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What are Double Glazed Windows?

Dakota Davis
Dakota Davis

Double glazed windows are made from two panes of glass that are separated by a layer of air or gas and then sealed. They are designed to provide a better barrier against outside temperatures than single paned windows because the two layers of glass and the buffer layer act as insulators. The glass used features a specially-coated surface that re-radiates heat in cold months and prevents heat from entering during hot weather. Originally created for extreme climates, double glazing is now widely used in nearly all locations, both for new construction and as replacement windows.

Many kinds of glass can be used to create double glazed windows, from regular to decorative, but the most common selection is high performance Low Emissivity glass. Low E glass contains a virtually invisible metallic layer in the pane of glass, along with a special coating that can be selected in different glazes to accommodate a range of climates. High-Solar-Gain glass is preferred for areas with cool summers and very cold winters because it reduces heat loss and increases heat, or solar gain. Moderate-Solar-Gain glass lets in a smaller amount of heat without losing any light and is often chosen in areas with mild summers and winters. Low-Solar-Gain glass offers the highest protection from UV rays and is selected in areas with extremely hot summers and mild to moderate winters.

A layer of air is often trapped between two panes of double-glazed glass.
A layer of air is often trapped between two panes of double-glazed glass.

Double glazed windows with an inert gas — most often argon — between them are considered a better insulator than those with just a sealed pocket of air. Gases like argon allow less heat to escape and less cold to enter because they have a higher density, therefore offering a better buffer than air. Double glazed windows created in factories are sealed airtight to further enhance insulation and to eliminate the potential for condensation to form between the panes.

Double-glazed windows are attractive and energy efficient.
Double-glazed windows are attractive and energy efficient.

There are many of benefits to double glazed windows, and their presence or addition is generally considered to increase the value of a home. The most significant benefit is their ability to conserve energy and reduce costly energy bills, since they keep homes warmer in the winter and cooler in the summer. They are also relatively low maintenance, offer better insulation against noise, and provide a measure of increased security, since each layer of glass is another barrier against intruders. Windows with high UV coatings also protect people and prevent furniture, floors, rugs, and photographs from fading and sun damage.

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Discussion Comments


Windows are the only sources to let the fresh air come in your rooms and office. The changing weather is very pleasant and one can’t stop to enjoy the cool breeze and the freshness of the nature, but at times you need to maintain cleanliness and room temperature, which is only possible with the installation of double glazed windows. It has been considered a masterpiece in the category of glasses and mirrors, as it prevents the heat and cold from outside the premises to maintain a hygienic and lively home environment.


It is really a good thing that double glazing windows have been invented. It is a really helpful material to prevent heat during summers and hold heat during the winter. I'm trying to look for affordable double glazing prices, so I can install them at home.


Double glazed windows are a great thing to install if you are looking to make your home more energy efficient. It has been estimated that each home loses up to 20% of their heat just by having poor insulation. With the rising cost of gas and electricity the savings for having good windows installed can really add up.

If you are choosing double glazed windows with the idea that you will better insulate your home, you should buy the ones that come with an 'energy saving recommended' sticker, as these windows have been tested by professionals to make sure they live up to their energy saving claims.


Double glazed windows are great for their insulation properties but unfortunately are prone to misting up and getting condensation between the gaps in the two panes of glass. Generally this shouldn't happen before the five-year mark of ownership but sometimes the seal’s breakdown quicker and the windows will need to be repaired.

Most double glazed windows come with a ten-year warranty, so if you experience condensation and misting call your company and get the windows fixed. Leaving them as is not only looks terrible but you are leaving your home open to moisture damage. If it takes a long time to get the company in, make sure you cover the windows so you don't get mildew forming in your home.


Three of us in the neighborhood were talking about double glazed windows. We had all gotten them about a year ago.

One man was saying that his brother was having a house built for his family. His brother said it is more than worth the extra money to have double glazed windows put in new construction. Much better than having to replace them later, he told us.

Our neighbors were all saying that they were so glad they had double paned windows. We are saving energy and the energy bill is going down. And there is insulation against the traffic noise outside. These windows are just great!


It was a happy day when we finally got our double glazed windows! We live in the Pacific Northwest, so we got the Moderate-Solar-Gain glass with argon gas in between.

Before we got double glazed windows, we had to turn the furnace way up to stay warm. My daughter used to sit on top of the heat register until it got warm enough in the house.

I noticed the house was warmer in the winter. But on hot days in the summer, it didn't feel much cooler than before.

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    • A layer of air is often trapped between two panes of double-glazed glass.
      By: stocksolutions
      A layer of air is often trapped between two panes of double-glazed glass.
    • Double-glazed windows are attractive and energy efficient.
      By: digerati
      Double-glazed windows are attractive and energy efficient.