Clause 4.6 [Co-operation] in the FIDIC Yellow Book 1999 vs 2017

Clause 4.6 is embedded within Section 4: The Contractor in both the 1999 and 2017 editions of the FIDIC Yellow Book. It plays a vital role in facilitating coordination and cooperation on site, particularly where the presence of multiple contractors, Employer’s representatives, or public authorities necessitates shared access, responsibilities, and logistics. This clause ensures that the Contractor integrates its activities smoothly within a broader project environment, safeguarding progress and minimizing disruption. It is especially critical in large infrastructure projects where multiple parties perform work simultaneously or in overlapping sequences.

The provision reflects a key collaborative principle in FIDIC contracts: the effective co-existence of various stakeholders and contractual interfaces, with a proactive mandate for the Contractor to facilitate this collaboration. This is essential for projects involving staged works, utility relocation, or public-private partnerships where access to the Site or to the Contractor’s resources may be critical.

🕰️ Historical Context: Key Changes from 1999 to 2017

Feature	1999 Edition	2017 Edition
Clause Title	Co-operation	Co-operation
Language Style	General, high-level obligation to “allow appropriate opportunities”	Detailed obligations with a focus on coordination, shared use, and entitlement rights
Entitlement Framing	Instruction may be considered a Variation (and give rise to Cost) if it causes Unforeseeable Cost	Unforeseeable coordination causes trigger entitlement to EOT and/or Cost Plus Profit (clearly articulated)
Initiation Mechanism	Based on Contract specification or Engineer’s instruction	Based on Employer’s Requirements or Engineer’s instruction
Coordination Duty	General obligation to allow others to work	Explicit duty to allow work, share facilities, and proactively coordinate using reasonable endeavours

The 2017 update modernized the clause in response to feedback about increased project complexity. It not only clarifies what is expected of the Contractor but also strengthens the Contractor’s entitlement to compensation when coordination causes unforeseeable delays or costs. This aligns with global best practices of managing interface risk.

🧩 Clause Breakdown

🔹 1999 Edition Highlights (Clause 4.6):

“The Contractor shall, as specified in the Contract or as instructed by the Engineer, allow appropriate opportunities for carrying out work to:

• the Employer’s Personnel,
• any other contractors employed by the Employer,
• the personnel of any legally constituted public authorities, who may be employed in the execution on or near the Site of any work not included in the Contract.

Any such instruction shall constitute a Variation if and to the extent that it causes the Contractor to incur Unforeseeable Cost.”

Key Observations:

• The obligation to allow work is reactive—either through Contract provisions or Engineer instruction.
• Use of the word “appropriate opportunities” allows flexible interpretation.
• Cost recovery is only possible via classification as a Variation and requires proof of “Unforeseeable” conditions.

🔹 2017 Edition Enhancements (Clause 4.6):

“The Contractor shall, as specified in the Employer’s Requirements or as instructed by the Engineer:

• allow appropriate opportunities for carrying out work, and for the use of the Contractor’s Equipment, Temporary Works or access arrangements,
• for the Employer’s Personnel, any other contractors employed by the Employer, and the personnel of any legally constituted public authorities.

The Contractor shall use all reasonable endeavours to coordinate his operations with those of such persons. If the Contractor suffers delay and/or incurs Cost as a result of such coordination, and such delay and/or Cost was Unforeseeable, the Contractor shall be entitled to EOT and/or Cost Plus Profit in accordance with Sub-Clause 20.2.”

Key Enhancements:

• Clearly defines the entities for whom access or facilities must be provided.
• Introduces shared use of Contractor’s Equipment and Temporary Works.
• Adds a positive obligation to coordinate proactively.
• Establishes a dual entitlement to time and cost with profit when disruptions are Unforeseeable.

🔧 Real-Life Example (U.S. Context)

Consider a design-build project for a new urban highway interchange in New York:

• The Contractor must coordinate with local utilities (telecom, gas, water) to allow trenching in specific corridors.
• The Department of Transportation (acting as Employer) has a separate contract for installation of smart traffic infrastructure.
• Public authorities require intermittent access to inspect and approve works.

In the 1999 context, if an instruction causes delay and the cost is truly unforeseen, the Contractor may claim additional payment, but only for the cost—no automatic entitlement to profit.

In the 2017 context, if the need to coordinate was not specified in the Employer’s Requirements and leads to disruption or re-sequencing, the Contractor is clearly entitled to:

• Extension of Time if the works are delayed,
• Cost Plus Profit, covering additional resource usage, overtime, or inefficient working.

