A Beginner’s Guide to Double Pane Windows (And Why They’re a Great Choice)

Double pane windows are the standard in today’s new construction and replacement windows. They’re energy-efficient, affordable, and long-lasting.

If you’re window shopping, you have many decisions, including style, frame material, and glass type. In most cases, going with a double-pane window makes more sense than single and triple-pane options.

Read this guide to understand your double-pane window options and how to choose the best one for you.


What is a Double Pane Window?

What is a Double Pane Window?

A double pane window is an IGU or insulating glass unit, also known as a double-glazed window. It features two sheets of glass with a spacer separating them. Manufacturers fill the space with air or a dense gas like krypton or argon for better insulation.

Double pane windows are the industry standard, and you can find them in all window types, including double-hung, single-hung, casement, picture, bay windows, and more.

Double Pane vs. Single Pane Window

Double Pane vs. Single Pane WindowView in gallery

A single pane window features one sheet of glass. Single pane windows are standard in older homes, especially those featuring wooden window frames. A double-pane window features two sheets of glass with an optional insulating gas filling.

Energy Star estimates that replacing single pane windows with Energy Star double pane windows saves $125 to $340 per year in energy bills based on a 2,000 sq. ft. one-story home.

Most manufacturers don’t offer single pane windows due to low energy efficiency.


Double Pane vs. Triple Pane Window

Double Pane vs. Triple Pane Window

While a double pane window has two glass panels, a triple pane window has three. Triple pane windows offer superior energy efficiency, helpful in areas with extreme cold or heat. But with the extra energy efficiency comes a 10-20% higher price.

It can take 30 years to recoup the cost of a triple pane over a double pane window. Because of this, a double-pane window is the better option for areas with mild climates.

Types of Insulated Glass in a Double Pane Window

Manufacturers can fill the space between the panes of double-glazed glass with air or one of three types of gas. Gas fillings provide better insulation than air but cost more. Here are the types of gas used in order of least expensive to most expensive.

  • Argon-filled double pane windows – Argon is the most common gas filling in double pane windows. It is six times denser than air for better insulation.
  • Krypton-filled double pane windows – Krypton is another gas, six times denser than argon. It’s also more expensive.
  • Xenon-filled double pane windows – Xenon is the densest gas used as a window insulator and also the rarest. The cost of Xenon usually isn’t worth the energy efficiency it provides.

In addition to insulative gas fillings, you can get a double-pane window with a Low-E coating. Low-E stands for low emissivity and helps keep heat from escaping the home. Solar control Low-E coatings prevent solar heat from entering the house, which is helpful in warm climates. 

How Much Do Double Pane Windows Cost?

Double pane windows are the standard. The amount you’ll pay for a double-pane window depends on window size, style, and brand. For example, a standard double-hung, double-pane window costs about $600, but prices range from $200 to $1,200.


The Pros and Cons of Double Pane Windows

There are more pros than cons to double pane windows. Here’s what you need to know.

Pros:

  • Energy efficient – Double panes and insulative gas make these windows energy efficient.
  • Widely available – As the standard, it’s easy to find double pane windows from any brand.
  • Affordable – Many options to choose from that affect price and energy efficiency.
  • Offer some noise reduction – The dual panes offer noise reduction properties.

Cons:

  • Can’t replace the glass – If the glass or seal breaks in your window, you must replace the entire IGU.
  • Not as energy efficient as triple pane – If you live in a climate with year-long frigid temps, triple pane might be a better bet.

Should a Double-Pane Window Have Condensation?

Double-Pane Window With Frame Section

During the winter, when temperatures drop, and the house is heated, it’s not uncommon for some condensation to develop on the external glass of a double-pane window. But, condensation should not form between the glass panes.

If there’s condensation between the glass panes of your double-pane window, the seal is broken, and you’ll need to replace the unit or entire sash that’s fogging up.

What is the R-Value of Double Pane Windows?

The R-value of double pane windows depends on how thick the glass is, how big the space between the panes is, and whether or not the glass has a Low-E coating. Most double-pane windows have an R-Value of 2.

Can You Repair Double Pane Windows?

You can’t repair double pane windows. If the glass breaks or the seal weakens, you must replace the entire unit. You can do this by contacting the manufacturer and ordering a replacement sash or taking the broken portion of the window to a glass repair shop.

A glass repair shop can take proper measurements and assure you get the correct type of glass. 

How Long Do Double Pane Windows Last?

The seal on a double pane window will last 10-25 years, depending on the brand. Aside from quality, pressure washing your windows can also lead to a broken seal. 

When you notice condensation between the glass panes or feel drafty air leaks, it’s time to replace your double pane windows.

Frequently Asked Questions (FAQ)FAQ

How do you clean double pane windows?

There is no unique way to clean double pane glass – use a glass cleaner and lint-free cloth. Avoid ammonia-based cleaners and scrapers if your windows have a Low-E coating.

Can you put double-pane windows in a mobile home?

Yes, you can find double-pane mobile home windows. And in some cases, you can purchase a standard double-pane window and fit it in a mobile home as long as it’s the same size as the one removed.

Can you open double-pane windows?

Double-pane refers to how many layers of glass are in the window, not how the window operates. There are fixed and operable double-pane windows in all sizes and styles.

Can you purchase double-pane impact-resistant windows?

While not all double-pane windows are impact-resistant or hurricane-proof, you can find these options. Double-pane impact-resistant windows will give you an extra layer of protection.

Final Thoughts

Double pane varieties are a great choice if you’re looking for new windows. They’re today’s standard, available from all popular manufacturers in all styles. You can customize a double-pane window’s energy efficiency by choosing insulating gas filling and Low-E coatings.

While double-pane windows are more expensive than single-pane options, they’ll keep your home more comfortable and save you money on energy bills.