Did you know that noise can have the same impact on your health as air pollution? If your home is near a busy street, not only should you be concerned about smog, but excessive noise levels can negatively affect your quality of life.

But before you give up on buying your dream property or start thinking about moving – pause for a moment. The right choice of windows is the solution to the potential problem of excessive noise. Good quality window frames can improve the acoustic comfort of your home by insulating it from annoying outside sounds.

What is acoustics?

Acoustics is the science of sound, its generation, propagation and reception by humans. In the context of construction, acoustic insulation, i.e. the ability of a structure to dampen noise from the external environment, is a particularly important issue.

All sound, regardless of its origin, is the result of acoustic waves carrying energy. The waves can penetrate the building envelope – walls, roofs or windows. In this way, they affect the noise level inside. Effective insulation aims to minimise this phenomenon.

The acoustic insulation of windows is particularly important for houses located near expressways, airports, railway lines or in densely built-up urban areas. In such places, daily exposure to noise can have a negative impact on health and, in the long term, lead to concentration problems, sleep disturbances and even chronic stress.

Acoustic properties of windows

Since you want the right level of silence, you need to pay attention to a few technical issues that are related to the window design.

The acoustic properties of windows are influenced by many factors – the construction of the glass, type of glazing, type of frame, sealing system or installation technology. Lack of this awareness can lead to the purchase of windows that do not provide sufficient noise protection.

Before deciding on a particular model, it is important to understand how all the parameters affect acoustic comfort. You will find a discussion of the most important elements below – with this knowledge you will make an informed decision.

Window construction and acoustic properties

The construction of a window (i.e. its shape, size and type of glazing) is of great importance in terms of sound insulation. Windows consist of several glass panes. In between, there are layers of gasses to improve insulation. Different glazing thicknesses are often used in windows with parameters relating to low sound transmission. This makes it possible to differentiate the frequencies of the sounds which are effectively attenuated.

Why is this important? Sound waves, which have different lengths, affect building materials differently. The use of glazing of different thicknesses allows a wide range of noises – from low frequencies (e.g. car noise) to higher tones (e.g. sounds of sirens, horns) – to be dampened more effectively. What is more, the use of double-glazed units reduces the risk of vibrations that could transmit sound into the interior.

Sound insulation of the frame

Window frames can be made from a variety of materials – wood, PVC, aluminium or composite. Each of these materials has different sound-absorbing properties and affects the final level of permeability in a different way.

Timber frames are considered to be among the best in terms of sound insulation, as timber has natural sound dampening properties. Their big disadvantage is the need for maintenance. For some of us, price is also a factor, which in this case is the highest of all available options.

However, we have aluminium frames – durable, lightweight and, although often considered less effective in terms of sound insulation, this is an issue that the window joinery industry is very good at dealing with. Aluminium frames use additional thermal insulation fillings. Such models, when compared with wooden joinery, can provide us with similar parameters – but decidedly more economical.

The shape of the frame and the way it is assembled also have an impact on noise reduction. Wider profiles and multi-chamber systems that retain air inside the frame effectively reduce sound transmission. It is therefore worth paying attention to the construction details of the window and the additional insulation layers in the frame.

Seals – the role of sealing in the context of acoustic performance

Another element is the gaskets, which provide a seal between the frame and the glass. Gaskets have a particularly important task – they block the passage of sound through small gaps that could occur as a result of inaccurate installation or material wear. Choosing the right gaskets, usually made of flexible materials, can effectively increase the sound insulation of a window.

However, it is worth remembering that seals wear out over time and lose their properties. Therefore, regular maintenance, cleaning and replacing them are essential steps in order to maintain the performance values promised by the manufacturer.

Pay attention to what seals are used in the windows you are considering. They should be easy to maintain and weatherproof. Seals that are too hard can lose their elasticity over time – this will lead to leaks and therefore reduce sound insulation levels.

List of parameters and their values that indicate good sound insulation

If you want quiet and acoustic comfort in your home, you need to pay attention to the technical parameters of your windows. Each of them has a significant impact on the final level of noise attenuation, so it is worth carefully analysing the technical specifications of the chosen model before you buy.

• Rw (reduced sound insulation coefficient) – the most important parameter which determines a window’s ability to dampen noise. The higher the Rw value, the better the insulation. For windows with improved acoustic properties, the Rw value should be at least 40-45 dB.
• C and Ctr (noise spectrum corrections) – additional indicators that take into account different types of noise – road noise (Ctr) or high frequency noise (C). For buildings located next to roads, it is advisable to choose windows with high Ctr values, which better attenuate low-frequency noise.
• Glazing thickness – triple-glazed windows with different glazing thicknesses (e.g. 4, 6 and 8 mm) provide better sound insulation.
• Distance between panes – the optimum distance between panes is between 12 and 16 mm. Too little distance reduces sound insulation, while too much distance can lead to condensation problems inside the glass.
• Gas in the glazing cavity – glazing filled with noble gas (argon or krypton) has better properties than glazing filled with air.