Window Glass Types: Glazed Windows

What are Glazed Windows?

Glazed windows refer to the panes of glass that are used inside of a window frame. There are single, double or triple panes for windows. Often, the terms window panes and window glazing are used interchangeably by contractors. So you may hear your contractor recommending you double glazing or double-paned windows for homes.

To achieve double glazing, the panes are aligned parallel to each other and glazed or sealed using a putty with space in between. The putty helps placing the glass panes on the window frame and hold the structure together. 

The space between the two glass panes can be either air or gas filled. The two panes of glass and the gas inside form an insulating barrier, called an insulated gas unit (IGU), that helps keep heat and cold from passing through. Thus, helps to keep the temperature inside your homes comfortable in both warm and cold climates.

Types of Glazed Windows

Choosing the right windows for your home not only contributes to its curb appeal, but can also go a long way toward keeping it cool in the summer and warm in the winter. As you consider your choices, you will find options for window glazing to increase your home’s energy efficiency. In order to find the right product, it is important to understand how window glazing can benefit your home.

Single Glazed Windows

Also called single pane windows, these windows only have one sheet of glass inside the frame. If you have an older home, chances are you have single glazed windows because those were the only types widely available when these houses were built. However, if you are thinking about installing new windows, this may not be a great choice for your home. Single glazed windows are considered less energy efficient than other types as they allow hot or cool air to escape from your home, making it difficult for your HVAC system to run at its most effective level.

On the other hand, single pane windows do add to the authentic look of older homes, so some homeowners may choose to continue using them to maintain a certain aesthetic. In addition, single glazed windows are less expensive than other kinds—$50 to $200 per window, and more lightweight so you don’t need heavy-duty frames to support them. They may be a good choice for areas of the home that don’t need to be well-insulated, such as the garage or shed.

Double Glazed Windows

Double glazed windows have two panes of glass that have a space between them. In order to create insulation, argon gas—which is a nontoxic, odorless gas—is used to fill the space between the two panes of glass. As a result, double glazed windows are more energy efficient and they can help reduce any noise in your neighborhood from disrupting the peace in your home.

Despite these benefits, it’s important to keep in mind that double glazed windows are significantly more expensive than single glazed windows at $385 to $850 per window. To get the most out of your investment, you will need to replace all the windows of your home, otherwise you won’t fully reap the benefits of having these types of windows in one area of the house. Also, if you haven’t taken other measures to ensure your home is properly insulated, getting double glazed windows may not help that much. Another factor to consider is the fact that although argon gas is not harmful, it does leak over time, so you need to pay attention to that and at some point, have the windows refilled to maintain them.

Triple Glazed Windows

If you live in an extremely cold climate, triple glazed windows, which are three panes of glass with argon gas in between them, are a good choice. These windows are the most energy efficient variety, but they are also the most expensive—costing $550 to $3,550 per window—and the heaviest. However, the upfront costs that you spend on these types of windows may be offset by the amount you save on energy bills later. In addition, triple glazed windows are the most effective at noise reduction, making your home feel more snug and comfortable as you avoid disruptive sounds from the outside world.

Can I Add Glazing to Existing Windows?

It’s not always cost-effective to replace all the windows in your home, particularly if the frames are still in good shape and are not very old. If you have poorly-insulated single-pane windows, you can add an additional pane of glass to them.

Retrofit double-glazing, usually made out of PVC or acrylic laminate, is applied to your existing single-pane windows to effectively turn them into double-glazed windows. Another method to achieve this is done through an acrylic insert held into place by magnets.

Either way, by retrofitting your windows you can keep the frames you already have, and get some of the benefits of insulated glazing.

When You Should Replace Your Windows Instead of Adding Glazing

There are still situations where a total window replacement makes the most sense. You should start budgeting for replacements if your windows display any of the following:

Windows Fog Easily

The energy efficiency of your windows depends not just on the type of window frame and glass, but also on how expertly the window was joined and installed. If you see condensation or fog on your windows, it’s a sure sign that your manufacturer or installer slacked on the job—and your best bet will be to splurge for some new windows that have a reputation for performing well.

Windows Are Hard to Open or Clean

If the windows become stuck or jammed easily, then they’re not really doing their job, are they? You deserve to have windows that you don’t mind opening—and in some cases, stuck windows could be a fire hazard, so if you avoid opening your windows, it’s time for a replacement set.

Window Frames Are Rotten or Warped

This may seem a little bit obvious, but it is very important. The benefits of double glazing hardly apply to windows with shoddy frames. In fact, unless your frames are in great shape, it’s generally best to go ahead and replace them.

Window Style is Outdated

Homes go through fads just like your wardrobe does, and one of the big functions of windows is to improve your home’s curbside appeal. If you’re unhappy with the look of your windows, it’s better to plan for an eventual replacement than invest in a temporary solution—especially if you think you might put your house back on the market one day.

When You Should Retrofit Windows With Double Glazing

You should only add double glazing if you feel secure that your window frames are in tip-top condition—and you can vouch that they’re of the highest quality and that the installation went off without a hitch. Here’s when retrofitting is appropriate:

You Want Better Energy Performance From Your Windows

While there are many factors that affect window performance, double pane windows have been shown to consistently offer better overall energy savings. Typically, retrofit glazing with laminate doesn’t make quite as drastic a difference, but it does improve energy efficiency.

You Really Like Your Existing Window Frames

It’s hard to toss something you love. Retrofit glazing offers a compromise when you have custom, historical, or one-of-a-kind frames that really can’t be replaced all that easily.

You’re Sure the Window Glass is the Problem

Windows may seem simple—but they’re actually full of joints, and inadequate sealing in those places can have a big effect on your home’s energy profile. Additionally, the seal between the window and the wall and even the caulking on the window itself can cause issues as well.

Before you assume that your single windows are to blame for your energy woes, you may want to, at the very least, inspect and replace the caulking around the window seals.

Find an Experienced Contractor

Finding an experienced contractor for your window installation doesn’t have to be a chore, thanks to Modernize. We frequently speak to homeowners about their home improvement projects, so we understand what you need and can help you locate a trusted professional in your area. In fact, our recent interviews revealed that 90 percent of homeowners wanted help finding and vetting contractors, so to meet this need, we created a free, digital Contractor Checklist as a simple, step-by-step guide to help you find the right contractor for your project.