Digital Realty: Paris Les Ulis Campus

Digital Realty's Les Ulis campus sits on the eastern edge of the Courtabœuf business park in Les Ulis (Essonne), about 30 km south of Paris. It lies between the A10 motorway and the farmland of Villejust, near the A10/N118 interchange. The 15.7-hectare site was farmland, then woodland after 1970, and a 225 kV overhead line already crossed it.

Interxion, then part of Digital Realty, launched the project. A dedicated subsidiary, Digital Les Ulis, bought the land in July 2022. The building permit and ICPE environmental authorisation followed a public inquiry in March-April 2022. The prefecture granted the authorisation on 5 July 2022. Digital Realty dropped one of three planned buildings to preserve 1.54 hectares of woodland. It also planted 1.81 hectares of new woodland. In January 2024 the campus went into Digital Realty's hyperscale joint venture with Blackstone. Blackstone-managed funds hold 80%. Digital Realty holds 20% and develops and operates the site.

The campus is planned as two two-storey buildings with about 54,000 m² of floor area: PAR13 (built) and PAR14 (planned). RTE feeds the campus at 225 kV through two underground links that tap the Chevilly–Villejust and Robinson–Villejust 225 kV lines. Each building has its own substation. Diesel generators sit on outdoor platforms, with fuel tanks under each set for 72 hours of autonomy. The full environmental file covers 64 generators. 100% French renewable guarantees of origin back the electricity supply. Bouygues Bâtiment Industrie, Bouygues Energies & Services (now Equans) and Reid Brewin Architects built PAR13. Terrell was the structural engineer.