CERN signs contract for Building 777 construction
2 October 2025
CERN has signed a major contract for the construction of Building 777 (B777) on the Prévessin site, marking a significant milestone in the Organisation’s long-term campus development strategy. The works will be carried out by Demathieu Bard, responsible for the overall construction, and Briand Construction Bois, who will deliver the timber structure and façade. Construction is set to begin in the coming weeks and will continue until the end of 2027.
Designed by Henning Larsen Architects, B777 will provide modern offices with around 530 workspaces, ten new laboratories, a new Restaurant 3, as well as conference and meeting spaces. It will serve as a central hub for the Accelerator and Technology Sector (ATS) and create a vibrant social and service space at the heart of the Prévessin site.
The project reflects CERN’s ambition to combine functionality with sustainability. With its open timber structure, high environmental standards, and integration into the surrounding landscape, B777 will be a flagship for low-carbon design and workplace well-being. At the same time, it will enable the renovation or removal of outdated buildings, improving efficiency and making space for future developments.
B777 is a cornerstone of the CERN Master Plan 2040, strengthening CERN’s infrastructure to support its scientific mission and its international community for decades to come.
