01 — The NF X35-102 benchmark
NF X35-102 deals with the ergonomic design of office workspaces. Its best-known benchmark is simple: at least 10 m² per person in an office and at least 15 m² per person in a noisy shared space. It also addresses desk layout, circulation and environment (noise, light). It is not a legal requirement in itself, but ergonomists, occupational health services and many specifications refer to it; departing from it should be justified.
The 10 m² figure is working space per person, not leased area per employee. The two are often confused in property listings.
02 — From space per desk to floor plate
To estimate a floor plate, add three blocks: workstations, shared spaces (meeting rooms, focus rooms, phone booths, break areas) and support and circulation areas. The weighting depends on how you work.
| Block | Assumption | Indicative area |
|---|---|---|
| Workstations | 60 people × 10 m² | 600 m² |
| Meeting rooms | 4 rooms for 6 to 8 people, 15 to 20 m² each | 60 to 80 m² |
| Focus rooms and phone booths | 1 per 8 to 12 people | 20 to 40 m² |
| Break and café area | A central meeting place | 40 to 70 m² |
| Reception, storage, print | Depending on activity | 30 to 60 m² |
03 — Hot-desking: count people present, not employees
With shared desks, the right figure is peak simultaneous occupancy, measured over four to six representative weeks (sensors, badges, bookings). Peak days, often mid-week, set the size; sizing on the average leaves people without desks. Space saved must return to teams as useful areas: personal lockers, project rooms, quiet rooms.
04 — Dimensions that matter as much as area
Two floors of the same area are not equal: columns, depth from the façade, window grid and riser positions decide what can really be laid out.
- clearance behind a task chair: about 1 m to stand up without blocking circulation;
- main circulation: wide enough to pass and for evacuation, to be checked against the building’s regulations;
- desks perpendicular to windows limit glare on screens;
- meeting rooms: about 70 cm of table edge per person, plus clearance around the table.
05 — Our method: the test fit
Before signing a lease or starting works, we draw two or three layout scenarios on the actual plan: number of desks, rooms, booths and the area of each block. The test fit quickly shows whether a floor suits the headcount and what each option gains or loses.