top of page
Inside view of a dual pane window

Dual Pane / Double Pane Window Glass Facts

Dual pane windows, also known as double pane, insulated or thermal pane windows, come with two panes of glass. These panes are separated from each other by a spacer filled with air. That air traps winter’s colder temperatures or summer’s heat in between the two windows and forms a barrier that blocks the heat and cold from affecting your home. The energy savings over single pane windows can be as much as 24 percent in cold climates during the winter and 18 percent during the summer in hot climates. That results in lower energy costs and less noise, which can be an important consideration if you live on a busy street.

What is the average cost for a double pane glass replacement?

Replacements can range between $250 and into the 1,000's. The price varies due to square footage, type of glass, thickness of glass, type of low-e, and whether the glass needs to be tempered safety glass or annealed glass.

Signs that your double pane glass needs to be replaced

You’ve probably seen double pane windows that show signs of condensation or discoloring between the panes. This is a sign that the glass is ready for replacement. Normal functioning double pane windows will not show condensation. This usually happens when a seal between the glass panels has failed or has broken. Normal functioning dual pane / double pane windows won’t show condensation or mold. You’ll be able to see through the glass as if it were one single pane, but you’ll get to enjoy the added insulation.

How to tell if your window has single pane or double pane glass

If you’re replacing the glass in your windows and trying to figure out what you currently have, don’t worry. It’s fairly easy to tell whether your current glass is single or double pane. You may not be able to actually spot the two separate panes of glass in a dual pane (even though they’re there), but there’s a little trick to help you find out whether your windows are single or dual paned

Look to your window’s outside edge. This is where the glass meets the window frame. If you have double paned windows, you’ll notice a divider in the center of the window’s outside edges, it can be silver, grey, or black in color. Single pane windows won’t have this divider.

And if you’re still unsure, think about the age of your windows. If they were installed before 1980, they are almost definitely single paned windows.

Can you replace single pane glass in a double pane glass unit?

Homeowners often ask if they can simply replace a single pane of glass in a broken double pane window. The short answer is, "no". Double pane windows are exactly how they sound: two single panes attached around the edges with a sealed spacer and an air space in between the two panes and that are glazed to the window frame. The most energy efficient dual pane windows have argon gas that acts as an added insulator. 

Can you put a single pane glass into a double pane window frame?

No. When you need to replace a double pane glass unit you cannot remove the glass unit and replace it with one single pane piece of glass because the frame was manufactured for the thickness of the double pane glass unit and single pane glass would not fit properly.

Dual Pane Windows

bottom of page