building acoustics
Klas Hagberg
Acouwood partnership with Kuster and Partner
Acouwood partnership with Kuster and Partner

building acoustics

Acouwood partnership with Kuster and Partner

Acouwood AB and Kuster + Partner AG (www.kusterpartner.ch) have been cooperating closely for some time. It is about the exchange of knowledge such as methods, research & development of essential knowledge and tools, as well as the refinement of skills. Kuster&Partner is a leading consulting company in Switzerland in the areas of building physics, including acoustics. Together we can now offer customers and architects' offices the bundled expertise from more than 30 years of timber construction from one single source, from the design to quality assurance during construction, in order to optimize the acoustic quality and energy performance. High sustainability goals and demands on a comfortable room climate combined with excellent acoustics are at the forefront of our advice. It means that we (Acouwood) broaden our source of knowledge regarding indoor climate (energy and humidity, for example) but also increase our presence in the center of Europe.

The cooperation enables us to accompany national and international projects in several languages and carry out energy and acoustic calculations and measurements at the highest level to help design optimal future buildings in terms of sustainability.

Combined services in the field of timber construction

In the association, we have a whole range of options and tools at our disposal for advising on optimal and sustainable buildings:

  • Building simulations for rooms or entire buildings to simulate various parameters such as temperature, humidity, or light

  • Simulations for the noise protection of roads, railways, airports, or industrial plants

  • Specialized tools and measurement methods for forecasting building acoustics down to 20 Hz

  • Experienced practitioners for the development and assessment of details in massive wood and lightweight construction

  • Extensive measuring equipment park to carry out the latest measurements available on the market. Especially in the field of building acoustics, we are not only able to carry out normal measurements according to the standard but also to check flanking sound (intensity and Kij measurements)

  • With Kuster&Partner test laboratories, we can develop lightweight components and building products such as windows/doors and measure them on a project basis.

We can offer our services in the following languages: German, English, Swedish, French.

 

If you have any questions regarding timber structures, please contact Klas Hagberg (Swedish, English, klas.hagberg@acouwood.com), Mr Thomas Kuster (German, English, thomas.kuster@kusterpartner.ch), Marco Kuster (German, English, marco.kuster@kusterpartner.ch) or Dr. Delphine Bard (French,English, delphine.bard @kusterpartner.ch).

*Cinema picture was kindly shared with us by Schwab Systems SA

Sound insulation in 3D

Sound insulation in 3D

One of the most challenging aspects of building acoustics is that sound insulation and sound transmission paths are present in all three dimensions, when flanking transmission is included. If you have two rooms next to each other that requires a certain sound reduction index R´w in dB between them, the first thing that comes to mind is the directly separating construction, i.e. the wall between them or the floor structure. Most of the time, you will be correct, as this is often the most important transmission path. Hence, it is easy to miss that sound transmission occurs in many other places in a real building, which are not obvious at all when looking at a 2D drawing.

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Flanking transmission in CLT dwellings – How to design a proper ceiling

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Flanking transmission in CLT dwellings – How to design a proper ceiling

A common way to construct Cross Laminated Timber (CLT) dwellings is to mount the floor slabs continuous over several apartments, thereby reducing the number of CLT elements and work time with the crane on site. There are some crucial acoustic factors to consider if you are thinking about this route. CLT is sensitive to flanking transmission in the middle frequency range from about 125-160 Hz and upwards. If CLT elements are mounted between apartments and are exposed within the dwelling, the resulting sound insulation will not fulfill Swedish requirements. The resulting sound insulation R´w will likely be in the 40-50 dB range and not 52 dB as it should be. A common way to solve this issue is to install a resilient ceiling, and the solution can be optimized in different ways depending on the rest of the structure.

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Vertical flanking sound transmission in CLT dwellings

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Vertical flanking sound transmission in CLT dwellings

Dwellings with Cross Laminated Timber (CLT) have become very popular lately. When designing a multi-family dwelling in CLT there are some critical factors to consider with regards to acoustics and sound insulation. A characteristic property of CLT is that it is very sensitive to flanking transmission i.e. sound transmission between two rooms another path than through the directly separating partition. What this means in practice, is that whatever you do, do NOT mount CLT elements that are continuous between two dwellings. That is a recipe for disaster. It might work in premises or between rooms with lower requirements, but in dwellings it is a big NO-NO. So, what solutions are there?