FIDIC Contracts: The Rainbow Suite and Singapore Forms

On international construction projects, one family of standard forms appears more often than any other. FIDIC contracts, published by the International Federation of Consulting Engineers (Fédération Internationale des Ingénieurs-Conseils), are used across Asia, Africa, the Middle East and Europe, and are frequently adopted by development banks for the projects they fund. Each book is identified by the colour of its cover, which is why the collection is known as the Rainbow Suite.

This article explains the main FIDIC books and what distinguishes them, the key changes in the 2017 editions, the mechanisms that matter most in practice, and how FIDIC compares with the standard forms more commonly used for building work in Singapore: PSSCOC in the public sector and the SIA and REDAS forms in the private sector.

The Rainbow Suite at a glance

The core of the suite consists of three main construction contracts, each suited to a different allocation of design responsibility and risk.

Red Book: Conditions of Contract for Construction

For works designed by the employer (or the employer’s consultants), with the contractor building to that design. Payment is usually by measurement of completed work against a bill of quantities. An independent Engineer administers the contract. This corresponds broadly to traditional procurement.

Yellow Book: Conditions of Contract for Plant and Design-Build

For works where the contractor carries out most of the design to meet the employer’s requirements, typically for electrical and mechanical plant and for design-build projects. Payment is usually a lump sum. The Engineer continues to administer the contract.

Silver Book: Conditions of Contract for EPC/Turnkey Projects

For projects where the contractor takes responsibility for design, procurement and construction and accepts a greater share of risk, including much of the risk relating to the employer’s requirements and ground conditions. There is no Engineer; the employer administers the contract directly. It is aimed at projects where certainty of price and completion is paramount, as described in our article on the EPC contractor.

Other books

Green Book — a short form for simpler, lower-risk works; the second edition was published in 2021.
White Book — the client–consultant model services agreement for appointing designers and other consultants.
Gold Book — for design, build and operate projects, combining construction with a long operation period.
Emerald Book — for underground works and tunnelling, published in 2019, with particular attention to ground risk.
Pink Book — a version of the Red Book harmonised for projects financed by multilateral development banks.

The 2017 editions and 2022 reprints

The first editions of the Red, Yellow and Silver Books were published in 1999 and remained in wide use for nearly two decades. FIDIC published second editions of all three in December 2017. They are considerably longer than their predecessors and make several significant changes:

More detailed procedures — clearer, more prescriptive steps for notices, programmes, variations and claims.
Reciprocal claims procedure — employer and contractor claims are dealt with through the same mechanism, with time limits for both parties.
Separation of claims and disputes — claims are handled under one clause, and the resolution of disputes, including the Dispute Avoidance/Adjudication Board (DAAB), under another.
Emphasis on dispute avoidance — the DAAB is intended to be a standing board that helps the parties avoid disputes, not only decide them.
Engineer’s role — clearer expectations of neutrality when the Engineer determines claims.

In November 2022 FIDIC issued reprints of the 2017 Red, Yellow and Silver Books incorporating amendments, consolidating earlier errata and clarifying several provisions. The reprints are generally regarded as the definitive version of the second editions, but they do not change existing contracts automatically; parties have to adopt the amended text expressly. Many projects also continue to use the 1999 editions, and it is essential to know which version a contract is based on.

Key mechanisms in practice

Whichever book is used, a few mechanisms do most of the work in managing a FIDIC contract.

Notices and time bars

FIDIC contracts require prompt notice of claims. A contractor who becomes aware of an event giving rise to a claim must give notice within a specified period, and failure to do so may bar the claim. Strict compliance with notice provisions is one of the most important disciplines for both parties.

Variations

The Engineer (or employer, under the Silver Book) may instruct variations, which are valued under the contract’s procedure. The contractor may also propose value engineering changes.

Particular Conditions

FIDIC forms are designed to be used with General Conditions that remain unchanged and Particular Conditions that adapt the contract to the project and governing law. FIDIC’s guidance sets out golden principles warning against amendments that upset the balance of risk. Heavy amendment is common in practice, so reading the Particular Conditions is as important as knowing the standard text.

How FIDIC compares with forms used in Singapore

For domestic building work in Singapore, local standard forms are much more common than FIDIC. FIDIC is more likely to be encountered on projects with international owners, contractors or funding, and by Singapore consultants and contractors working overseas.

PSSCOC for public sector projects

The Public Sector Standard Conditions of Contract, maintained by BCA, are the standard forms for public sector construction in Singapore. The current editions include PSSCOC for Construction Works 2020 and PSSCOC for Design and Build 2020, with simplified “PSSCOC-lite” versions issued in 2025 and collaborative contracting option modules under pilot. Like the Red and Yellow Books, PSSCOC distinguishes between employer-designed and contractor-designed work, but its procedures, roles and terminology are drafted for Singapore’s public procurement and legal environment.

SIA forms for private building work

The Singapore Institute of Architects publishes standard building contracts widely used for private building projects, administered by the architect. They are tailored to building work and to local practice, and our article on the SIA contract explains their structure.

REDAS for private design and build

The Real Estate Developers’ Association of Singapore publishes design and build conditions widely used by private developers. These tend to be more developer-friendly in allocating risk than the SIA forms.

Across all of these, Singapore’s statutory framework applies regardless of the contract form, including the Building and Construction Industry Security of Payment Act for progress payments and adjudication. Choosing between forms is part of the wider procurement decision discussed in our overview of types of construction contracts.

Choosing and using FIDIC contracts well

The right FIDIC book follows from who designs the works and how much risk the employer wants the contractor to carry. Choosing the Silver Book for a project where the employer cannot provide reliable information is a common mistake: contractors price the risk heavily or decline to bid. Equally, using the Red Book where the contractor is designing creates confusion over responsibility.

Once the contract is signed, discipline matters more than drafting. Keeping records, issuing notices on time, maintaining an updated programme and using the DAAB early all reduce the risk of disputes. For a structural engineer, the contract defines the design responsibility, review procedures and approval timelines that shape how engineering information flows through the project, which is why understanding the form is part of practising responsibly on international work.

Frequently asked questions

What is the difference between the FIDIC Red, Yellow and Silver Books?

The Red Book is for employer-designed works paid by measurement; the Yellow Book is for contractor-designed plant and design-build works, usually lump sum; and the Silver Book is for EPC/turnkey projects where the contractor takes most of the risk and there is no Engineer.

Which edition of FIDIC contracts is current?

The second editions of the Red, Yellow and Silver Books were published in 2017, with reprints incorporating amendments issued in 2022. The 1999 first editions are still used on many projects, so the version must always be confirmed.

Are FIDIC contracts used in Singapore?

They are used on some projects, particularly with international parties or funding, but domestic building work more commonly uses PSSCOC for public projects and SIA or REDAS forms for private projects.

What is a DAAB?

A Dispute Avoidance/Adjudication Board is a panel appointed under the 2017 FIDIC contracts to help the parties avoid disputes and, where they arise, to give decisions that are binding unless and until revised by amicable settlement or arbitration.

Working on an international or design-and-build project and need clear structural design responsibility? Talk to our consultancy or get in touch.