In contrast to traditional concrete and steel structures, mass timber buildings offer numerous benefits. Their reduced weight improves seismic resilience, and the use of standardized fabrication allows for more efficient transport. These structures are assembled on-site, which shortens construction timelines and lowers labor costs. Furthermore, mass timber is both recyclable and sustainable, supporting environmentally conscious construction practices.
However, one aspect of mass timber buildings that is still being examined and tested is acoustics. Being lightweight, mass timber structures face challenges in acoustic performance, but there are numerous proven ways to prevent sound transfer through the structure and create good sound comfort for users.
Good acoustic design begins in the earliest phases of a building’s planning, with strategic zoning that separates areas based on expected sound and vibration levels. In mixed-use buildings, spaces such as retail stores, offices, and gyms are typically located on the ground floor or lower levels to minimize noise transfer to residential areas above. In hotels, it is especially important to isolate guest rooms from noisier zones like conference rooms, event halls, and mechanical spaces. Once zoning is established, the next step involves designing façades, floors, walls, and ceilings to effectively block or absorb unwanted sound transmission through the structure.
Walls
There are two main ways to enhancing the soundproofing of partition walls: increasing the mass of the wall and structural discontinuity. While massive walls—typically made of brick or concrete—rely on mass to block sound, mass timber construction generally employs the latter method. This involves layering additional insulation materials, applying covering boards, and incorporating air gaps to act as buffers against sound transmission.
Various installations (plumbing, electricity, wiring etc.) placed in a wall can weaken its sound insulation power due to the holes. In this case, it is recommended to create double walls (one made of gypsum boards with optimal soundproof performance) in order to isolate both rooms from sound transfer through holes.
Floors
To enhance acoustic performance, the thickness of Cross Laminated Timber (CLT) panels has been increased to 245mm, making them more massive and effective at blocking sound. In the broader floor assembly, a combination of strategies is employed to improve sound insulation. One approach involves increasing the mass of the floor panel by adding a concrete layer that serves as a base for the final floor covering. Beneath this base, acoustic mats are often installed to absorb vibrations. Additional decoupling between the CLT panel and the floor covering introduces an air layer that further dampens sound transmission. Along the perimeter of the floor, intentional air gaps can be filled with isolation strips to prevent sound bridging. Even surface elements like rugs contribute by absorbing ambient noise and enhancing the overall acoustic comfort of the space.
Ceilings
Designed as sound barriers, suspended ceilings should contain a thermal insulation layer and air space, which helps sound energy to dissipate. Suspended ceiling usually hides pipes and air conditioning equipment, so they take part in lowering their work noise.
Sound Modelling and Testing
The use of software that predicts the noise levels in the building during the design process analyzes and reveals the ways of sound transfer through the structure and assemblies. According to the Sound Transmission Class, the parameter defined in building standards for each partition, we can define ways to improve the sound comfort.
The only disadvantage that might appear in improvements of sound performance of a mass timber building is mass timber elements’ surfaces hidden under or behind various coverings that make the structure more complex, but also life and work in these environments more comfortable.
