How to Soundproof Windows

Soundproofing and noise cancelling windows are misleading terms. There is no magic solution to 'soundproof' windows that can turn a residential house next to a noisy road, trainline or airport into a silent space.

'Soundproof window' is a false claim – they don't exist!

Noise reduction windows with modern glazing units can make a significant difference in the amount of noise coming through a window to make your home much more peaceful. But, the glass in a residential window can never block out all noise pollution.

How Does Soundproofing Work

Soundwaves need to be absorbed by a dense object, or the frequency of the soundwaves needs to be disrupted to reduce or eliminate sound.

When a soundwave hits glass, the glass absorbs the frequency of the wave, begins to vibrate at the same frequency and then transmits that frequency to the other side of the glass.

Some of the frequency is absorbed by the glass and then the soundwave is reduced as it is transmitted through the other side. But, the glass would need to be thicker than a brick wall if it was to absorb all of the frequency vibrations to stop it from being transmitted.

By placing two panes of glass apart from each other, the first pane of glass absorbs some of the soundwave energy and then is reduced considerably more by the second pane. The wider the gap between the panes of glass, the more the soundwave is reduced.

The most efficient way to reduce noise is to disrupt the soundwaves. Using two different thicknesses of glass close together acts to disrupt the frequency, which reduces the oscillation and vibration. Therefore, reducing the level of noise transmitted.

A noise-reduction window can feature noise-reducing double glazing unit made of a 6mm Low Iron outer pane and 6.8mm acoustic laminated inner pane. 

Noise reduction windows work by:

• The thickness of the glass
• Asymmetric thicknesses of glass to disrupt the soundwaves
• Argon gas between the panes
• Depth of gap between the panes
• Sound dampening laminate between panes

Sound is much more difficult to contain than light because a soundwave has a longer oscillation than a light wave and the soundwave can diffract around corners to find its way through any small gaps.

If you have a trickle vent in your window, the sound can travel through the vent. If the seals in your double glazing are degrading and gaps are being formed, the sound can travel through those.

The frame construction and the installation of a window are as important as the glass used.

Total silence and the absence of external noise can be disorienting. An anechoic chamber of absolute silence is generally an uncomfortable space as the ear would begin to hear phantom noises.

Types of Noise Pollution

Over three-quarters of the UK population are stressed and harassed by noise and finding a quiet space for respite is becoming a rare thing.

• Neighbours
  Even in the countryside, houses in isolation are few and far between. It's just not possible to be out of the hearing range of other people.
• Leisure
  Living near a pub can be challenging with people leaving late at night after a few drinks. However, Landlords can lose their license if they ignore noise complaints.
• Industrial & Construction
  Noise from manufacturing and construction sites have the lowest complaints, but they still impact those who have to suffer from the noise.
• Traffic and road noise
  Constant road noise is a considerable current day problem.
• Aviation noise
  One million people are exposed to aircraft noise above recommended limits (HoC study).

Source

In Greater London, for every 50 people, a complaint about noise is made. Across England, one complaint for every 160 people is made (CIEH)

Noise Pollution Has a Significant Impact on Our Health, Resulting In:

• Heart disease and high blood pressure
• Cognitive impairment in children
• Sleep disturbance
• Tinnitus
• Annoyance and Mental well-being
• Productivity

Why Is It Difficult to Stop Noise Coming into My Home?

Sound is difficult to contain because a soundwave can diffract around corners to find its way through any tiny gap.

A standard-built home will have lots of little gaps that sound can find its way through - and sound can also travel through solid walls, floors, ceilings and window panes. You might know that you can hear traffic or voices talking outside, but it's not always obvious where the noise is coming from or how it's getting into your house.

The most common points of entry are fireplaces, air bricks, floors and ceilings, trickle vents and badly-fitted doors or windows.

How to Reduce Noise Coming Through Windows

Apart from installing noise reduction windows, there are a few alternatives that can reduce noise coming through your windows.

Both of these options work on the basis of applying a form of secondary glazing to your window.

Secondary glazing is one of the most efficient ways to reduce noise levels coming into your home. The wider the distance between your windows and the secondary layer, the more the sound is reduced.

However, the drawback to secondary glazing is the practicality of having it fitted. Not all window frames have enough depth to facilitate the installation. And, the aesthetic of secondary glazing can be off-putting.

• Acoustic inserts
  This is the more economical way to add a layer of secondary glazing. A pane of acrylic within a frame is made to measure to sit inside your window frame. Inserts are DIY installed.
  
  If you have frames that are not square, it can be difficult to get a perfect fit and inserts can be cheap looking. The acrylic panes are noticeably thin and flexible, which reduces the clarity of the window.
  
  
• Secondary glazing panels
  Made-to-measure secondary glazing panels are professionally fitted to the inside of window frames. The panes will slide horizontally inside the frame to create a snug fit and seal.
  
  Good quality secondary glazing with a single glass pane can be highly efficient to reduce noise. But some people don't like the reduction in the depth of your window frame and how it changes the aesthetic of a window.
  
  Watch out for cheaper acrylic-based secondary glazing that does not have the clarity of glass.

How Can I Soundproof My Windows Cheaply?

If you want to reduce the noise coming through your windows but don't want to replace the windows or use secondary glazing, you have a few backup options:

Plant Hedges or Fence Front of the Window

If you have a house facing a busy road with garden space at the front, or your house backs onto a train line you can use natural elements to dampen the sound.

Dense shrubs, hedges, thick trees or a high solid fence will all help to reduce the transmission of sound towards your property. So, when the soundwaves hit your windows they are already reduced.

By combining noise reducing windows with the use of hedges and shrubs the noise reduction will be even more enhanced.

Plug All Gaps, Acoustic Caulk and Weatherstrips

As mentioned above, sound can diffract around corners and will find its way through any gaps. You can tell that the seals on your windows are starting to fail because the noise from outside starts to get louder.

It's not just the edges of the glass that can fail. If your window hasn't been installed efficiently, there can be small gaps that leak noise.

Use specialist acoustic caulk and fit weatherstrips around the frames to eliminate as many gaps as you can. If the gaps are too big, the only solution is to replace the windows.

Use Sound Dampening Curtains or Shutters

Heavy fabric can make a surprising reduction in noise levels. Specialist sound dampening curtains have several layers of fabric - polyester being the best - which creates a dense fabric that can absorb sound vibrations. Sound deadening fabrics also help to absorb sound that bounces around open spaces.

Wooden plantation shutters that are becoming increasingly popular make a notable difference in warmth and sound. The classic solid wooden style shutter is especially efficient at reducing noise as it's installing a solid barrier to your windows every evening.

Window Film

Noise reducing glass has a laminate coating on one of the panes of glass that helps to absorb more sound waves as they transmit through the glass.

Window film is an instant DIY fix that can reduce noise by a small amount. However, the film can obscure the window to lose the clarity of the glass. And, unless it's professionally applied, it can cheapen the aesthetic of the window.

All of the options above can help to reduce noise before you install new windows. You can also read how to soundproof a room for more ideas on how to deal with pervasive traffic noise or noisy neighbours.

How Much Do Soundproof Windows Cost?

All window costs are dependent on many factors such as installation, style of frame, size, and finishing, so we don't offer an off-the-shelf price for the cost of our noise-reduction windows.

As a guideline, a noise-reducing window can cost from £500 up to £3,200 per window depending on the different options available.

However, the more windows you purchase (and the ease of installation) will reduce the cost price per window.

If you are considering installing noise reducing windows then please contact us so we can help you might the right choice for your needs at the most cost-effective solution.