Sound protection for windows

If a building is located close to a heavily trafficked road it is quickly exposed to noise pollution. Every car, truck or even tram produces a background noise that can significantly impair your quality of life. Even in rural areas it is often necessary to turn to acoustical windows. If a railway line passes the building or if a house is on the approach flight path to an airport, sound insulation is particularly important.

Noise protection classes for windows

People are very sensitive to noise. Even when we are asleep the human ear remains a sensitive sensory organ and we should therefore avoid being exposed to noise levels in excess of 25 dB at night. Although it is easy to make this statement, it is a lot more difficult to implement in practice. Heavily trafficked roads often have noise levels of around 70 dB and even purely residential areas frequently reach noise levels of over 40 dB. Special acoustical windows are able to reduce the noise level. It is, however, not only the properties of the window that play a major role in noise abatement – noise can also penetrate through gaps that occur at the time the window is installed. Effective sound insulation is therefore equally dependent on sealing the windows during the installation process using the appropriate glazing tape, etc.

The importance awarded to noise control is demonstrated by DIN 4109. This standard sets out sound insulation requirements for windows and doors and stipulates the minimum standards to be observed by builders. Altogether, there are six noise protection classes for windows. The principle here is that an acoustical window must reduce noise pollution by a defined amount.

  • Noise protection class 1: the thickness of the glazing in these windows is 4 millimetres. The DIN standard requires that an acoustical window in this class reduces noise pollution by 25 - 29 decibels. This version concerns windows with single glazing.
  • Noise protection class 2: to achieve sound insulation of 30 - 34 decibels, the acoustical window has two 4-millimetre thick glazing panes. Between the individual panes is an air gap approximately 16 mm thick filled with argon or another gas.
  • Noise protection class 3: these windows also feature two glazing panes. However, in this case, the outer pane is 6 mm thick, and the inner pane is 4 mm thick. The space between them is filled with a gas mixture. These windows achieve a sound insulation of 35 - 39 decibels.
  • Noise protection class 4: to achieve a sound insulation of 40 - 44 decibels, this acoustical window must have an outer glazing thickness of 9 millimetres with an inner glazing thickness of 6 millimetres. In addition to the gas filling, a PVC foil is also applied to further reduce noise pollution significantly.
    System Arcade – Technical Specifications
  • Noise protection class 5: with a sound insulation of 45 - 49 decibels, this noise protection class is particularly well suited to factory buildings and other very loud environments. The two panes have a thickness of 11.5 and 9.5 millimetres and in addition they are cladded with foil. The gap between the panes is 20 millimetres wide.
    System Eforte – Technical Specifications
    System Prestige – Technical Specifications
  • Noise protection class 6: These acoustical windows are 'box' windows and provide a noise reduction of over 50 decibels.

Sound protection can be achieved with many types of windows

There are many kinds of windows. They come in different shapes and sizes and must withstand various stresses. Today it is possible to design practically any window as an acoustical window. Even roof windows and skylights can serve as acoustical windows and meet the requirements of one of the noise protection classes. The decision about which window to choose for a building depends, of course, on the ambient noise level. However, the sensitivity of the residents to noise also plays an important role. People who are very sensitive to noise should ensure that they install acoustical windows during the building or refurbishment process.

Why noise protection is so important

Today it is practically impossible to completely avoid noise pollution. We are almost constantly surrounded by commotion and noise that we mostly just ignore. However, being under constant pressure from noise not only has a negative impact on our hearing, it also has a significant effect on us physically which can lead to a deterioration in our health and can be difficult to determine. Who would think that heart disease or high blood pressure could be caused by exposure to excessive noise?

Noise control not only makes an important contribution to protecting people's health in the private sector, but employers also have to provide their employees with the appropriate equipment to protect their hearing. Besides protecting those employees employed in the production process, manufacturing companies also have to protect those working in administration. If offices are located inside the production area or close to it, it has proven to be worthwhile installing acoustical windows. Reduced noise pollution using increased sound insulation creates a relaxed working atmosphere that not only reduces the number of sick days taken but also increases productivity significantly.

Funding opportunities for acoustical windows

The importance attached to acoustical window installation is underlined by the various funding opportunities available. Residents can benefit from funding to install acoustical windows, particularly in densely populated areas. Homeowners can ask their local authority if they qualify for funding. Many towns now have maps marked with areas in need of protection. Funding is, however, partially restricted to individual parts of the home. Normally, children’s rooms, living rooms and bedrooms are considered worthy of protection. Depending on your town and region, you may be eligible for a subsidy of about 75 percent for the installation of noise protection class 4 acoustical windows.

Acoustical windows can, of course, be retrofitted. If existing windows are to be replaced and upgraded to meet the new Energy Saving Regulation, people should not only take into consideration the thermal insulation class, but also demand enhanced sound insulation.