In our homes, ceilings and walls can both absorb and block sound waves. Yet, our windows – or more specifically, the glass panes in them – cannot. If you’re getting outdoor noise coming into your home, the chances are that it’s the windows letting them in.
If you look at it with regards to sound insulation, your windows will be the weakest link. This is due to the properties of glass allowing sound vibrations and waves to pass through them and enter the inside. They’re also the thinnest part that separates you and your home from the outside world.
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Wherever you live, it’s likely that there is outdoor noise that you want to block out. Whether you’re near busy roads, building or construction sites, leisure areas, or even dogs that bark a lot, you’ll probably not want those sounds entering your home.
Noise pollution is a serious problem and, as well as disrupting your life, can also be detrimental to your health. With all this considered, soundproofing windows makes sense.
Types of noise pollution
There are different types of irritating noises that contribute to the noise pollution inside your home. Let’s take a look at some of the problem noises people encounter:
Even if you live quite rurally, you might still have problems with noisy neighbors. One thing about choosing a place to live is that you can never choose who lives next door and so anyone is susceptible to noisy neighbours.
If you live close to bars, restaurants, or shops, you will probably be able to hear them before you can see them. Whether it’s noise from music or from crowds gathering outside, it can be very irritating – especially if you’re trying to get an early night.
Construction or industrial noise
Thankfully, most residential homes are situated far away from construction or industrial noise but this is sometimes a problem. While building noise tends to be temporary, it is still very unsettling while it’s happening.
Road and traffic noise
Unless you live up a country lane, you’re probably going to have traffic noise. It’s almost impossible to get away from the low hum of traffic driving around.
Noise from aircraft
There are reasons why airport hotels source the best soundproof windows: people can’t sleep otherwise!
Aviation noise is a huge problem that can cause serious health issues. Living close to an airport means you’re going to need window soundproofing.
The problems of noise pollution
Noise pollution isn’t just irritating, it’s significantly damaging to our health. Noise pollution can cause or contribute to:
- High blood pressure
- Heart disease
- Cognitive impairment
- Sleep problems
- Poor mental health
- A lack of productivity
In order to understand window soundproofing, we need to look briefly at how sound travels.
How does sound travel?
Sound waves are created when an object vibrates. This vibration has a frequency, which travels through air, water, or solid molecules until a person’s ear picks the sound up. When the sound reaches the person’s eardrum, the vibrations are translated so that the person can hear and interpret the noise being made.
The frequency of sound waves is measured in Hertz (Hz). The human ear can hear frequencies between 20 Hertz and 20 Kilohertz (kHz). As we get older, people can usually only hear up to 15 kHz.
When we talk about how loud a noise is, we use decibels (dB). Here are some examples of common sounds and their amplitude in decibels:
- Normal breathing = 10 dB
- A whisper = 30 dB
- Two people having a conversation = 50-60 dB
- A dishwasher = 70 dB
- City traffic from inside a vehicle = 80 to 85 dB
- A motorbike = 95 dB
- A rock concert = 105 to 110 dB
Understanding how dB work is important. For every 10 decibel increase, the perceived loudness of a noise is doubled. For example, a dishwasher at 70 dB, is twice as loud as two people having a conversation at 60 dB.
Knowing this information is important for anyone considering soundproofing windows in their home.
First of all, let’s look at ways to soundproof windows without installing new ones.
Soundproofing windows without installing new ones
If you’re on a budget or you’re not ready for replacement windows just yet, there are ways you can soundproof windows without breaking the bank (and without a lot of mess too).
Here are four different ways to soundproof your home before deciding to buy new windows:
#1 Seal any window frame gaps
If you want to keep sound out, ensure there are no possible gaps in your window frames where noises can easily enter.
Here are some things you can do to block sound:
- Install weather stripping
- Use acoustic foam (sometimes called a window plug)
- Use sealant
- Use acoustical caulk.
