On Friday, 14 April 2026, CERN celebrated an important milestone in the construction of the future Building 777 on the Prévessin site: instead of laying the traditional foundation stone, the project started with the installation of its very first timber beam (or “la première poutre”), a reflection of the building’s sustainable design.

Mar Capeáns, CERN’s Director for Site Operations, architect Søren Øllgaard and Bernard Chauvet, Mayor of Prévessin-Moëns, were present to install the first timber beam, alongside CERN representatives, local authorities and project partners, marking the start of construction.

As Bernard Chauvet noted during the ceremony: “This project reflects the belief that fundamental research and sustainability are closely linked and must serve a more sustainable world.” In this spirit, Building 777 signals a shift in how CERN builds. As the Organization’s first timber construction, it puts sustainability at the forefront. As outlined in the Organization’s 2023–2024 Environment Report, CERN’s infrastructure projects are designed to minimise environmental impact at every stage. Internationally recognised certification schemes, such as BREEAM (Building Research Establishment Environmental Assessment Method), are used to evaluate performance across a wide range of criteria, including energy use, material selection and overall integration into the surrounding environment.

Building 777 is one of the projects developed under this methodology. Initiated in 2023 and scheduled for completion in 2027, it is set to become a central hub for the Prévessin site, hosting offices, a restaurant, laboratories and workshops. Once completed, it will stand as an example of CERN’s commitment to combining cutting-edge science with sustainable design.

For more information about the Building 777 project:
https://building777.web.cern.ch/

Follow construction updates:
https://building777.web.cern.ch/news/