This significantly enhances risk clarity and allocates responsibility more equitably.

📌 Interacting Clauses

Clause 1.1 (Definitions): This clause provides foundational definitions essential to interpreting Clause 4.6. For example, “Unforeseeable” is defined as something not reasonably foreseeable by an experienced contractor at the Base Date, impacting whether a claim under Clause 4.6 is valid. “Cost” includes all expenditures reasonably incurred but excludes profit unless explicitly stated, which is pivotal when assessing compensation entitlements. “Contractor’s Equipment” refers to the tools and machines under the Contractor’s control that may be shared under Clause 4.6.

Clause 13.3 [Variation Procedure]: In the 1999 edition, any instruction requiring cooperation that incurs Unforeseeable Cost may be treated as a Variation. This clause lays out how such Variations are proposed, valued, and implemented, making it critical in disputes over whether such coordination constitutes additional work.

Clause 20.2 [Claims] (2017) or Clause 20.1 (1999): These clauses govern the formal claim submission process. Under the 2017 edition, Clause 4.6 specifically links to Clause 20.2 to allow EOT and Cost Plus Profit claims. Clause 20.1 in 1999 provides the general structure for claiming Cost or EOT due to instructions impacting work sequences.

Clause 4.20 [Progress Reports]: This clause mandates regular updates from the Contractor. It is a key tool for tracking the timing and impact of coordination issues, forming part of the evidentiary basis for claims made under Clause 4.6.

Clause 4.10 [Use of Site Data]: Site data disclosures may reveal known adjacent works or other contractors, impacting whether issues under Clause 4.6 were foreseeable. If data was incomplete or misleading, it could support an argument that delays or costs were Unforeseeable, thereby supporting a claim.

⚠️ Common Challenges & Solutions

Problem 1: Ambiguity around “appropriate opportunities” or the limits of “Contractor’s Equipment” usage.

• ✅ Solution: Define precise expectations in the Employer’s Requirements and refer to relevant technical schedules.

Problem 2: The Contractor claims coordination delays were Unforeseeable; the Employer disputes this.

• 🛠 Solution: Require interface risk assessments in Contractor’s proposal; document assumptions clearly.

Problem 3: Access conflicts lead to sequence disruption or health and safety issues.

• 🚧 Solution: Set up a Site Interface Management Plan (SIMP) as part of the contract documentation.

✏️ Clarity & Drafting Suggestions

• Vague Phrases such as “appropriate opportunities” or “reasonable endeavours” benefit from quantifiable metrics (e.g., defined access windows or coordination meetings).
• Employers should outline known coordination interfaces (e.g., named third parties, expected activities, timeline overlaps) in the Employer’s Requirements.
• The Contractor should propose interface buffers and allowances in its baseline programme and budget.
• Where access is recurring or involves shared use, consider appendices with detailed schedules.

Flowchart

Detailed Explanation of the Flowchart:

1. Start: The process begins when the Contractor receives an instruction from the Engineer for co-operation.
2. Receive Engineer’s Instruction for Co-operation: The Contractor receives an instruction from the Engineer to allow opportunities for work to other parties like the Employer’s Personnel, other contractors, or public authorities.
3. Check if Instruction Causes Unforeseeable Cost: The Contractor assesses whether the instruction from the Engineer leads to any unforeseeable costs.
   • Yes: If yes, the instruction is considered a Variation.
   • No: If no, the Contractor proceeds with the co-operation as instructed.
4. Instruction Constitutes a Variation: If the instruction leads to unforeseeable costs, it is considered a Variation, and the Contractor must submit a proposal for this Variation.
5. Proceed with Co-operation: The Contractor allows opportunities for work to the Employer’s Personnel, other contractors, and public authorities as per the Engineer’s instruction.
6. Submit Variation Proposal: If the instruction is a Variation, the Contractor submits a proposal outlining the changes, reasons, and potential impacts.
7. Allow Opportunities for Work to Employer’s Personnel, Other Contractors, Public Authorities: Whether the instruction is a Variation or not, the Contractor allows the specified opportunities for work.
8. Coordinate Activities with Other Contractors: The Contractor coordinates his activities with those of other contractors to the extent specified in the Employer’s Requirements.
9. Submit Required Contractor’s Documents to Engineer: If required, the Contractor submits any necessary documents to the Engineer as per the Employer’s Requirements.
10. End: The process concludes once all the steps are completed.

