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Double-Glazed Windows – Everything You Need To Know

By June 8, 2021August 4th, 2021Windows
double glazed windows

Older homes have a lot of uniqueness to them. Sometimes they have different architecture, roof design, and often single-paned windows. However, single-paned does not last as long and not much in the way of insulation, so many homes now a days have double-glazed windows. But what are double-glazed windows? Double glazed windows are also known as double-paned windows or an insulating glass unit. They are two panes of glass that are set into a frame and then have a space for an air pocket so they can insulate a room.

Let’s take a look at why you should know about double-glazed windows, their advantages, R-values explained, how to improve window efficiency, other areas to keep an eye on, price for windows, and when to call a professional.

Why You Should Know About Double-Glazed Windows

Double-glazed windows started to become part of homes in the 1970’s. These are the windows that homeowners now buy for replacement, or builders use for new construction. It is important to know about these windows in case you need yours replaced or you are trying to figure out the best windows for where you live.

Advantages of Double Glazed Windows

  • Double-glazed windows are energy efficient, are a great insulator and prevent heat loss. This is a lot better than single-paned windows.
  • These windows stop drafts through the window and the frame.
  • They keep noise to a minimum and prevent unwanted heat from coming into the home in the summer.
  • Better security on a home with double glazed windows.
  • The gases make the windows more efficient. However, they are more expensive when the gap between the panes is filled with a gas of krypton, argon, or xenon instead of air.

The Difference Between These Gases

  • Krypton– more expensive so it is usually in triple-paned windows and does well in thin gaps and can reduce energy by 40%!
  • Argon– is the one that is most common and affordable. It also helps improve thermal insulation efficiency and often combined with low E energy efficient windows.
  • Xenon– known as “cutting edge technology” and the most expensive of the three. It is more commonly found in commercial, not residential buildings.

Here is a great video about 10 questions to ask when considering double-glazed windows.

R – Values Explained

As a consumer, you want to know what R-Values are. They are to help you understand the thermal resistance you expect from a material. R-value measures the material’s resistance to energy transfer and the higher the R-value, the higher the insulating value of the window, the greater the resistance.

Here is a chart that shows the difference in the R-values for different windows. Keep in mind, these are only estimates and R-Values vary from window to window.

Pane Air/Gas Coating R-Value
Single None None 0.9
Double 1/2″ of air None 2.084
Triple 1/2″ of air None 3.226
Double Argon Low-E (1 coating) 3.846
Triple Argon Low-E (1 coating) 5.433
foggy window needs replacing

How to Improve Window Efficiency

  1. Use thick thermal curtains – this type of curtain raises the window’s R-value. This is because it keeps the inside of the home warmer.
  2. Insulating film for the window – adding this can help with keeping the heat and cool air inside the home. This will keep it from escaping to the outside.
  3. Caulking around the windows – you may need to do this on older windows to keep air and water out.
  4. Foggy windows need replacing – windows that have lost the gas can’t be fixed and need replacing. However, you can buy yourself some time doing the following: Drilling holes to clean the inside and point a fan towards them to dry it out. Another option is you can put a dehumidifier near the window and see if that helps pull the moisture out.
  5. Replace single-paned windows – it is a good idea to have them replaced for the reasons mentioned above. If these are in your home, then this means your home is older. This is a good reason for you to be aware of plumbing problems in old homes as well.
  6. Plant Shady Trees – Providing shade to your home can easily drop the thermal transfer of heat into your home.
impact resistant windows on a beach house

Other Types of Windows

Impact-Resistant Windows

Impact-resistant windows are often used in coastal communities so the windows on the house can survive strong winds and storms. They are also good for keeping out unwanted humans, and for tornados to name a few. These windows have multiple layers of glass that bond together and installed inside sashes to hopefully survive the harsh conditions that can happen, especially in hurricane and tornado-prone states.

Other Areas to Keep An Eye On

Continue to check around the windows

It may look like the window leaks when it rains. If you are seeing this happen, it can be a number of reasons. These might be poor insulation, wall leaks, improper overhangs, clogged gutters, or weep holes to name a few.

Perform spring or summer maintenance

This is around the windows checking for leaks, but also around the home including the HVAC, the refrigerator, garden, and gutters to name a few. The goal is to make sure everything is working so there are no surprises, if possible.

mold in the home

Check for mold in the home

No matter how careful we are, it is possible for mold to show up in the home. Sometimes it is because of a builder error, or too much humidity in the home, or even leaks. Whatever it is, keep an eye out for it when you are checking the home and get rid of it as soon as possible.

single pane window
Old single-pane window

Prices for Windows

Windows will vary in price:

Single-pane windows are still available in stores and cost about $100 each.

Double-glazed windows are close to $300 or more, depending on how big the window is.

Triple pane windows are fancier and have a higher bill of over $300.

When to Call a Professional

Call a professional if you need help with your windows, deciding what type is best for where you live, or if you are having other issues. A professional wants to help you and often can save you money by pointing you in the right direction.


Windows can be difficult to figure out and know which one is right for the home. There are single-pane, double-pane, and triple-pane as discussed above. Deciding what you need for the home is a big decision and keeping up the maintenance is even more important. Atkinson Inspection Services can inspect your windows during your home inspection in Orlando, Clermont, and the Villages.