Charmille Schuman 1

Organic optimises acoustics in new Charmille and Schuman schools

Acoustic improvement in the sports hall

Architectural office B612 designed the plan for the realisation of a new ecological neighbourhood in Sint-Lambrechts-Woluwe. The plan also included the refurbishment of two schools - La Charmille (special education) and the Parc Schuman nursery and primary school. In order to make the buildings comfortable, pedagogical and functional, acoustics are very important. Not a superfluous luxury, since it can be quite noisy in the schools and the accompanying sports halls...


In sports halls and gymnasia, noise quickly becomes a nuisance. Acoustic solutions were therefore provided for the semi-underground sports hall of Parc Schuman and for the upper gymnastics hall of the Charmille school. The architects' choice fell on Organic Twin panels - good for an area of around 1,200 m² (400 m² for La Charmille and 800 m² for Schuman). We chose these panels not only because they guarantee acoustic comfort, but also because the wood wool panels are very easy to install, impact resistant and offer a beautiful aesthetic that matches the concrete elements, says Olivier Mathieu (architect, B612 Architectural Office).

Wood wool panels with rock wool

The acoustic ceiling panels installed by MCO consist of a layer of high-density rock wool and two outer layers of thin wood wool (1 mm thick). These sandwich panels allow for sound absorption of around 90% (average value) while taking up minimum space, explains Adrien Tardy (Business Development Manager, Knauf). They had already been painted white and finished with faceted edges at the factory when they arrived at the construction site. The wood wool panels were then anchored directly to the concrete.

Sizeable challenge

Although this seemed like an easy task, the installation of the acoustic panels was a real challenge. Adrien Tardy: In the two sports halls, the high windows and other elements (such as the cords hanging from the ceiling) made it impossible to work with a plenum. The challenge here was to achieve sufficient sound absorption even without a plenum. Since the perforated products normally used did not suffice, 35 mm thick Organic Twin panels were chosen.

Moreover, in the sports halls we had to reconcile two conflicting requirements: impact resistance and sound absorption. The latter can prove problematic as all sorts of different sound frequencies are generated in such rooms, ranging from low frequencies of less than 1000 Hz (e.g. balls hitting the floor) to high frequencies that can reach 4000 or 5000 Hz (e.g. children screaming).

The advantage of the Organic Twin

The advantage of the Organic Twin panels is that the wood-fibre structure dampens sound efficiently and in a relatively homogenous manner, and this for all audible frequencies. Textile products or stone wool are highly suitable for absorbing sound above 1000 Hz, but not for lower frequencies. The Organic Twin panels guarantee excellent acoustics because they correct all frequencies in an almost identical way.

Organic Twin

Product used?

The Organic Twin wood wool panel was used for this wonderful project. This panel offers a very good acoustic performance. The wood used for the wood wool panels comes from PEFC-certified forests near the factory.

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