Accoya® is a modified wood created through a patented acetylation process that alters the cell structure of sustainably sourced timber to improve its durability, dimensional stability, and moisture resistance. Accoya® Cladding was selected as the façade material for the Stadtcasino Basel Extension.
In 2012, Herzog & De Meuron began the restoration and extension of the Stadtcasino Basel Stehlin concert hall. The project addressed the western section of the building, where a smaller extension had been added in the 1930s. The intervention sought to reinforce the concert hall as a stand-alone building while expanding its facilities with a new entrance, foyer, backstage areas and supporting facilities.
Completed in 2020, the extension incorporates approximately 1,100m2 of Accoya® wood cladding, developed to reference the neo-Baroque stone architecture of the original building. Working with engineers Pirmin Jung AG, the timber façade was designed using profiled and joined Accoya® elements that reproduce the proportions and the detailing of the existing masonry. The wood supplier applied three layers of grey coating supplied by Keim Farben to achieve a finish that matched the color and appearance of the stone façade.
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The dimensional stability of Accoya® timber cladding and its compatibility with coatings allowed the material to be profiled, joined, and finished to reference the appearance of the original stone façade. From a distance, the cladding maintains the visual character of the existing architecture, while at closer range, its wood grain and detailed fabrication become visible. This approach establishes a relationship with the original building while distinguishing the new intervention through the use of timber.
A test wall incorporating 17 different Accoya® timber profiles was constructed to evaluate the performance of the wood and coating over two years. The testing confirmed the suitability of the selected profiles and finishes prior to completion of the project. The resulting façade integrates the existing and new sections of the building while retaining subtle differences in material and construction.
Project Data
