A Practical Framework for Project Managers and Delay Analysts
Concurrent delay remains one of the most debated and most misunderstood issues in construction delay analysis. Despite decades of case law and guidance, there is still no single rule that resolves all concurrency disputes. Instead, outcomes often depend on how the analysis is framed, what question is being asked, and how closely the method reflects what actually happened on the project.
Two cases frequently cited together, Malmaison and Adyard, are often treated as competing authorities. In practice, this framing is misleading. Rather than offering mutually exclusive answers, these cases illustrate different analytical approaches, each suited to a different type of question.
Understanding this distinction is essential for project managers, engineers, and decision-makers responsible for Extension of Time (EOT) assessments.
What Is Concurrent Delay and Why Is It So Difficult?
At a basic level, concurrent delay arises when employer-risk and contractor-risk events affect the critical path during the same period. The challenge is rarely identifying overlap. The real difficulty lies in deciding what legal and contractual consequences should follow.
Courts have repeatedly resisted rigid definitions such as “true concurrency” or “dominant cause.” Instead, they focus on a simpler but more demanding enquiry:
What actually constrained completion on the project?
Malmaison and Adyard should be understood as tools for answering that question, not as rigid formulas to be applied mechanically.
The Malmaison Perspective: Completion as the Benchmark
The reasoning associated with Malmaison is often summarised as “time but no money.” At its core, it treats the contractual completion date as the reference point for analysis.
From this perspective:
- Concurrency is assessed by reference to simultaneous effects on completion, not merely overlapping activities.
- The existence of contractor delay does not automatically defeat entitlement to an EOT if an employer-risk event has also delayed completion.
- More than one effective cause can operate on the critical path at the same time.
This approach is closely linked to the prevention principle, which seeks to prevent an employer from benefiting from its own delaying acts by holding time “at large.”
Practical implications of a Malmaison-style analysis:
- An EOT is typically granted where employer and contractor delays run concurrently.
- Prolongation costs for that same period are generally not recoverable.
- Liquidated damages are often suspended during the period of concurrency.
Malmaison therefore frames concurrency primarily as a question of entitlement at completion, rather than as a purely scheduling exercise.
The Adyard Perspective: Forecast and Progressive Causation
Adyard is often interpreted as applying a stricter causation test by shifting the focus to the then-forecast completion date.
The key question becomes:
Did the employer event actually push completion later than it was already forecast to finish due to contractor delay?
Under this approach:
- Delay is measured against the critical path as it existed at the time of the event.
- If the project was already forecast to finish late due to contractor delay, an employer event occurring during that period may justify no EOT unless it demonstrably extends the forecast completion.
- Greater emphasis is placed on programme logic, sequencing, and contemporaneous forecasts.
This introduces a more explicit “but-for” causation test, asking whether the employer event truly changed the project’s predicted outcome.
Malmaison vs Adyard: Analytical Comparison
| Aspect | Malmaison-Style Analysis | Adyard-Style Analysis |
| Primary reference point | Contractual completion date | Then-forecast completion date |
| View of concurrency | Multiple effective causes may coexist | Focus on whether employer event adds delay |
| Causation test | Broad, prevention-oriented | Stricter “but-for” causation |
| Role of contractor delay | Does not automatically defeat EOT | May defeat EOT if already driving delay |
| Programme emphasis | Secondary to factual impact | Central to contemporaneous assessment |
| Typical EOT outcome | EOT granted during concurrency | EOT only if forecast completion moves |
| Commercial consequence | “Time but no money” | LDs may continue if contractor delay dominates |
This comparison highlights why disagreements about concurrency often arise. The two approaches are answering different analytical questions, not applying different rules.
Chronology and Causation: Different Questions, Not Different Answers
Seen clearly, Malmaison and Adyard are not contradictory. They simply address different moments in time.
- Malmaison asks:
Did this event delay completion, even if other delays were present? - Adyard asks:
Did this event change the project’s forecast completion at the time it occurred?
Problems arise not because one approach is used, but because chronology is mistaken for causation, or because a method is applied without regard to the question being asked.
Chronology vs Causation: Common Pitfalls in Practice
| Issue | Risk if Misapplied | Better Analytical Focus |
| First-in-time logic | Employer delay ignored because it occurred “second” | Assess actual critical impact |
| Programme-driven models | Software logic overrides facts | Treat programmes as evidence |
| Label-based reasoning | “True concurrency” replaces factual analysis | Focus on what constrained completion |
| Baseline programme rigidity | Resequencing rights overlooked | Evaluate real-time project behaviour |
| Black-box expert reports | Conclusions cannot be tested | Demand transparent causation logic |
These pitfalls explain why concurrency disputes so often become entrenched. The analysis becomes method-driven rather than fact-driven.
Programmes Are Evidence, Not Obligations
A recurring mistake in concurrency disputes is the over-legalisation of baseline programmes.
Courts have repeatedly recognised that:
- the contractor’s obligation is to achieve completion by the contractual date;
- the contractor may resequence works;
- deviation from a baseline programme does not, by itself, establish culpable delay.
Treating programmes as legally binding instruments risks allowing scheduling software to override contractual risk allocation and factual reality.
Key Takeaways for Project Decision-Makers
Rigid analytical shortcuts can easily:
- ignore genuine employer-caused delay,
- over-emphasise contractor sequencing choices,
- misrepresent what actually constrained completion.
Three practical priorities stand out:
- Be clear about the question
Is the analysis assessing contemporaneous project control or retrospective entitlement? - Focus on facts, not labels
Malmaison and Adyard are tools, not answers. - Resist black-box conclusions
Demand transparency in how causation has been tested.
Final Thought
When understood properly, Malmaison and Adyard are not opposing camps. They form a spectrum of analytical reasoning that helps practitioners navigate one of the most complex areas of construction delay analysis.
Applied thoughtfully, they move beyond legal buzzwords and become practical tools, supporting balanced and defensible outcomes on extensions of time and liquidated damages in complex construction projects.
References
- Henry Boot Construction (UK) Ltd v Malmaison Hotel (Manchester) Ltd 70 Con LR 32 (TCC). https://www.bailii.org/ew/cases/EWCA/Civ/2005/814.html
- Adyard Abu Dhabi v SD Marine Services LLC EWHC 848 (Comm); 136 Con LR 190. https://www.casemine.com/judgement/uk/5a8ff7dd60d03e7f57eb288b
- Walter Lilly & Co Ltd v Giles Patrick Cyril Mackay and another EWHC 1773 (TCC).
- City Inn Ltd v Shepherd Construction Ltd CSIH 68; 2010 SLT 1049. https://www.bailii.org/scot/cases/ScotCS/2010/2010CSIH68.html
