Are Replacement Triple Glazed Windows Soundproof?

Reducing Outside Noise Requires Special Acoustic Designed Glazing

Triple Glazed Windows | Are They Soundproof?

17 June 2019

Are triple glazed windows better than double glazed windows for soundproofing? Windows are an excellent starting point to dampening excess noise from outside., but they require special acoustic configuration to greatly reduce outside noise.

It’s no secret that excessive outside noise, such as traffic on a motorway or screaming kids from a nearby playground, can be a common displeasure to your day to day life within your home.

How To Manage Noise With Your Windows

To understand how soundproof your new triple glazed windows are you need to look at the Sound Transmission Class (STC) rating which is measured in decibels (db). A windows STC rating indicates how much sound waves are reduced. A high STC rating indicates to a high reduction in sound transmission. Each point can make a significant difference.

A good rule of thumb is a change of 10+ db which will roughly cut the sound in half.

How Do You Reach A High STC Rating With Your New Triple Glazed Windows?

There are a couple of factors one needs to take into consideration when trying to achieve a high STC rating with windows.

Triple Glazed Windows Soundproof Diagram
Key Window Factors To Increase STC Rating & Reduce Outside Noise
  • A) Spacing Between The Glazing: Increasing the space between the glazing is the most important factor when trying to achieve a high STC rating. Signature incorporate non-toxic argon gas and warm-edge spacer bars which help increase STC ratings while improving overall energy performance.
  • (B) Varying Glazing Thickness: Varying the thickness of the window panes has a great impact on the sound stoppage ability of your windows. Having different glass thickness will mean that the sound frequencies won’t vibrate at the same rates when hitting the glass and thus dampen the sound from the outside. Essentially, the sound wave frequencies will reflect due to the various glass thickness.
  • (C) Laminated Glass: Laminated glass is an excellent solution for dampining sound wave frequencies.
  • Weatherstripping: Utilising triple sealed weatherstripping in your windows vastly improves the STC rating and overall airtightness performance.
  • Installation: Your windows STC rating is only as good as your installation. Investing in a window company with an experienced in-house installation team is crucial to achieving a better overall noise reduction performance.

What STC Rating Should My New Triple Glazed Windows Be?

What STC rating should I be achieving with my new triple glazed windows? A good sound transmission class for windows is an STC rating of  35+. The table below highlights the different glazing combination options are available and what STC rating you can expect to achieve.

STC Window Rating Table

As you can see, as we start to increase the size of the window panes and add greater air space between, the STC increases correspondingly. Some window manufacturers will sacrifice on a slim window profile to achieve a better overall performance rating.

Signature has over 25 years installing high performing STC windows into homes across Ireland and the UK. See how Signature reach an STC Rating of 44 db+ while maintaining a slim aluclad window design in this replacement project in Dalkey, Co. Dublin.

Aluclad Casement Windows Replacement Dalkey