Don’t this will greatly reduce how much noise can get into your property.
#2 Create barriers outside in front of your windows
Putting a barrier in your front yard can be an effective way to block sound pollution. This could be in the form of a fence or hedge. Of course, this won’t block sound completely, but it’ll certainly help to reduce noise.
#3 Invest in some noise cancelling curtains
If you’ve dealt with air gaps and the front yard, we’ll now look at soundproof curtains. Soundproof curtains look like normal curtains but they’re designed to deflect noise that enters your home. Whether it’s from heavy noise pollution or loud neighbors, these acoustic curtains will certainly help.
Of course, you won’t really use acoustic curtains during the daytime. But they’ll certainly help counteract pesky noises at night.
You can get these sound dampening curtains in a range of styles and colors so you’re not limited to drab, functional designs. Lots of these curtains are also blackout curtains, which help create darkness at night too.
Thanks to their insulating properties, you’ll also be warmer in winter and cooler in summer!
However, no true soundproof curtains exist. They simply muffle the sound to a more bearable level.
These curtains will usually be floor-to-ceiling ones that cover the whole windows and go a few inches further on each side. This means they effectively ‘seal’ off your windows and absorb sound coming from them.
A Better Option: Installing specialist soundproof windows
Although all of the above ideas are great soundproofing ideas, a noise problem can be improved most significantly with soundproof glazing.
In order to reduce how much sound comes through your windows, you need to improve the windows and the glass within them.
The last generation was lucky with the introduction of double glazed windows. These windows with two panes and an air space (or gas space) between solved lots of noise complaints and insulation issues. No more scraping ice off the inside of the windows in the depths of winter!
However, there have been significant improvements in windows since double glazed windows first came about. Now, there are even more soundproofing options available – and for some of them, you don’t need complete replacement windows.
Ways to soundproof windows
In order to lower how much noise is transmitted through windows, there needs to be an improvement in the barrier between your ear and the sound. Here are three ways to soundproof windows for a noticeable difference.
- Create bigger gaps between window panes (e.g. install secondary glazing)
- Make the individual glass panes thicker
- Use acoustic glass. Acoustic glass consists of two panes of glass that are bonded with a PVB (polyvinyl butyral) interlayer. This glass makes a considerable difference to sound transmission when compared to normal glazed windows. This PVB interlayer will absorb sound as well as reflect it back to its source.
Here are some of the ways to soundproof windows in more detail.
Using double glazing as soundproofing
If you’re replacing single pane windows with double glazing, then yes, you’re going to get better sound-proofing. Double pane windows will have better sound insulation over single pane windows and in general, the bigger the gap is between the two panes, the better sound insulation you’ll have.
Some double glazing has one glass pane thicker than the other, which works well because the different thicknesses change how sound waves move through the window and thus reduce the noise problem.
Adding window treatments
If you already have double pane windows and don’t want to rip them out to install specialist soundproof windows, you can always add acoustic inserts. These are special panes of laminated glass that are added to the outside of your windows as a sort of soundproof mat.
Typically, these are around 6 or 7 mm thick and are similar to the glass you see on car windscreens. This laminated glass also has the added feature of making your windows more secure as it is difficult to penetrate.
Using triple glazing as soundproofing
You’ll often see triple glazing over double pane windows in areas near to airports or colder places like Sweden.
Having an additional glass pane does reduce noise pollution but not hugely if all three panes have the same thickness.
Using secondary glazing as soundproofing
Unless you’re going for a complete overhaul with new acoustic windows, the most successful type of soundproofing for reducing noise levels is secondary glazing.
Secondary glazing is a popular addition to double glazed windows in noisy places like homes or hotels that are close to airports.
It’s also an option for listed properties that use wooden sash windows, for example.
Secondary glazing is also good for combatting exterior noise from traffic. This works especially well if the panes of glass are not the same thickness.
