Products and ServicesWindowReplacement Window Terminology Explained (Sash, Pane, Energy Efficiency..etc.)

January 3, 2023

Know Replacement Window Terms Before Investing In Your Burlington, MA, Home

Get Informed With The Correct Window Replacement Terminology When Starting Your Home Project

Some Burlington, MA, homeowners are well versed in window replacement language, while some don’t know the first thing about it, and that’s ok. Others may have heard the term but don’t know what it means. At Solid State Construction, we want our customers to be informed and educated before starting their window replacement projects.

When homeowners and contractors are on the same page, the process moves much quicker and smoother. Knowing what to expect and what questions to ask empowers homeowners to confidently take charge of their home projects and helps alleviate the hiccups along the way.

Learn the correct window replacement terms now to avoid miscommunication and to gain control over your home and your replacement windows.


A window sash is the part of a window that fits inside the window frame and holds the glass panes together. The sash can move within the window frame. Depending on the type of window, the sash may be in two parts.

For instance, a double-hung window has an upper and lower sash that moves up and down, while casements may have 1-3+ sashes. Sliding windows can have 2 to 3 sashes, but sometimes only one moves. The sash on a sliding window goes right to left, moving with a crank handle on a casement window.

Why are sashes important for window replacements? Solid, properly-fused, and reinforced sashes prevent your window from shape distortion. If your sash is broken, your window probably will not open or close properly, leading to leaks, airflow, and security issues.


Most people have heard the word “pane” but might not understand exactly what it means. Window panes are the glass sheets that make up a large part of the window. They can be either single, double, or triple-layered and rest within the window frame, letting in light and protecting your home from outside elements.

Depending on the amount of glass pane (single, triple, etc.) used, your home will experience different levels of protection. For instance, if your windows are single-pane glass, you’re more exposed to the outside elements, while triple-pane glass provides optimum protection.

The pane size can vary greatly depending on the style of the window. Window designs and stain-glass windows are typically made up of various size pieces in various shapes, while some windows contain one long sheet of glass.

Energy Efficiency

Energy efficiency is a term thrown around loosely, but many homeowners don’t know how to read or interpret efficiency ratings when replacing their windows. The two most common window ratings that determine energy efficiency are the U-factor and the solar heat gain coefficient (SHGC).

U-factor is the rate at which your window transmits non-solar heat flow or the rate at which heat escapes through your windows. U-factors usually range between 0.20 and 1.20 – the lower the U-factor, the more energy-efficient your window.

SHGC is the opposite of the U-factor, measuring how much heat is absorbed through your window, from the outside in. Technically, it’s the fraction of incident solar radiation admitted through your window and released into your home. Like with the U-factor, typically the lower the number, the more energy efficient your window is.

However, this depends on your location. For example, in the Northeast, you may want a lower SHGC to attract heat in the winter, depending on the direction the window faces.


Frame is a commonly known term, but do you know what it really means when it comes to window replacement? The frame is the structure of the whole window, keeping your sash in place and your home structurally sound.

Window frames are available in several different materials, each with its benefits and shortcomings. Fiberglass window frames are the strongest in frame materials, outperforming their competition many times over. Fiberglass also provides maximum energy efficiency, keeping your home environmentally friendly.

Vinyl, wood, and wood-composite frames are also quite common, each with its own advantages. Vinyl window frames are probably the most used frames in the country, but they are becoming less favorable as better solutions arise.

Insert Replacement

Insert window replacement is removing only the sashes and leaving the old window frame in place, then inserting a whole new window and sashes into the old frame. Insert replacement is cheaper because it uses the existing frame and requires less time and labor.

However, it’s not right for every home, especially if it is older and your window frames need repair. Once an old window is removed, signs of wood rot and mold are evident, forcing more work and money than expected. Though you will typically lose some glass area or daylight opening, if your existing frame is in good shape, insert replacement is more cost-effective and may be right for you.

Full-Frame Replacement

Full-frame replacement involves removing the window and frame all the way down to the wall studs and making any needed repairs to the window opening. Though this process takes more time and money, it provides superior energy efficiency, protection, and comfort.

Full-frame replacements include new casings, stools, aprons, and headers (all parts of the window trim), which are then painted or stained. The process includes better insulation, leak protection, and gives your window a longer life span.

Our Burlington, MA, Window Replacement Company Will Make Your Process Smooth

Since 2006, we’ve been replacing the windows of Burlington, MA, one by one. Over the past sixteen years, we’ve perfected our process at Solid State Construction, ensuring our customers receive unmatched service and outstanding results.

Not only will you get excellent window installation, but you’ll always be met with professionalism, meaning we’re punctual, polite, available, considerate, and so much more. As an award-winning construction company, we hold ourselves to high standards because that’s what our customers deserve.

So, stop hesitating and give us a call today to book a free window replacement consultation!