The Paris office market in 2026
At the end of September 2026, the office vacancy rate stood at 6.9% in the Paris Central Business District (QCA), compared with 5.1% a year earlier, and at 11.2% across Île-de-France as a whole. Prime rent in the Central Business District stood at €1,250 per m² per year, up 4% year on year (Cushman & Wakefield, Immostat, 6 October 2026). Over the rolling twelve months to the second quarter of 2026, the average rent there was €1,099 per m² for new space and €774 for second-hand space (BNP Paribas Real Estate, rolling twelve-month averages).
These figures say something simple: in Paris, every poorly used square metre is expensive. The decision on floor area calls for a space-use assessment rather than a ratio.
The rules that shape a Paris project
- Receiving the public: a practice, branch or head office that receives clients may fall within type W ERPs (buildings open to the public: offices, administrations, banks), with a works authorisation required even where no permit is needed. See Offices open to the public and, for Paris applications, dossier-erp-paris.fr.
- Designated use of premises: changing from office use to another designated use with alterations to the façade or the structure requires a building permit (Planning Code, art. R421-14 c). Act no. 2025-541 of 16 June 2025 opened up new possibilities for converting offices into housing.
- Older buildings and co-owned buildings (copropriétés): hours for works, goods lifts, common parts, façades: the building's constraints have to be read before any costing.
- Energy: from 1,000 m² of tertiary-sector floor space, the Tertiary Decree (Éco Énergie Tertiaire scheme) applies to both the owner and the tenant.
What we do in Paris
Workplace strategy and space-use assessment, test fits before signing a lease, briefing, design, site supervision (maîtrise d'œuvre), works in occupied premises. Meetings take place on site, at your premises, or at rue du Cherche-Midi.