Soundproof windows

With heroal soundproof windows, you can reduce the sound level by up to 48 decibels (dB) and make a huge improvement to your quality of living.

Soundproof windows

Optimum noise and sound insulation for windows

Do you live on a busy road or near a railway line? Then you know how irritating it can be when noise gets into your house day after day. With heroal soundproof windows, you can reduce the sound level by up to 48 decibels (dB) and make a huge improvement to your quality of living. In addition to the thickness and mass of the window panes, the window frame and the proper installation of soundproof windows are important factors in effectively reducing the noise level. The principle is that the window should absorb the sound without passing it on to the living space. We will show you when an acoustic window is recommended, how high the sound reduction index and the sound insulation class should be and which properties make a good soundproof window.

What‘s so special about heroal soundproof windows?

100 % foam-filled

The profiles of heroal windows are 100 % foam-filled. The special filling process has been developed by heroal, and provides for ideal sound insulation levels, also for especially slim frames.

Soudproofing up to class 5

Aluminium windows by heroal achieve sound insulation levels of up to 48 dB. This meets the requirements of sound insulation class 5, according to German industry norm DIN 4109. The sound insulation class is the result of the individual combination of frame profile, thickness of glazing and professional installation.

Tailor-made soundproofing

Thanks to the modular design of heroal windows, you can adapt your windows to the sound insulation class you need. You can choose from various sealants and sealing zone designs, face widths and foam fillings.

Components of heroal soundproof windows

Many factors influence the functionality and performance of an acoustic window. The glass thickness, the space between the panes, the material of the window frame, the construction and the installation of an soundproof window all play an important role in ensuring effective sound insulation.

Laminated glass panes

Laminated glass panes - Laminated glass panes have an elastic interlayer between two or more layers of glass and increase the noise insulation of windows.

Various pane thicknesses

Various pane thicknesses - Sound-proof windows have a different thickness of glass on the panes. The higher the difference in thickness of the inside and outside pane, the higher the noise insulation.

Air gap

Air gap - The air gap between the individual panes has to be wide enough, so that the vibrations of the outside pane are not passed to the inside pane. Special materials for the air gap, such as PVB films or casting resins, absorb sound and only pass it on at reduced values.


Mass - The higher the mass of a pane, the less it vibrates. More sound waves hitting the pane can be reflected. Therefore, thicker and hence heavier panes generally reach a higher noise insulation value.

Installation according to certified installation manual

Installation according to certified installation manual - If sound-proof windows are not professionally installed, their noise insulation values may easily decrease by some decibels. Our heroal specialised partners make sure that your sound-proof windows are professionally customized and sealed in order to reach optimal sound and noise insulation values.

Material for window frames and sashes

Material for window frames and sashes - The material aluminium stands out for its insulation values and is perfectly suited for sound-proof windows.

Design of window frames and sashes

Design of window frames and sashes - The window frame is an essential part of efficient sound insulation. heroal window frames are foam-filled. Therefore, the window frame reflects and absorbs sound.

Our solutions for noise insulation up to 49 dB

Which sound insulation class do you need?

The German Sound Insulation Regulation DIN 4109 defines minimum requirements for sound insulation as well as six sound insulation classes to determine the acoustic properties of windows. It is intended for use in comparing various sound insulation measures. The sound insulation classes are determined by the sound reduction index Rw in dB (decibels). The sound reduction index describes the sound insulation of an installed soundproof window. In order to be able to estimate which sound insulation class is required for effective sound insulation, the table below shows sound insulation classes for specific traffic volumes and distances to the road.

Soundproofing class Sound reduction index (Rw) Traffic density Distance of house to the road
1 25 - 29 10 - 50 vehicles/h > 35 m
2 30 - 34 10 - 50 vehicles/h 25 - 35 m
3 35 - 39 50 - 200 vehicles/h 25 - 35 m
4 40 - 44 1,000 - 3,000 vehicles/h 100 - 300 m
5 45 - 49 1,000 - 3,000 vehicles/h 30 - 100 m
6 ≥ 50 3,000 - 5,000 vehicles/h < 100 m

Testing soundproof windows

Comparison of windows with and without sound insulation

Test the noise reduction of the sound insulation classes that heroal windows can provide. You can use the slider to simulate the different sound insulation classes. Please turn on your speakers – with sound insulation class 0 the noise should be perceived as unpleasant.


Current sound insualtion class 0

Meaning of sound insulation class

The sound pressure level is reduced by 25 - 29 dB(A), the noise protection is very low.

The sound pressure level is reduced by 30 - 34 dB(A), which results in low noise protection.

