In the dynamic world of construction, change is inevitable. Whether due to evolving client requirements, unforeseen site conditions, or regulatory amendments, and coordination complexities all contribute to projects deviating from their originally contracted scope. Among the mechanisms designed to manage such deviations, Variation Orders and Extensions of Time (EOT) claims are the most significant. When poorly administered, they often become catalysts for disputes, financial pressure, and strained relationships. When properly managed, they promote fairness, transparency, and contractual certainty.

This article explores how to effectively manage variations and EOT claims and highlights best practices to avoid common pitfalls.

Understanding Variation Orders

A Variation Order (or Change Order) “can be initiated by the employer altering the scope or increasing the volume of an item under the existing scope. In working on the project, the contractor may also discover that changes to contractual requirements are necessary, or it might make a submission for change that could benefit the parties by reducing the timescale, creating a more durable product or lowering the cost of a project element or elements.”^[1]Change control and management, RICS practice information, UK 1st edition, January 2021, 1 April 2021

Key Point: Not all variations lead to delays or cost increases / decreases, but many do—especially when they affect critical path activities.

Extension of Time (EOT) Claims

An EOT Claim is a contractual entitlement allowing the contractor for additional time to complete the project due to excusable delays beyond its control. Typical triggers include, without limitation:

• Approved variation orders
• Unforeseen site conditions
• Force majeure events
• Delays caused by the employer or third parties
• Design Changes
• Late approvals
• Delayed access

EOTs protect contractors from liquidated damages where delays are not their fault. At the same time, they preserve the employer’s right to enforce liquidated damages by maintaining a valid completion date and avoiding situations where time becomes “at large.”

Example: A design change requiring structural rework may necessitate an EOT to accommodate the additional work.

The Interlink Between Variations and EOTs

Variations and EOTs are often interdependent. A variation that significantly increases the scope of work may justify an EOT, but only if it delays completion. Variations do not automatically entitle contractors to additional time; they must demonstrate actual impact on the critical path.

Contractors should:

• Assess each variation for time impact using Critical Path Method CPM) analysis or programme updates.
• Submit EOT claims with proper substantiation, including affected activities, delay analysis, and supporting records.
• Maintain contemporaneous evidence (site diaries, correspondence, and revised schedules).

This structured approach aligns modern delay jurisprudence, where courts focus on causation and critical‑path impact when determining entitlement.

Best Practice: Contractors should assess each variation for time impact and submit EOT claims with supporting documentation as needed.

Prolongation Costs and Overheads

When a variation results in additional time, supported by an EOT, the contractor may be entitled to recover the prolongation costs, which arise due to the extended presence on site.

The prolongation costs usually include indirect costs, such as:

• Site overheads: supervision, welfare facilities, security, utilities, temporary works.
• Head office overheads: management salaries, administrative support, insurance, rent allocations.
• Equipment/material costs: storage, rental extensions, protective measures.
• Financial charges and interest.

However, a central valuation principle applies:

Contractors must not recover the same overhead costs twice.

This risk of double recovery commonly arises when:

• overheads are embedded within the rates for varied work; and
• the contractor separately claims prolongation costs for the same period

To avoid disputes:

• overheads included within contract rates must not be reclaimed as prolongation; and
• prolongation claims must be supported by evidence showing the overheads arise solely due to the delay resulting from the variation.

The risk of double recovery is one of the most common sources of dispute in variation‑EOT‑prolongation scenarios. Contract administrators consistently require contractors to demonstrate distinct, additional, delay‑related overheads and ensure they are not already embedded in the contemporaneously agreed rates or prices for varied work.

Caution: Avoid double counting overheads—claiming the same costs under both the base contract and the variation. This is a common source of dispute.

