Making acoustics a central part of a building’s design
Whether it’s a car alarm in the middle of the night, airplanes flying overhead, a crying baby in the flat next door, or construction happening across the street – for many of us, there’s nothing more annoying than noise. “More than just being annoying, noise can affect our concentration, mood, and even health and well-being,” explains Edwin Reynders, a professor of Civil Engineering at KU Leuven. With the support of the EU-funded VirBAcous project, Reynders is developing engineering methods for the design of buildings with good sound insulation – a task that is more challenging than it ‘sounds’.
Looking at the entire building system
According to Reynders, the challenge is that, unlike thermal insulation, sound insulation is not delivered through a single layer of material but depends on the building system in its entirety. “Sound travels not only through the common wall with a neighbouring room, but also through flanking paths such as a continuous ceiling,” he says. “That’s why sound insulation must include all elements of the walls and floors, even how they are connected.” As a result, acoustic requirements do not naturally align with a building’s structural and thermal requirements. “Acoustics cannot be an afterthought, it must be a central part of a building’s design,” adds Reynders. To help, the VirBAcous project, which received support from the European Research Council, has developed dedicated computational tools that the construction sector can use to design a quieter building.
Designing tailored building components
Striking the right balance between accuracy and computational efficiency, engineers, architects and other building professionals can use the project’s numerical modelling tools to design tailored building components such as walls, floors and junctions with optimised sound insulation properties. For example, researchers used the software to optimise the cross-sectional shape of flexible metal studs in double-leaf plasterboard walls. They were then able to demonstrate that these studs, which use a similar amount of material as their commercially available counterparts, offer a significant increase in sound insulation. “The beauty of the VirBAcous tools is that they allow one to design and test the sound insulation and absorption properties of new, complex building components virtually – all from a laptop – which not only streamlines the design process, but also makes it considerably faster and cheaper than repeated prototype testing,” notes Reynders. “If all goes well, testing a prototype of the final design to confirm its performance is sufficient.”
Sound insulation prediction software
While the VirBAcous solution is an important step towards making buildings quieter, there’s still plenty of work to be done. “There is a clear need in the construction sector for dedicated sound insulation prediction software that is sufficiently fast and accurate for design and optimisation,” remarks Reynders. “The numerical tools developed in this project are the basis for such software, but they must be complemented with translational research to bridge the gap with engineering practice.” The project team is currently further developing and refining its tools so that engineers can use them to develop solutions for flanking sound transmission in cross-laminated timber (CLT) buildings. CLT is a booming construction material with important ecological and economic benefits, yet its light weight makes it acoustically very challenging. “By increasing their acoustic performance, VirBAcous can help in the breakthrough of new, more sustainable construction methods,” concludes Reynders.
Keywords
VirBAcous, noise, acoustics, computational tools, construction sector, building, engineering, sound insulation
