OSA / Europe | 2021

Kevin Guidoux, has been involved in AB.Lab (ArtBuild’s research and innovation studio) since his arrival at ArtBuild in 2017. After the delivery of the Agora in 2021, he took on the role of structuring AB.Lab as its director, driven by the ambition to broaden perspectives on architectural practices while exploring more ethical and sustainable solutions. This initiative allowed him e to engage with front runners, share our convictions and values, and work on projects across France, Belgium, Spain, Switzerland, the Netherlands, and Japan.

In this context, I would like to showcase our ongoing research on the bending of CLT (Cross Laminated Timber) panels. This work began with small-scale models and has culminated in the reuse of the monumental Ephemeral Auditorium at the Grand Palais in Paris.

Their primary objective were to question the increasing use of CLT panels in the construction industry, while ultimately pushing their technical boundaries to propose aesthetic and functional alternatives for recycling. The OSA process (from the Latin osaven, meaning “bird bone”) has extended the undeniable constructive and aesthetic potential of CLT panels.

The CLT panels undergo subtractive machining through the lattice hinge technique, which provides flexibility by carving a series of discontinuous, longitudinal, parallel, and staggered lines into the panels.

The first full-scale prototype, the Nautile Sylvestre, was built for the Libramont Fair (Belgium) in 2019. This project demonstrated, for the first time, the structural potential of cold-bent CLT panels. The structure supported up to 20 visitors at once, allowing them to ascend to a panoramic viewpoint overlooking the fairgrounds and surrounding forest.

Biomimetically inspired by the banana plant’s extraordinary structural efficiency, the prefabricated structure consists of 16 panels forming two interlocking spirals connected by stair treads. A deeply introspective demonstration of material sensuality, the design appeals to tactile and olfactory senses, enhanced by the interplay of light through the curved strata of structural timber.Building on the momentum created by the Nautile Sylvestre, the Ephemeral Auditorium, a breathtaking wooden centerpiece for the 10th edition of the Forum Bois Construction, was installed at the Grand Palais Ephémère in Paris for a few days. This project represents a significant evolution in creativity and reflection: unlike the Nautile Sylvestre, the Ephemeral Auditorium adapts to various challenges through the versatility of its forms.

All 64 Douglas fir panels, each measuring 2.3 x 5.25 x 0.06m, come together to form an undulating wooden “curtain.” This self-standing structure creates a free-plan layout spanning 475 m². It is designed to be rapidly assembled and disassembled, offering the acoustic and visual intimacy required for plenary lectures and events. The truss-like diagonal connections between the curved panels draw inspiration from bird bone anatomy, showcasing remarkable lightness and structural efficiency.In 2024,he entrusted with designing the entire scenography for the upcoming “Universal Exhibition of Wood and Bio-Based Materials” during the 2025 Forum Bois Construction. This event, held within the 13,000 m² of the Grand Palais in Paris, will also feature a reimagined version of the Ephemeral Auditorium.

The exhibition highlights the versatility of wood and bio-based materials, emphasizing their constructive, furniture, demonstrative, educational, and poetic qualities.

Category:Display/ InstallationsLocation:Belgium and FranceArchitect: Kevin Guidoux, FranceArchitecture Office:ArtBuildLead Architects:Steven WareDesign Team: Kevin Guidoux as project's directorProject Management:Kevin Guidoux Photographer: Tristan Deschamps, Jean-Pierre Ruelle