When it comes to window sound insulation there are two good choices – either acoustic glass or triple glazing. Here we explain which of the two is best for protecting against sound.
There is no definitive answer to the question, ‘Which is best for sound insulation: acoustic glass vs triple glazing?’ because the best type of window sound insulation depends on a number of factors, such as:
- The size of the window;
- The window’s shape;
- The type of noise that needs to be blocked out.
However, as we will see, acoustic glass is usually better at blocking out sound than triple glazing.
This is because acoustic glass is made up of two or more layers of glass, with a layer of laminate – though some windows use acoustic foam – sandwiched in between.
This gap between the panes and the laminate helps to prevent sound from passing through the window, whereas triple glazing usually just consists of three layers of glass – which makes it more difficult for sound to pass through.
However, acoustic glass tends to be more expensive than triple glazing, so it is important to weigh up the pros and cons of each option before making a decision.
Let’s take a closer look at the potential choices that homeowners have to insulate their homes from sound.
What are the glazing options for reducing noise pollution?
When thinking about the glazing options for your home when it comes to reducing noise, especially road noise issues, you have these choices:
With just one pane of glass, this is the cheapest version, and you won’t block out much noise. This is not recommended for a home next to a busy road.
Double glazing has two layers of glass instead of one, as standard glass windows will have. This helps to keep noise out which makes it a popular (and cheaper) choice for homes and businesses.
Triple glazing has three panes of glass with an airspace in between. It is designed for improving your home’s thermal efficiency. It offers very good noise reduction capabilities.
Acoustic glass is made up of two or more panes of glass with airspace in between. The panes are usually different thicknesses with a laminate covering so that the acoustic effect is greater.
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How much difference does acoustic glass make?
Acoustic glass can make a big difference in the amount of noise that you hear inside your home because the glazed units have two or three layers of glass with a space and a laminate bond between them.
Sound is absorbed instead of passing through the window to reduce how much you hear and it is a popular choice for people who live in noisy areas.
Essentially, acoustic glass is specifically designed to improve the acoustic properties of a building, but it will need acoustic window surrounds to be really effective.
And because of the cost of acoustic windows, it might be worth considering having just one room fitted with this type of noise reduction window.
How much difference does triple glazing make?
If you want to improve the insulation AND the acoustic performance of your home, then triple glazing can be more effective than acoustic glass. That’s because:
- Much of the noise in a room comes from the window, so by installing triple glazing you can reduce noise levels by up to 70%;
- Triple glazing improves your home’s insulation by up to 73%.
Installing triple glazing will lead to lower noise levels and better heat insulation – you could save hundreds of pounds every year on your energy bills.
Disadvantages Of Triple Glazing
When asking ‘is triple glazing worth it?’ it’s important to also consider the negatives:
- Energy savings don’t outweigh the installation cost
- Extra glass reduces the amount of light coming in
- Condensation can form on external glass
The energy savings you’ll get are, unfortunately, not enough to outweigh the costs. You could be looking at around 50 years to save the same amount of money on energy as it cost to install the windows (by which time, you’ll be long overdue for replacing the windows again!). However, double glazing does not fare any better on this.
We might add windows to let light in, but, glass does actually block out a small amount of light. That means double glazing lets in slightly less light than a single pane of glass and three panes together lets in slightly less light than two panes together. However, the amount will be so small you’ll barely notice.
A final disadvantage is that while you’ll reduce the amount of condensation on the inside of the windows, you may find more condensation on the outside of triple glazed windows. That’s because the let less heat out of your house, leading to colder, more condensation-prone panes of glass externally.
Cost Of Triple Glazing
The cost of triple glazing varies considerably depending on where in the country you live, which supplier you choose, and the size and specification of the windows you select.
However, the typical cost of a 3 bedroom property with 15 windows is around £7,000. This is around 30% higher than the cost of installing double glazing on the same property.
In both cases, the energy savings will not outweigh the installation costs over the lifetime of the windows. Therefore, installing any form of new windows is a cost, not an investment.
Effect Of Triple Glazing On The Value Of A House
So, we’ve established that installing triple glazing will cost you more money than it saves you. But, does it affect the value of a house?
