Double Pane vs. Triple Pane Glass

Do you know there are different types of glass used for windows? There are! We’re going to go over the basic differences of double and triple pane glass, and some advantages of each.

To put it simply, double pane windows have two layers of glass, and triple pane windows have three layers.

Both double and triple pane windows come standard with high solar heat gain glass (HSG), but also have the option of low solar gain (LSG) glass. Since our heating degree days are higher than our cooler degree days, HSG is typically the most common choice.

When it comes to triple pane windows, there are tons of advantages. Let’s go over a few:

  • Because of the extra pane of glass, and a subsequent air pocket, they offer a higher R-value (which is a measurement of thermal resistance, or of energy moving from hot areas to cold areas through the window).
  • They retain heat inside the building better for the same reasons, which is reflected in their U-value (which is the rate of heat flow through the window).
  • They reduce the amount of condensation, since the interior pane of glass is typically warmer than the same pane of glass on a double pane window.
  • They reduce more sound transmission into the house than double pane.

The main advantage of double pane windows is the price. 

Also, because of their lower R and U values, double pane windows offer a higher solar heat gain coefficient (SHGC) than triple glaze because they let in more heat from the sun. This is an advantage in the winter, but a disadvantage in the summer!

Ultimately, choosing double or triple pane glass depends on a few variables, which our team can go over with you when the time comes. But, as a general rule:

  • Larger windows benefit more from triple pane than smaller windows.
  • North facing windows benefit more from triple pane than south facing windows.
  • We only suggest LSG for windows in small rooms, or rooms with no direct cooling source, and that facing directly south. They’ll keep the room cooler in the summer. Other than that, HSG is typically the best option for homes in our climate.

Still have questions about choosing windows? Get in touch with our team – we’re happy to help!