FIDIC Yellow Book (Plant & Design-Build)

The FIDIC Yellow Book is the informal name for the FIDIC Conditions of Contract for Plant and Design-Build, covering contracts where the contractor is responsible for both the engineering design and the physical construction, and where payment is made on a lump-sum basis tied to the employer's defined output requirements rather than a remeasured bill of quantities.

What is the FIDIC Yellow Book (Plant and Design-Build)?

The Yellow Book was originally developed for mechanical and electrical plant installations -- process equipment, power stations, water treatment facilities -- but is now widely used for any contract where the contractor designs as well as builds. The employer provides an Employer's Requirements document that specifies the performance outcomes, functional standards, and interface conditions the finished works must meet, without dictating how the design is to be achieved. The contractor responds with a Contractor's Proposal at bid stage, and the agreed design forms part of the contract. This reverses the design responsibility found in the fidic-red-book-works, where the employer provides the design.

Payment under the Yellow Book is typically lump-sum against milestones, with quantities and method risks absorbed by the contractor. The engineer retains an administrative role in certifying milestones and determining the value of any variation-order-change-order, though the scope for variations is narrower than under the Red Book because the design itself is the contractor's responsibility. Contractors should also understand the interface between the Yellow Book and consulting agreements; independent checking engineers are often appointed under a fidic-white-book-consulting appointment to verify the contractor's design before construction.

Why the FIDIC Yellow Book matters for bidders

Yellow Book contracts transfer design risk to the contractor, which means the cost of design errors, unforeseen buildability problems, and performance shortfalls sits with the bidder rather than the employer. Suppliers bidding Yellow Book contracts must have genuine design capability or robust subcontracting arrangements with design firms, and must account for design liability, professional indemnity insurance, and interface management costs in their bid price. The lump-sum structure also means that scope ambiguity in the Employer's Requirements becomes a contractor risk: underdeveloped requirements documents are a source of commercial exposure that thorough tender review and pre-bid clarification requests can partially mitigate.

FAQ

How is the Yellow Book different from the Red Book?

Under the Red Book, the employer provides the design and the contractor builds to it. Under the Yellow Book, the employer defines performance requirements and the contractor designs and builds to meet them. This shifts design risk -- and design liability -- from employer to contractor.

Is the Yellow Book used for civil works or only for plant?

The Yellow Book originated in plant and mechanical/electrical work but is now widely applied to civil infrastructure, building, and mixed projects where design-and-build procurement is preferred. Development banks use it for power, water, and process infrastructure projects.

What is the Employer's Requirements document?

The Employer's Requirements is the key technical document in a Yellow Book contract, setting out the functional, performance, and quality standards that the contractor's design must achieve. Ambiguities or gaps in the Employer's Requirements create contractor risk, so thorough review during the bid phase is essential.