Sanchez’s silk mill acoustics in Shinkenchiku magazine

In circulation since 1925, Shinkenchiku magazine is considered to be one of the most prestigious architectural publications, featuring contemporary architecture and architectural topics such as environmental issues, urbanism and renovation projects. The magazine has been endorsed by numerous renowned architects for its detailed presentation of contemporary Japanese architecture with high quality plans and drawings. As a result of his participation in the acoustic design of the multipurpose hall and galleries at Tomioka Silk Mill, Antonio Sanchez, Senior Acoustic Consultant from RSK Acoustics was featured in the March issue of this distinguished magazine.

Established in 1872, the Tomioka Silk Mill (富岡製糸場, Tomioka Seishijō) was Japan’s first modern silk factory for processing silkworm cocoons into raw silk. The Japanese government, with the help of French specialists, built the mill as a model factory to improve the quality of silk produced in Japan. In 2014, Tomioka Silk Mill became a UNESCO World Heritage Site.

As part of the repair work undertaken for the mill’s preservation, completed in October 2020, a nested earthquake-resistant structure with steel frames and tempered glass was introduced within the design. We undertook the repair work in this way to maximise the experience of the “Nishi Cocoon”, where the multipurpose hall and galleries were planned to be, by preserving the atmosphere of its original design.

The acoustic design of the multipurpose hall was very challenging, as hard materials such as the glass that was installed in parallel walls and ceilings reflect sound, creating an increased reverberation time and the appearance of an unpleasant flutter echo. In general, we would use sound-absorbing materials to control the reflections; however, their installation in the glass surfaces of this hall would have obscured the view from the original building. As a solution, the placement of acoustic diffusers in the partition wall between the multipurpose hall and the galleries was proposed. We carefully studied the optimal design, shape and material of these diffusers using computational software models based on geometrical acoustics. As a result, we significantly reduced the acoustic disturbances of the hall and ensured speech clarity, thus providing good acoustic conditions for future events, from speech performances to acoustic and amplified music.

Our project received the International Council on Monuments and Sites (ICOMOS) Japan Award in 2020 for projects involved in the protection and preservation of Japanese cultural heritage.

The issue, in Japanese only, is available at the Architecture and Urbanism magazine website.