Windows can be poor barriers against traffic noise or even those loud neighbors over the fence. A standard window with 4mm glass does little to insulate against noise, either open or closed. Even the performance of good insulation within your walls can be substantially reduced by poor window design.
Building a new home or renovating an existing one is an ideal time to consider your acoustic requirements.
For neighborhood, traffic and building noise there are a number of convenient window solutions available as mentioned below.
Double glazing
The most effective barrier against noise is to install a secondary window.
The window installed has a space between the two windows, which will significantly reduce the outside noise.
One of the downsides of large gaps though can be the increase in air movement and will reduce your window’s thermal performance.
Another important consideration is the space required for secondary glazing may not be practical in a normal home.
Standard double glazing with at least a 12mm gap is effective at reducing the transmission of medium to high frequencies (human voice). For low frequencies (traffic) using a different thickness of glass in each pane, or incorporating laminated glass, can help to cut noise transmission.
Laminated glass
Laminated glass is the next best option after secondary glazing to reduce noise but is usually more effective at reducing high frequencies such as aircraft noise.
A thicker interlayer than what is commonly used can also benefit acoustic control.
Thick glass
The thicker the glass, the better the sound insulation properties.
The further the sound has to travel through the glass, the more sound waves will drop off.
Thicker glass is a common solution to reduce low frequency sounds like common traffic and neighborhood noise.
Noise reduction table
The table below shows the percentage noise reduction for various options compared to 4mm glass.
| Voice noise reduction | % | Traffic noise reduction | % |
|---|---|---|---|
| Single glazing | Single glazing | ||
| 6.38mm laminated glass | 13 | 6.38 laminated glass | 24 |
| 10mm glass | 24 | 10mm glass | 38 |
| 10.38mm laminated glass | 29 | 10.38mm laminated glass | 43 |
| Double glazing | Double glazing | ||
| 4mm/12mm gap/4mm | 19 | 10mm/12mm gap/6.38mm laminated glass | 46 |
| 10mm/12mm gap/6mm | 34 | 6mm/100mm gap/4mm | 57 |
| 6.38 laminated/8mm gap/4mm | 46 |
Tips for reducing noise
- Use thicker glass to reduce traffic noise
- Use double glazing to reduce high frequency noise (voices)
- Install windows away from noise sources
- Avoid placing windows and doors directly opposite or adjacent to neighbouring houses or units
- Seal cracks and gaps around windows to achieve better sound reduction
- Check manufacturer’s claims of noise reduction for both high and low frequencies
- Consult an acoustic engineer
