Living in a home with constant ambient noise from the street, trains or cars, or other sources such as factories can ruin even the most idyllic of locations. You’re probably wondering if new windows can help you to reduce noise, and if so, by how much.
We’ve put together a complete guide to soundproof windows to help you learn about how soundproof windows work, what they can do for you, and how much they are likely to cost.
- Double and triple glazing can reduce sound pollution significantly over single pane glass
- Taking extra measures such as using laminated glass and insulated frames can significantly increase soundproofing.
- Secondary glazing is the most efficient way to soundproof windows
- Soundproof windows will typically range from about £400- £1,200 per for secondary glazing.
How Much Can You Reduce Noise Levels in Your Home
Unfortunately, soundproofing a home is rarely simple. Because acoustic sound varies a great deal, your windows must be equipped to handle different types of sound to truly block out noise.
For example, consider the following chart:
|Sound Source||Sound Pressure Level (Lp dB SPL)||Sound Pressure (p N/m2 = Pa)||Sound Intensity (I W/m2)|
|Jet airplane (50m distance)||140||200||100|
|Power Saw (1M)||110||6.3||0.1|
|Large truck (10m)||90||0.63||0.001|
|Traffic Noises (5m)||80||0.2||0.0001|
You can probably easily imagine the noise level of a jet (which is painful to the ears) and that of a conversation and measure volumes accordingly. Ideally, you can picture some of the other sounds as well, which will help to give you a better understanding of how sound must be blocked out from your home.
The higher the pressure and the more intense the sound, the more difficult it is to block out. For example, an item like a power saw has a sound level just 30 decibels below that of the jet airplane, but while you could likely block out a power saw or even not hear it at all by going inside of another room, the jet would be audible, even with the best windows.
Most people prefer a noise level of about 30-35 decibels or less in their homes. If you install regular windows, you will likely see the following noise reduction in your home.
|Sound Level (dB)||Single Glazing (-20dB)||Double Glazing (-30dB)||Triple Glazing (-34dB)||Sealed Secondary Glazing (-34dB)||Double Glazing with Sealed Unit 1 15cm Cavity (-44dB)|
|80 (very loud street noise within 5 meters of your window)||60 dB||50dB||46dB||46dB||36dB|
|70 (typical street noise at 5m)||50 dB||40 dB||36dB||36dB||26dB|
|40||20 dB||10dB||6dB||6dB||0 exterior noise|
In short, blocking out sound depends on the window, the measures you take to soundproof, and the noise intensity and level. From an 80-dB sound level, the only windows capable of bringing noise levels down to acceptable interior levels are those with large air cavities and sealing designed to stop noise. However, the effectiveness of any windows you install will depend on exact noise levels.
What’s Important for Soundproof Windows
Soundproof windows have to stop multiple noise frequencies, noises at different decibel levels, and different pitches. This means that soundproof windows ideally feature multiple layers of glass in different thicknesses, an air or gas cavity, and insulated frames to stop noise transfer.
Glass Thickness – Most double and triple glazing features panes that are the same thickness. This can reduce noise to some extent, but if you are unlucky, the dual panes of glass may resonate and amplify the noise. Ideally, your glass will be as thick as possible, with one pane slightly thicker than another. This will mean requesting special accommodations from your installer, and will cost more, but will greatly reduce noise levels.
Insulated Frames – Most quality installers offer insulated uPVC or aluminum frames or solid wood frames, which can reduce noise. Regular uPVC and aluminum frames are hollow on the inside, which provides less of a barrier to sound. Paying for insulated frames will reduce sound transference and will reduce heating and cooling loss at the same time.
Air Cavities or Inert Gas Cavities – Most double glazing features an air cavity or inert gas cavity between the panes. This cavity can be crucial in stopping sound. Choosing a larger cavity of 50mm to 200mm will block more sound. However, argon gas offers little advantages over air cavities.
|Frequency (Hz)||No Cavity||50mm Cavity||200mm Cavity|
The higher the frequency of the sound, the better glass and air cavities are at stopping the noise.
Sealing – Sealing windows will reduce sound pollution, especially if existing frames are old, seals are broken, or the new seals are specifically designed to stop sound.
Types of Soundproof Windows
You can choose multiple types of soundproof windows, depending on your needs and budget.
Double Glazing Soundproofing
Double glazing makes excellent soundproofing providing your ambient noise levels are either typically below 65 dB or you take additional soundproofing measures to ensure that your windows can reduce noise levels.
Double glazing sandwiches a cavity of air or inert gas between two panes of glass, which works as a barrier to stop heat, cold, and noise. Standard glazing reduces noise by about 30 decibels, which will reduce street noise if you are about 10 meters from the street, but not if you are closer.
Triple Glazing Soundproofing
Triple glazing is often thought to be significantly better at reducing sound, but you can typically expect an additional 4 decibel reduction with the extra pane of glass. This is because most triple glazing uses thinner panes and smaller air cushions, with panes that are all the same size.
However, like double glazing, you can purchase triple glazing so that it offers increased sound resistance. Unfortunately, the sound reduction improvement over double glazing often isn’t enough to justify the added expense, unless cost isn’t a concern.
Secondary glazing is considered to be the best method of soundproofing windows because it enables you to add a secondary layer of glass in another thickness with an insulated air gap to stop noise. More importantly for most, this soundproofing measure is more affordable than purchasing new soundproof windows.
Laminated glass is specifically coated to help stop noise transfer. In most cases, glass is laminated with Polyvinyl Butyral (PVB), which is a type of plastic. Here, the PVB coating works to stop sound by adding yet another layer to your sound barrier, preventing resonance and sound amplification. This glass is typically sold as safety glass or acoustic glass. A laminated glass pane with a 100-mm sound gap can reduce noise levels by as much as 35 dB when added as secondary glazing to an existing single pane window, for a total reduction of an average of 45 dB or more.
How Much Do Soundproof Windows Cost?
Now that you know how soundproof windows work, you’re probably mostly concerned with cost. Installing new soundproof windows can be extremely expensive, because additional glazing, choosing different glazing thicknesses, insulated frames, and sealing all cost extra.
However, the exact cost of soundproof windows depends on what you want, what your installer has, as well as your frame and window style choices.
- Secondary glazing will range from £400 to over £1,200
- Soundproof casement windows typically start out at about £750 per window
- A soundproof sash window will likely cost £1,200 or more per window.
Getting a Good Deal on Soundproof Windows
Soundproof windows are expensive, but they are an investment in your home. Not only will they make your house nicer to live in, they will increase the value and saleability of your property should you choose to move. However, you shouldn’t have to pay the maximum price to soundproof your home.
In most cases, your best option is to choose secondary glazing, which offers quality soundproofing without requiring you to install new windows, pay for new frames, or invest upwards of £1,200 per window. However, if you currently have very old frames or very old single pane glass (25 years or older), buying new replacement soundproof windows will be your best option.
- Know what you need. If you want to reduce audible sound from 80 dB to 30, you don’t need to pay for a window that can reduce noise by 58dB
- Compare your options. Window installation is competitive and you can get a better deal on specialty solutions like acoustic glass and soundproof windows by directly comparing quotes.
- Get an inspection. Your window installers may be able to help you to make the best choices for your home based on the SRI (Sound Reduction Index) rating of your window options.
If you’re ready to move forward with installing soundproof windows, we can help. Use our free comparison tool to find the top quotes from local installers in your area. We will collect the lowest quotes for your windows from top installers and forward you the best three, so you can save on your soundproof windows.