design and build or architect plus trade packages: method, costs, timelines and selection criteria for project managers and real estate teams on office projects.
"We've been offered both, which one do we pick"
The separate trade packages approach generates 8 to 15% of unbudgeted interface costs (variation orders, rework, technical arbitrations). On an 850 sqm project at 1,200 euros excl. VAT/sqm, that represents 80,000 to 150,000 euros of unforeseen expenses. CBRE studies put the average additional cost related to coordination delays at 6%.
A poorly coordinated project extends transitional occupancy by 3 to 6 weeks. Drawn-out relocation phases are accompanied by an 18% increase in short absences. For a team of 80 employees, the impact on productivity often exceeds the budget savings hoped for on the trade packages.
Under direct project ownership, regulatory compliance (articles R4214 and the tertiary sector decree) rests with the client. An acoustic defect or unresolved public-access building issue exposes the real estate department. It is observed that 30% of commercial handovers include at least one blocking regulatory reservation.
Kytom operates as an integrated general contractor, with interior architect, engineering office and works management under a single contract. Since 2006, more than 1200 clients have been supported with this model, with an average timeline of 12 weeks over an average area of 850 sqm. The approach secures a 90% firm price from the detailed design phase, a single point of responsibility in the event of a reservation and weekly reporting to the project manager. For projects above 2,000 sqm or heritage projects, Kytom readily switches to an architect plus separate trade packages approach managed under project management assistance, in order to preserve architectural quality and competitive tendering of the trades.
Audit of the site, the lease (3/6/9, reinstatement), the project culture and the level of internal maturity. Deliverable: a design and build versus separate trade packages decision matrix, scored on 8 criteria (budget, timeline, image, technical complexity, internal team size, risk, flexibility, employer brand).
Definition of the costed functional programme, area scenarios, budget envelope at plus or minus 10%, master schedule over 16 to 20 weeks. Deliverable: a framing note validated by executive management, the real estate department and the project manager, integrating CAPEX/OPEX arbitrations and financing assumptions.
Architectural, technical and furniture design through to detailed design. Supplier consultations (Vitra, Herman Miller, Knoll for signature projects) and trades. Deliverable: complete tender package, 90% firm price, detailed schedule and safety prevention plan compliant with the regulatory requirements in force.
Execution, pre-handover inspection, clearing of reservations, commissioning and relocation support. Deliverable: handover report with no blocking reservation, as-built documentation, defect liability warranty and an energy assessment aligned with the first target of at least -40% final energy consumption by 2030 and the regulatory milestones applicable to the tertiary building stock.
"We wanted a firm price and a single point of contact. design and build saved us six weeks and avoided three foreseeable variation orders on the technical trades."
For commercial projects of 300 to 2,000 sqm with a tight schedule (less than 16 weeks), an internal team limited to 1 or 2 contacts and a firm price requirement. The model covers 70% of office projects according to Arthur Loyd.
For headquarters above 2,500 sqm, heritage buildings, projects with strong architectural signature or demanding environmental approaches. Competitive tendering of the trades can generate 5 to 8% savings on the technical packages.
No, on an equivalent scope. Market analyses converge: the gap lies between minus 3 and plus 5%. The general contractor absorbs the contingencies which, with separate trade packages, translate into variation orders borne by the project owner.
By requiring a dedicated interior architect within the general contractor's team, signature furniture references (Vitra, Knoll, Herman Miller) and a design validation committee at three milestones: sketch, preliminary design and detailed design.
In design and build, the general contractor is the sole responsible party within the meaning of the Civil Code, which simplifies recourse. With separate trade packages, the architect covers the design and each company its own part, with construction damage insurance policies to coordinate.
With difficulty after detailed design, without losing 4 to 6 weeks. The decision must be settled right from the framing phase, ideally before tendering, on the basis of an objectified decision matrix.