Kytom Observatory

The real cost of office fit-out, month after month

The reference index for real fit-out costs, built on the signed quotes of delivered Kytom projects and cross-referenced with French INSEE indices. Updated quarterly.

Data updated:

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490 €
Median real fit-out cost per sqm, excl. tax
+11.9%
Real fit-out cost increase over 12 months
+8.4 pts
Sector data vs INSEE index

Sources: INSEE BDM · Kytom signed quotes · edition 2026-06

How do we build our index?

  1. 01

    Signed quotes

    Every delivered Kytom project feeds the base: real lots, amounts and floor areas, never declarative data.

  2. 02

    Real weighting

    The cost structure is measured trade by trade on signed quotes, not on a theoretical sector average.

  3. 03

    INSEE cross-referencing

    Official trade-level indices (macroeconomic database) are recomposed along this real weighting.

Since 2006 · 1,200+ B2B projects · France & Spain

What the detailed analysis contains

  • The full index series since 2015, trade by trade
  • The distribution of real costs (quartiles, dispersion) and medians by vintage
  • The detailed cost structure of a fit-out (weights measured on signed quotes)
  • Delivery lead times as ranges by project size (observed ranges + Cerema)
  • The full methodology and the limits of the sample

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Analysis

Edition 2026-06 · updated quarterly

Fitting out a square metre of office today costs roughly 50% more than in 2015. Computed from actually delivered projects, our fit-out cost index reveals an inflation that official construction indices understate, and pinpoints its drivers.

A fit-out cost that has risen by half in ten years

The Kytom office fit-out cost index stands at 150.3 points, against a base of 100 in 2015: interior fit-out costs have risen by roughly 50% over ten years. Over the last twelve months it advanced 11.9%, versus 3.5% for the all-trades INSEE index, the official index understates real inflation by 8.4 points.

This is not about pricing: it is a measurement finding. The generic construction index averages the whole building; interior fit-out follows its own trajectory, and budgeting a project on the official index means starting from a benchmark that understates reality.

Why a dedicated index for interior fit-out?

The reason lies in the cost structure specific to fit-out. An all-trades index averages the entire building, structural work included. A fit-out project concentrates its budget on a few finishing trades, partitioning first, followed by electrical, floor coverings and furniture, precisely those whose prices rose most.

Furniture is the clearest example: producer prices for office furniture (INSEE, CPF 31.01) jumped about 31% since 2015, well beyond average construction inflation. The full trade-by-trade breakdown is in the Observatory’s detailed analysis.

Method

The Kytom index combines INSEE trade-level construction cost indices (macroeconomic database), weighted by the real cost structure of Kytom projects, measured on actually signed quote lines, not on a theoretical sector average. The real cost per sqm divides a project’s total signed cost by its fitted-out floor area. Edition 2026-06: real cost measured on 255 delivered and classified projects.

Single-operator scope, owned: the sample comes exclusively from Kytom projects. Representative of our activity, it may differ from the market as a whole, which is precisely what makes it impossible to replicate without a base of delivered projects, and why we publish the method rather than hide it. Real data, representative of the sector we operate in.