When installed, you’ll get the best results if the secondary glazing is between 100 mm and 150 mm away from the existing window. For many homes, this might mean a loss of window cill, but this is likely a small price to pay for some.
Ordinary glass used in secondary glazing will help, but for best results, secondary glazing can be installed with acoustic glass, which is capable of reducing external noise by up to 80%.
Other things to consider
If your existing double glazing windows have trickle vents in the window frame, then any soundproofing might be counterintuitive.
If you really want soundproof windows, you’ll need to replace these with special acoustic vents. However, these are often unsightly and large.
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You can save up to 65% OFF your new soundproof windows and doors by using our online cost calculator.
How do soundproofing windows work?
If you’re interested in how noise reduction windows work, we’ll try to explain this in this section.
Essentially, to reduce noise, a denser object has to absorb the sound wave. Or, the wave frequency needs to be disrupted somehow.
When soundwaves hit glass, the pane absorbs the wave’s frequency. It will then vibrate at that frequency and transmit it to the other side.
Some of the sound wave frequency gets absorbed and so it’s reduced during transmission.
However, if you wanted to absorb all of the window noise, you’d need glass that was thicker than a standard wall – even storm windows aren’t that thick!
When you have double glazing, the first glass pane will absorb some sound and so will the second, which means the noise reduction is higher than single pane windows. The bigger the gap, the greater the noise reduction.
If you want the greatest noise reduction, you need to disrupt soundwaves. This can be done with two panes of glass that are different thicknesses. When the thickness changes, the frequency is disrupted more and the noise reduction is higher.
Final thoughts on soundproof windows
Soundproof windows tend to be something more and more people are wanting.
Noise intrusion is a serious problem, which is why window designers and window installers have worked on producing windows with a good sound transmission class.
If you’re not going to install new windows, there are other solutions like installing secondary windows, storm windows, or just using DIY methods like a window plug and acoustic caulk to reduce noise.
For the greatest noise reduction, though, do everything you can: get that acoustic caulk and fill those gaps, install secondary windows, have windows with different thickness panes and get noise cancelling curtains.
Don’t forget, trickle vents can undo all the noise reduction gains you make and low e glass window coatings won’t do a thing to help.
Soundproof Windows FAQs
How can I soundproof my windows?
Look at your window as a whole and ask yourself the following questions? Do the existing windows seal well? Are they single pane windows? Are there obvious gaps in the frame? Begin by sealing any gaps with acoustic caulk, and close your trickle vents (or replace with an acoustic one).
If your windows are single glazed, consider replacing them with double or triple glazing. You could also add secondary glazing too and use acoustic glass.
Cheaper and quicker options for reducing window noise involve using soundproof curtains or acoustic mats.
What are the best windows for noise reduction?
Good quality secondary glazing will make a huge difference to the acoustic performance of your windows. This is especially true if you use acoustic glass and keep the glass-to-glass gap around 100 to 150 mm.
How much does window soundproofing cost?
This isn’t an easy question to answer because there are so many different variables. Some people are happy with quick fixes like plugging gaps and using curtains while others want a complete overhaul with brand new windows and window frames.
For new windows, you need to take into account:
- The window size
- How the window will open
- The glass thickness
- The glass type (toughened glass, laminate glass, acoustic glass, low-e glass)
- Installation costs
Most places will provide free quotations on request and can give you a variety of options to choose from to suit your budget.
Is it possible to soundproof existing windows?
Yes. In fact, secondary glazing is arguably the best sound insulation you could have. It’s also worth looking at the existing windows and resealing them for best results.
If you don’t want secondary glazing, you could always keep your existing window frames and just replace the existing glass with new sealed units or acoustic glass.
Is it possible to soundproof my windows cheaply?
It depends on what effects you wish to achieve. For some people, a pair of sound dampening curtains is enough for them to be able to sleep through street noise, for example.
It’s always worth asking your window company to do a variety of quotes so that you can see what your various options are.