Voir en


A quiet revolution is under way at Prévessin

With many developments planned or under consideration, this is the decade of CERN’s Prévessin site


Storage areas of the LHC magnets on the Prévessin site seen from the air
Prévessin site seen from the air (Image: CERN)

From infrastructure projects to environmental and public engagement initiatives, the Prévessin site is a hive of activity that is set to escalate over the coming years. Some, like the construction of a new Robotics building, began in 2020. Others won’t be realised until around 2030. Sustainable modernisation takes time and money, but CERN consistently aims for a greener future for its state-of-the-art facilities. The developments at Prévessin rely on a collaboration and a continuous dialogue between sectors. The inclusion of various opinions is the key to our success. 

No fewer than 15 projects are planned or under consideration for the site. The new Robotics building is nearing completion. Its laboratories, offices and technical rooms will be open for business by October this year. The new building will bring the activities of the Controls Electronics and Mechatronics group from the Beams department (BE-CEM) together in a single location.

CERN’s new Computer Centre, a modern and energy-efficient structure that will meet the new computing needs of the community, will also be located on the Prévessin site. It is scheduled to be operational in the second half of 2023.

The new Building 777, at 9000 square metres, will provide new offices and labs for the Accelerators and Technology sector (ATS). Open spaces and conference rooms have been designed for more dynamic interaction, while the landscaping will favour outdoor working spaces and an events area. Finally, around 300 new parking spaces are planned, which will include soft mobility infrastructure, as well as a new restaurant – to everyone’s delight. Building 777 is scheduled for delivery in the second quarter of 2026. 

Buildings 904 (mostly used by the Experimental Physics (EP) department), 926 and 927 (Technology (TE) department) are also entering a consolidation phase. Waterproofing, metalworks, collective protective equipment, smoke extraction systems and downpipes – all these structures will undergo major renovation between March and November 2022.

Prévessin’s over 7 km of beamlines and associated technical systems, in operation since the 1970s, are also earmarked for attention through the North Area (NA) consolidation project. The NA is home to a vibrant programme of physics experiments, R&D and test beam activities, with more expected in the framework of the Physics Beyond Colliders study. While some of the site’s beam facilities have already benefited from safety upgrades, the first phase of NA consolidation is scheduled to run until the end of Long Shutdown 3.

The fences enclosing the whole site will be consolidated, with landscaping improvements made where appropriate.

But the Prévessin development plans are not just about infrastructure. Mobility is an important aspect that has not been overlooked in the general planning. The importance of environmentally friendly upgrades is integral to this. The creation in 2020 of new cycle lanes encouraging soft mobility will soon be reinforced with over 50 additional bicycle parking spaces in the parking lots of Buildings 864-866 and 947. Charging stations for electric bikes and quick-plug (11-22kW) charging stations for electric vehicles are being studied, with a first pilot scheduled for the end of 2021. 

Between 2023 and 2025, the car parks at Buildings 864-865 (ATS) and Route Touschek will be completely overhauled, with rainwater network renovation, reprofiling of the base structure and a complete redesign to meet current standards and needs.

For those who favour public transport, a new bus stop for TPG line 66 is planned at the entrance of the Prévessin site.

CERN is also working on the implementation of three other projects. A new entrance to reflect more strongly the importance of the Prévessin site and improve its capacity to welcome visitors, a heat recovery plant from the computer centre to heat all the buildings of the Prévessin site from day one, limiting the operation of gas boilers to the few peak cold days of the year, and a new retention basin to protect local watercourses. All in all, there’s a great deal coming up at Prévessin, and we’ll be reporting on each of these initiatives over the coming months and years.