Concurrent Delays

The SCL Delay and Disruption Protocol defines concurrent delay as circumstances in which an Employer Risk Event and a Contractor Risk Event both operate as effective causes of critical delay to completion, with their effects felt at the same time. It distinguishes:

• True concurrency: events occur simultaneously
• Functional concurrency: different events whose effects overlap on the critical path

This definition is supported by leading cases:

• Adyard Abu Dhabi v SD Marine Services: defined concurrent delay as overlapping delay events with roughly equal causal impact.^[2][2011] EWHC 848
• Royal Brompton Hospital NHS Trust v Hammond (No. 7): emphasised that concurrency arises where either event alone would have delayed completion.^[3]76 Con LR 148 ; EWCA Civ 206

The SCL Protocol adopts a principled approach:

• EOT entitlement: where employer and contractor delays are concurrent, the contractor’s culpable delay does not reduce the EOT due for the employer‑risk event
• Prolongation entitlement: however, even if EOT is granted, prolongation costs are not automatically recoverable

To recover prolongation costs, the contractor must prove that:

• The additional costs stem from the employer‑risk delay alone
• The contractor’s own delay would not have caused the same prolongation

This results in a “separation of cause” requirement.

Recent case law^[4]Key authorities: City Inn Ltd v Shepherd Construction Ltd (Scotland), United Constructors, LLC v United States (2010), Catel, Inc. v United States, H Fairweather & Co Ltd v Wandsworth LBC shows growing judicial acceptance of apportioning concurrent delays where:

• causes are separable,
• delay responsibility is measurable, and
• modern CPM scheduling allows reliable allocation of impact

Courts consistently emphasise that:

• Contract provisions override default legal principles;
• Silence in the contract leaves the matter to established common‑law doctrines (often denying damages for concurrency);
• Clear contractual clauses (e.g., NEC, FIDIC amendments) can dictate how concurrency is to be handled.

Best Practices for Managing Variations and EOTs

1. Understand the Contract: Know your rights and obligations under the contract.
2. Document Everything: Maintain detailed records of instructions, approvals, costs, and delays.
3. Communicate Early and Often: Notify the employer of potential delays or cost impacts as soon as they arise.
4. Use Clear Clauses: Include provisions for variation approval, EOT procedures, and prolongation costs.
5. Avoid Double Dipping: Ensure overheads are allocated transparently and only once.
6. Leverage Technology: Use project management tools to track changes, costs, and timelines in real time.

Conclusion

Variations and EOTs are not mere administrative procedures; they are core mechanisms for managing change in construction projects. When handled with clarity, rigorous documentation, transparent cost allocation, and timely communication, they protect the rights of all parties and contribute to effective project delivery.

A major area of risk is overstating or duplicating overhead costs, especially where both varied work and prolongation claims touch the same period. Likewise, entitlement depends on demonstrating causation: an EOT will only follow where the variation extends the critical path, and compensability will depend on distinguishing employer‑driven delays from contractor‑driven ones—particularly in scenarios involving concurrency.

Thus, effective management of variations and EOTs requires disciplined documentation, clear contractual mechanisms, careful impact analysis, and vigilant protection against overstated or duplicated claims. By approaching these elements with clarity and fairness, project teams can mitigate conflict, preserve contractual integrity, and ensure that change is managed transparently and defensibly.

About the author

Hilal Itani is a Partner at HKA’s Riyadh office, Saudi Arabia, bringing over 24 years of specialized experience in claims preparation, defence, and alternative dispute resolution. Recognized as one of the few dual experts in the region with deep expertise in both delay and quantum assessments, Hilal is trusted to deliver strategic solutions for some of the most complex and high-stakes projects in the Kingdom. 

In his leadership role, Hilal ensures that the Riyadh office operates in full alignment with HKA’s global strategic objectives, while driving excellence in service delivery for major clients and critical accounts. He has an exceptional track record of managing disputes on multi-billion-dollar projects, where his ability to navigate intricate contractual frameworks and deliver robust delay and quantum analyses has been instrumental in achieving successful outcomes for stakeholders. 

Hilal is a certified Expert Witness by RICS and has provided expert testimony in cases across diverse sectors. His analytical rigor and structured methodologies have consistently resolved disputes involving large-scale projects and complex stakeholder environments, reinforcing his reputation as a trusted advisor for high-stakes matters. 

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