When Building An Urban Home, Use Double-Pane Windows To Block Out Noise

Posted on: 29 January 2016

Living in the middle of a major metropolis offers many benefits, but it has one big downside: noise. The constant sounds of cars driving by, trucks backing up and sirens ringing can make having any peaceful, quiet time at home difficult. If you're building a home in the center of a city, ask the window installation company your contractor is working with to put in double-pane windows. These windows will keep a lot of the city's sounds from getting into your downtown home.

Three Types of Windows Are Used in Residential Construction

There are three kinds of windows used in residential construction: single-, double- and triple-pane. (Some manufacturers refer to them as single-, double- and triple-glazed windows.)

These terms tell you how many pieces of glass, or panes, are in a window. Single-pane windows have one piece of glass, while triple-pane windows have three. Windows that have two or three panes also have air pockets between the glass.

You could theoretically have soundproof windows installed in your home. These windows block out up to 95 percent of outside noise, but they're prohibitively expensive for most residential construction projects. Soundproof windows are usually reserved for rooms that must be entirely silent, such as hearing test booths and recording studios.

STC Ratings Measure Sound Insulation

Every single-, double- and triple-pane window has a Sound Transmission Class (STC) rating (as do all building materials). STC ratings objectively measure how well a building material guards against sound. The scale used is exponential, so just a small difference in ratings can be significant. You can use the following list of ratings differences as a reference when comparing ratings:

  • an increase of 2 points is negligible
  • an increase of 4 points is noticeable
  • an increase of 10 points equates to a 50 percent improvement

Single-Pane Windows Have Low STC Ratings

Single-pane windows have STC ratings between 24 and 26, which is low. For reference, the average exterior wall has a rating of 34 to 38, meaning it blocks out 50 percent more sound than the best single-pane windows.

If you opt to have single-pane windows installed in your home, be prepared to hear all of the city's sounds. Everything from loud sirens to mild traffic, and perhaps even people's voices, will come through the windows.

Double-Pane Windows Have Good STC Ratings

Double-pane windows' STC ratings are much closer to that of a typical exterior wall, and, in some cases, these windows have better ratings. Double-pane windows with laminated glass have ratings of 35 to 38. According to these numbers, the best double-pane windows will block out over 50 percent more sound than the best single-pane models.

Double-pane windows are so effective because sound must travel through two pieces of glass and an air pocket. Many sound waves don't make it through all three levels and are blocked.

Triple-Pane Windows Aren't as Effective as Double-Pane Ones

Counterintuitively, adding another air pocket and pane of glass does not provide better sound insulation. Although triple panes have a total of three pieces of glass and two air pockets, they're not more effective than double-pane windows. In order to keep the entire window approximately the same thickness as other windows, the pieces of glass and air pockets have to be made thinner. Sound waves can more easily travel through these thinner barriers than the thicker ones in double-pane windows.

Thus, if you're building a downtown home, double-pane windows are the best choice for blocking out sound. They're the most effective of single-, double- and triple-pane windows, and they won't break your budget like soundproof windows. Talk with the window installation company that's putting your home's windows in, and see what the specific STC ratings for their double-pane windows are. You'll be glad you invested in this type of window when you want to enjoy a peaceful, quiet evening in your new home.