Sample Letters

Sample Letter 1: Request for Co-operation

[Contractor’s Company Letterhead]
[Date]

[Employer’s Name]
[Employer’s Address]

Subject: Request for Clarity on Co-operation as per Clause 4.6 of FIDIC Contract

Dear [Employer’s Name],

As we progress with the [Project Name], we seek your guidance on the expected co-operation under **Clause 4.6 Co-operation**. Specifically, we would like to understand how we are to co-ordinate our activities with other contractors or public authorities involved in the project.

Your prompt attention to this matter would be greatly appreciated.

Sincerely,
[Your Name]
[Your Position]

Sample Letter 2: Notification of Unforeseeable Costs

[Contractor’s Company Letterhead]
[Date]

[Employer’s Name]
[Engineer’s Name]
[Addresses]

Subject: Notification of Unforeseeable Costs under Clause 4.6 of FIDIC Contract

Dear [Employer’s and Engineer’s Names],

During the co-operation process with [Other Contractor/Public Authority], we have incurred Unforeseeable Costs not accounted for in the initial contract. As per **Clause 4.6 Co-operation**, we are notifying you of these costs and formally requesting a Variation to address them.

Attached are the details of the costs incurred. We request your urgent attention to this matter.

Sincerely,
[Your Name]
[Your Position]

Sample Letter 3: Employer’s Instruction for Co-operation

[Employer’s Company Letterhead]
[Date]

[Contractor’s Name]
[Contractor’s Address]

Subject: Instructions for Co-operation under Clause 4.6 of FIDIC Contract

Dear [Contractor’s Name],

As per **Clause 4.6 Co-operation**, we instruct you to co-operate with [Other Contractor/Public Authority] for [Specific Task]. Please ensure that you provide appropriate opportunities for carrying out this work, as stipulated in the clause.

Your co-operation is crucial for the smooth execution of the project.

Sincerely,
[Your Name]
[Your Position]

Checklists

1. Checklist to Aid in the Proficient Execution, Deployment, and Supervision of Clause 4.6 Co-operation

Task	Responsible Party	Deadline	Status Update	Documentation	Cost Estimate	Training Program	Ethical Considerations
Identify relevant parties	Project Manager	[Date]	[Status]	[Document Name]	[Cost]	[Training Name]	Fair selection of personnel
Establish communication lines	Communication Team	[Date]	[Status]	[Document Name]	[Cost]	[Training Name]	Transparent communication
Define roles & responsibilities	HR	[Date]	[Status]	[Document Name]	[Cost]	Orientation program	Equal opportunity for all
Integrate cooperation requirements	Planning Team	[Date]	[Status]	[Document Name]	[Cost]	[Training Name]	Adherence to project ethics
Monitor cooperation efforts	Quality Control	[Date]	[Status]	[Document Name]	[Cost]	Monitoring workshop	Ethical monitoring practices

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2. Checklist to Assist in Applying and Overseeing Clause 4.6 Co-operation

Task	Responsible Party	Deadline	Status Update	Documentation	Feedback Mechanism
Provide opportunities for Employer’s Personnel	Contractor	[Date]	[Status]	[Document Name]	[Feedback Channel]
Coordinate with other contractors	Contractor	[Date]	[Status]	[Document Name]	[Feedback Channel]
Facilitate work for public authorities	Contractor	[Date]	[Status]	[Document Name]	[Feedback Channel]
Address any arising conflicts	Mediation Team	[Date]	[Status]	[Document Name]	[Feedback Channel]
Review cooperation efforts	Review Team	[Date]	[Status]	[Document Name]	[Feedback Channel]

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3. Checklist to Guide and Monitor the Execution of Clause 4.6 Co-operation

Task	Responsible Party	Start Date	End Date	Monitoring Mechanism	Challenges	Solutions
Establish collaboration framework	Planning Team	[Start Date]	[End Date]	[Monitoring Tool]	[Challenge]	[Solution]
Train all parties on cooperation requirements	HR	[Start Date]	[End Date]	[Monitoring Tool]	[Challenge]	[Solution]
Regularly update on cooperation progress	Communication Team	[Start Date]	[End Date]	[Monitoring Tool]	[Challenge]	[Solution]
Address any technical concerns	Technical Team	[Start Date]	[End Date]	[Monitoring Tool]	[Challenge]	[Solution]
Evaluate the effectiveness of cooperation	Quality Control	[Start Date]	[End Date]	[Monitoring Tool]	[Challenge]	[Solution]

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These checklists serve as comprehensive guides to ensure the proficient execution, deployment, supervision, application, and monitoring of Clause 4.6 Co-operation. They emphasize collaboration, transparency, accountability, and ethical considerations.