As triple glazing is still relatively rare in the UK, a house with it is certainly likely to have a novelty value to potential buyers.
With Energy Performance Certificates (EPCs) now legally required for all properties up for sale, buyers are increasingly putting higher values on more energy efficient homes. Therefore, a triple glazed property is likely to attract more interest and a higher sales price than ones without it.
However, it’s unlikely your property will increase in value by more than the cost of installation. Therefore the value of your property shouldn’t be a major influence on whether or not you choose to install it.
How effective are acoustic windows?
If sound pollution is an issue for your home, or you simply want to soundproof it, then acoustic glass is certainly worth considering.
That’s because it has been designed to reflect, dampen and absorb sound waves.
The acoustic glass that a glazing firm will use is laminated which means it has been coated in a plastic laminate or resin.
Usually, this laminate is used to toughen the glass to help improve its acoustic properties and help prevent it from breaking should an object hit it.
The most common type of laminate is polyvinyl butyral (PVB) which delivers a strong bind for the panes of glass to absorb sound but does not compromise on optical clarity.
After all, there’s no point in having acoustic glass to prevent sound if you cannot see through the window!
Should I replace double glazed windows with acoustic glass?
It may sound as if it’s a straightforward undertaking to replace double glazed windows with acoustic glass, but there are two issues:
Acoustic glass is heavier
While you may be considering switching to acoustic glass, your double-glazing window frames may not be able to support acoustic glass which tends to have thicker glazing.
Acoustic glass surrounds
For acoustic glazing to work effectively, you need to have the window frame and its surrounding area acoustically treated also.
This means you really should speak with a firm with experience in fitting acoustic window panes and they will be able to advise on what you will need.
Will installing thicker glass help reduce noise pollution?
A potential solution for reducing noise in your home is to install thicker glass windows.
The idea is that since glass does not conduct sound very well, then a thicker pane will make it more difficult for sound to pass through.
However, all glass will allow some level of sound to pass through, regardless of how thick the pane is.
This helps explain why an acoustic window system will use two different thicknesses for the glazing, plus an air gap and laminate to help combat any noise pollution.
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Is acoustic glass more expensive than triple glazing?
The simple answer is that acoustic glass is more expensive than triple glazing because it has been treated with a special laminate that helps deal with noise intrusion.
A good quality noise reduction window will cost more money but if you want to reduce noise pollution, then this could be a good investment to consider.
That’s because you will help boost the appeal and value of your property when you come to sell.
As an alternative, you could consider installing secondary glazing which will mean adding a pane of glass without having to install new frames or windows.
The average price for this is around £400 for every window but if your frames are old, then you may find that installing secondary glazing may not be possible.
The price of soundproof acoustic windows can range from £900 to nearly £2,000 for each one.
And if you opt for stylish soundproof acoustic sash windows, you could be looking at a bill of between £1,400 to nearly £5,000 for each window.
What is the sound transmission class rating?
The sound transmission class (STC) rating is a way to compare soundproof windows.
Essentially, the pricier acoustic windows will have a higher STC rating but will be effective in blocking out unwanted noise.
The rating is used to measure sound insulation in the wall assembly so there will be a figure for the materials used for doors, floors and ceilings, and interior partitions.
Understanding the STC rating – and how it impacts the price of acoustic windows – is probably the most important aspect of considering whether to install acoustic windows or not.
However, there’s no point in compromising on the STC figure to save money if you live by a busy, noisy road, for example, when triple glazing may offer a more cost-effective solution if there is a level of noise you are happy to put up with.
Is acoustic glass better than triple glazing?
There is a lot of debate about which is better: acoustic glass vs triple glazing? As we have seen, acoustic glass is better at reducing noise levels than double- and single-glazed windows, but – depending on the noise levels – it might not be as effective as triple glazing.
In addition, triple glazing offers better thermal qualities and will help lower your home’s heating bills.
A lot depends on your budget, where you live and the type of noise you want to block out because acoustic glazing may be worth the extra cost.
If you want to reduce noise and benefit from cheaper heating bills, then triple glazing is certainly worth considering.
Whichever route you consider, it’s always worth speaking to at least one glazing company about their window products and how they can improve the noise pollution levels in your home.