Office buildings: fire safety, accessibility and environmental regulation

An office building is defined by its exclusive or dominant use for administrative or commercial work, without public access, or with reception limited enough not to justify classification as a building open to the public. It falls under the labour code's fire safety provisions, the workplace order of 4 November 1993, and the labour code's accessibility rules. Above 50 m it moves into the high-rise regime.

ℹ Private office building or type W? Type W: the public has access — clients, users, unaccompanied visitors — so the public-building regulation and the safety commission apply. A private office building: access only for staff or accompanied visitors, so the labour code applies. A mixed building — a headquarters with a public reception area — has its public part under the public-building regulation, with compartmentation from the rest. Where there is doubt, the client should consult the municipality or the safety commission to clarify the classification.

Commercial workplaces are subject to the labour code's fire provisions, which set requirements on fire resistance, escape routes, means of rescue and evacuation plans. Floors between levels are REI 60, or REI 120 in basements. Partitions separating high-risk rooms — large archives, data centres, cooking — are REI 60 with an EI 60 door.

The labour code requires two exits per level above 20 people. The minimum width of escape routes is two units of passage, 1.20 m, for 50 to 100 people, and three units for 100 to 200. An evacuation plan displayed in each office and an annual evacuation drill are mandatory. Automatic fire detection is recommended by insurers for floorplates above 300 m².

New office buildings are subject to the acoustic regulation for commercial buildings, the order of 25 April 2003. Minimum insulation between rooms is set by use: cellular offices against open plan, meeting rooms, staff catering.

Reverberation in open-plan space is governed by the international standard on open-plan office acoustics, through steady-state sound pressure and distraction distance. Good acoustic treatment of open plan has become a certification criterion and a strong commercial argument for landlords.

Accessibility obligations for a private office building flow from the labour code. They are less demanding than for buildings open to the public but require accessible workstations, sanitary accommodation, canteen and meeting rooms for disabled workers.

ℹ Accessibility under the labour code → At least one accessible workstation per activity carried on in the building. → Accessible sanitary accommodation: at least one accessible WC per level occupied by workers. → A lift is mandatory on multiple levels above 50 workstations on upper floors. → Accessible parking: at least 2 % of spaces, minimum one, reserved for disabled staff. → Where part of the building is open to the public, the labour code and the public-building regulation both apply to the parts concerned.

The environmental regulations apply to new offices whose planning application was filed after 1 July 2022. Thresholds are defined for office use. Unlike housing, the commercial regime does not oblige abandonment of gas, but the energy and carbon thresholds make retaining a gas boiler difficult without substantial renewable input.

ℹ Points of vigilance Glazing ratio: above 50 % of the façade the bioclimatic indicator degrades sharply, making external brise-soleil or selective glazing necessary. High internal gains — dense open plan, a data centre — create substantial cooling demand: free cooling and adiabatic cooling should be assessed. Construction carbon: a standard concrete structure is penalised, so low-carbon concrete or a mixed concrete and timber frame becomes necessary for the 2025 thresholds. The commercial energy decree: where the building is let to third-party occupiers above 1,000 m², tenants must reduce their consumption by 40 % by 2030, 50 % by 2040 and 60 % by 2050 — to be reflected in the leases.

ℹ ✔ Summary for the economist Construction cost of a standard office, excluding land, external works and tenant fit-out: 1,530 – 2,550 €/m² of floor area. A premium office with double-skin curtain walling, high certification and smart building systems: 2,550 – 4,080 €/m². Basement parking: 20,000 – 40,000 € per space, covering excavation, structure, lighting and smoke control. On the commercial energy decree, inform the landlord client of the performance obligations falling on future tenants. Certification adds 3 to 8 % on construction plus certification fees of 30,000 to 100,000 €.

The public-building article covers type W offices open to the public. Fire safety and fire resistance are developed in the fire article. The environmental regulations, across all building types, have their own article. For office towers above 50 m, see the high-rise article. The mixed-use article covers buildings combining offices and housing.

ℹ The construction economist on demand. Your office building deserves pricing that takes in the labour code, the environmental regulations and the commercial energy decree. Submit your programme on quostra.com and an economist prices the regulatory items from the brief.

Reference basis of the figures

The ratios per square metre and per item on this page are stated in January 2026 values. They were updated from January 2025 values, the basis adopted for the whole cocoon, using the BT01 all-trades index published monthly by INSEE on its 2010 base: 132.0 in January 2025, 134.7 in January 2026, a coefficient of 1.0205.

The global amounts quoted as examples, and any rents, charges or receipts expressed per year or per night, remain on their own basis: a building cost index does not apply to them.

To bring the ratios forward, apply the usual revision formula: updated value = page value × (BT01 for the month in question / 134.7). The BT01 measures contractors' input costs, labour at 44.9 % and materials at 36.5 %, not the prices actually tendered.

• Construction regulations in France
• High-rise buildings
• New offices open to the public