas between them. Argon and krypton are the two most common gasses used in double glazing.

Triple Glazing

With the triple glazing in the window replacement process, three different panes of glass are used to create more efficiency. Like double-glazing window treatments, each layer of the triple glazing is separated by a gas. Triple glazing windows are great for cooler climates as they keep the warm air from escaping. 


Jambs support the structural integrity of your windows. They sit inside the frame and tend to be the first part to fail, leading to the need for replacement windows. 


The head is the top part of the window, which is positioned above the window frame. It is more decorative than functional and is available in a variety of styles.


The window sill sits below the frame and is similar to the head in that it is decorative. However, many homeowners like to place objects or books on them.


The frame is the outermost window section and is a vital component of any treatment. The frame can be crafted from various materials, including metal, vinyl, wood, plastic, etc. These material variations also allow for the frames to come in different styles and colors.

Muntin Bars

Muntin Bars make a single pane of glass look like several panes. They are the grids or grates you see overlaid on a more traditional window treatment. Muntin bars can add a classic look to your home and can be used in conjunction with other decorative elements to elevate the appearance. 

Bay Windows

Bay windows are renowned for their beauty. They are made up of at least three or more windows. But the key feature the homeowners love most about bay windows is their angular design which allows the window to extend out from the wall.

If You Are Ready To Replace Your Windows, Contact
The Pros at Jancewicz & Son

Have more questions about selecting the right materials for your roofing installation? Or are you ready to move on to the next step? Then it is time to call on the experts at Jancewicz & Son. Our Customer Service team is standing by to answer questions you might have.

If you are a homeowner looking to replace your windows, call 1-800-281-3585 today!

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