The sound pressure level is reduced by 35 - 39 dB(A), which results in moderate noise protection.

The sound pressure level is reduced by 40 - 44 dB(A), the noise protection is perceived as good.

Very good noise protection is achieved by reducing the sound pressure level by 44 - 49 dB(A).

Extremely high noise protection by reducing the sound pressure level by 50 dB(A) or more.

Note: The actual sound insukation may differ from the audio examples.


  • Where can I buy heroal soundproof windows?

    A professional installation is essential for your windows to provide the required sound insulation. heroal soundproof windows are exclusively available from heroal specialist partners. The windows are manufactured individually for you and adapted to every installation situation. Please use our heroal specialist partner search to find a suitable fabricator in your area, and ask for advice in order to get your perfect sound insulation.

    Find a specialist partner now >

  • Who installs heroal soundproof windows?

    Proper installation of acoustic windows has a considerable influence on their functionality. Our specialist partners will give you expert advice before you buy your acoustic windows in order to find the right window for you. With professional installation, our specialist partners ensure that your soundproof windows are precisely fitted and sealed to achieve optimum sound and noise insulation values. Use our partner search tool now to search through 3,500 heroal professionals worldwide and find a partner in your area to ensure that your acoustic windows are properly installed.

    Find a specialist partner now >

  • When are soundproof windows needed?

    Ongoing noise is not only irritating, it can also affect your health. For adults, ongoing noise can have an impact on the cardiovascular system. For children, an ongoing high noise level has a significant impact on brain performance. Especially for people who live in a big city, on a busy road or near an airport, it is advisable to protect yourself against noise with acoustic windows. There are no general rules for the volume level that makes an soundproof window necessary. Noise is perceived subjectively, and each person feels a slightly different noise level to be disturbing. In general, however, a level of 55 decibels (dB) or higher makes it difficult to concentrate. Starting at 65-70 dB, there is an increased cardiovascular risk; and starting at 85 dB permanent hearing damage can occur.

  • When do I need which sound insulation class?

    However, the required sound insulation for a window also depends on the respective function of the living space. The following values can be used for orientation. During rush hours, the noise level should not exceed 25 dB in a bedroom, when the windows are open, 35 dB in a living room and 35 to 50 dB in a study. When it is time to start making plans for the installation of acoustic windows, the required soundproofing class should be determined in advance with a measuring device. A measurement is best made when the noise level is at its highest. If the noise reaches a value of less than 25 dB in the bedroom, a simple class 1 soundproof window with a sound insulation value of 25 - 29 dB is sufficient. However, if you measure a value of 43 dB, for example, you should opt for a class 4 soundproof window, which provides a sound insulation value of around 40 to 44 dB.

    To determine the right sound insulation class for you, it is best to contact an experienced specialist adviser. With our partner search tool, you can find a heroal professional in your area who can determine the sound insulation class you need and install the right acoustic window for you. Find out now about heroal specialist partners near you.

    Find a specialist partner now >


Advantages of heroal soundproof windows

Depending on the requirements, heroal soundproof windows can be upgraded as high as sound insulation class 5, which allows them to meet the highest sound insulation demands. Try them out for yourself. We would be happy to give you more information about the right acoustic window for your needs. Give us a call, visit our specialist partners and let us inspire you.

  • Certified sound insulation
  • Sound insulation classes 1 to 5
  • Tested quality, made in Germany
  • Robust and easy to clean
  • Sustainable and environmentally friendly

Find the right heroal specialist

1 Create a request with just a few clicks
2 We'll find the right heroal specialist for you
3 We'll send you the contact details

Click here to search for a specialist partner

Search >

Thanks for your interest in heroal products

We will gladly send you the contact details of the matching heroal specialist in your area. To do this, we need your name, zip code, city and email address. We’ll also happily contact you by phone. In order to find the right specialist for your specific requirements, please specify which products you are interested in.

Personal Details

Please fill out this field.
Please fill out this field.
Please fill out this field.
Please fill out this field.
Please fill out this field.
Please fill out this field.

I'm interested in:

Please fill out this field.

Further reading for your interest

Your advantages with heroal

The heroal promise

When it comes to how we live and work, the most important thing is having choices. heroal knows that. As a family-run company with more than 140 years of experience, we believe that when it comes to quality, there are no compromises. That is why our products give you a way to create ideal solutions for nearly any requirement. As a technology leader, we believe that quality means more efficiency, more reliability and more performance – solutions that are "SIMPLY. BETTER."

  • over 3,500 specialist partners worldwide
  • products with tested quality
  • family-run company with a long tradition
  • made in Germany
  • personalised design
  • comprehensive range of services
  • superior technical solutions