Architects PCA-STREAM and interior designer Patrick Bouchain have completed La Source Vive, a 500-seat chamber music hall in Évian-les-Bains, France, featuring an organic, gourd-like oval plan and a plaster-surfaced concrete shell engineered to achieve a reverberation time of 1.8 seconds.
The Architecture of Sound in Évian-les-Bains
- Design and Location: Conceived by PCA-STREAM with interiors by Patrick Bouchain, the 500-seat hall is nestled into the wooded hills above Lake Geneva for the use of the resort’s music festivals.
- Acoustic Engineering: Utilizing a digital twin developed with the META acoustic laboratory, the structure features a nested-shell design, pink beech wood blocks, and sculpted plaster relief to manage distortion and echoes typical of curved rooms.
- Material Innovation: Built with a cast-concrete inner dome poured over timber formwork, the hall is covered by a second timber envelope clad in a copper skin with an insulating cavity in between.
Constructing the Concrete and Copper Shell
Curved architectural surfaces can act like magnifying glasses for sound waves, creating distortion and unpleasant reverberation. To combat this physical hurdle for the new venue in Évian-les-Bains, France, the design team at PCA-STREAM worked from the inside out. Once the interior dome’s geometry was locked down, engineers and architects settled on a cast-concrete shell poured over timber formwork. Instead of exposing the raw concrete, they finished the surface in plaster to evoke the acoustic and visual quality of old churches.
copper shingles wrap curving concert hall 'la source vive' in évian, france https://t.co/SEIVWHFSmK pic.twitter.com/i4Nyu7BxXA
Encasing that primary acoustic shell is a second envelope. A technical cavity separates the insulated concrete core from an outer timber structure clad in insulation, battens, and a copper roof. This layered sandwich handles both thermal insulation and sound management while keeping energy consumption low. Inside this copper skin, tiered seating unfurls petal-like from the center, flanked by a forest of wooden blocks designed to break up strong reflections and scatter stray sound waves.
Simulating Acoustics with the META Laboratory
While the late acoustician Albert Xu established the primary design decisions before his passing, PCA-STREAM partnered with the META acoustic laboratory to build a digital twin of the hall. Philippe Chiambaretta noted that this digital model allowed the design team to run precise simulations early in the process. They tested everything from seat design and tiered material choices to the precise shape of sound baffles.
The reliance on simulations didn’t stop once construction began. At each stage of the build, the architects took physical measurements on-site and cross-referenced them against the model’s predictions to eliminate discrepancies. That rigorous digital-physical loop helped yield a room with a reverberation time of 1.8 seconds when full.
| Hall Feature | Design Specification | Acoustic Function |
|---|---|---|
| Capacity | 500 seats | Chamber music scale |
| Reverberation Time | 1.8 seconds (full capacity) | Baseline for the hall |
| Interior Surfaces | Sculpted pink beech blocks and varied plaster relief | Diffuses strong reflections and prevents echoes |
| Exterior Envelope | Copper-clad timber over concrete shell | Provides thermal insulation and structural isolation |
Connecting to the Alpine Festival Landscape
La Source Vive joins its sister venue, La Grange au Lac (1993), a shoebox-style timber hall designed by Patrick Bouchain and the late acoustician Albert Xu. Sited collectively for the resort’s music festivals, the new hall reflects the vernacular landscape of Alpine Switzerland through form and materials. Overhead, a suspended ceiling reflector directs acoustic information down toward both the audience and the musicians.
Despite an exterior profile that resembles a dewdrop, La Source Vive relies on structural conditions to achieve its performance metrics. The result is an enclosed instrument where tactile materials, natural light, and modern acoustical engineering converge.
