Three models to run your office works, three approaches to responsibility and budget. Discover the strengths, the limits and the use cases of each approach to choose the one best suited to your fit-out project.
Definitions
Each method fits a specific use case. The right choice depends on the scope, the schedule constraints, the level of price commitment expected and the maturity of the client team.
An integrated method where a single contractor takes on design, construction, fit-out and furnished handover under one contract. This is the Kytom method.
Best suited to 500–3 000 sq m projects with a tight schedule and a single signature expected.
A method where the architect and engineering firms handle design, contractor selection and site supervision across separate packages. The client signs N contracts.
Best suited to atypical or heritage projects where the architectural choice outweighs the schedule.
A method where a single firm carries out the works based on studies provided by the client project management team. Design and construction remain separate.
Best suited to projects over 3 000 sq m where the client has an in-house technical team.
Comparison
The table below summarises the gaps observed on French office projects of 1 000 sq m. Kytom thresholds align with the Cerema framework and the ADEME method for carbon footprint.
| Criterion | Design & Build | CMO (separate packages) | General contractor |
|---|---|---|---|
| Number of client contracts | 1 | 5 to 9 | 2 (PM + GC) |
| Reference lead time for 1 000 sq m | ~12 weeks | 20 to 26 weeks | 16 to 22 weeks |
| Price commitment | Lump sum at signature | Estimate then adjustments | Lump sum on works only |
| Schedule commitment | Single handover penalty | Per-package penalties, diluted | Works penalty, design excluded |
| Coordination of stakeholders | Integrated project lead | OPC or in-house management | GC on site, PM on design |
| Furniture and fit-out | Included, furnished handover | Separate contract | Separate contract |
| Architectural freedom | Framed by the 12-week method | Maximum | Framed by PM studies |
| Tertiary decree | Cerema applied from programming | Dedicated engineering office | PM studies |
| Carbon footprint | ADEME method built in | Optional, separate provider | Optional, separate provider |
| Typical scope | 500–3 000 sq m | Any | > 3 000 sq m |
Sources: Kytom observations 2006–2026 across 1 200 delivered projects; public frameworks Cerema (energy performance) and ADEME (carbon footprint).
When to choose what
The right trade-off depends on the schedule-scope pairing and the level of single-contract signature expected by the real estate department.
When handover is expected within the quarter following signature, when the real estate department wants a single point of contact and when the scope is set at 500–3 000 sq m.
When the project rests on a strong architectural stance or a heritage building, when trade-offs must be debated at length and when the client team manages coordination.
When the scope exceeds 3 000 sq m, when the real estate department has an in-house design unit and when the contract is awarded after an architecture competition.