Facing the city and the A1 motorway heading north, the City One project deploys approximately 80 metres of facade in the extension of the SFR Campus, near the Stade de France. It is designed like a «bastide» constructed in contrast over a vast wooded space, providing calm and serenity. The northeast corner, made entirely of glass, is a strong signal that marks the entrance to the business centre.

City One was designed with the aim of providing its users with privileged conditions of comfort and use. The workspaces have been designed to offer constant performance, whether they are organized in partitioned, shared or open offices. On the upper floors, the various accessible terraces offer convivial spaces for users.

The building also includes a section open to the public comprising a staff restaurant, an auditorium, retail outlets and a crèche, together with 2,500 sqm of green spaces, three underground levels for deliveries, archives, parking and mechanical rooms.