Delay claims usually fail for a straightforward reason: the delay was not analysed and recorded properly as it happened.
The work may genuinely have been held up. The client’s instruction may have arrived late. Access may have been unavailable. Design information may have been missing. But a contractor still needs to answer two questions:
- Was the delay on the critical path?
- Can you demonstrate it with contemporaneous records?
A narrative written at final account stage is not enough. You need the contract, the Accepted Programme and the records to tell the same story.
This matters particularly under NEC4. Entitlement comes from the contract. Quantification comes from analysing the effect on the Accepted Programme and the Defined Cost. They are connected, but they are not the same exercise.
Entitlement is not quantification
Under NEC4, a contractor’s entitlement may arise from a compensation event under clause 60.1. Examples include:
- a Client instruction changing the Scope;
- a failure to provide something by a stated date;
- a Project Manager failing to act within the contract period;
- the Project Manager withholding acceptance for a reason not permitted by the contract.
The contractor must normally notify a compensation event within eight weeks of becoming aware that it has happened. Missing the clause 61.3 time bar can remove entitlement to additional time and money, subject to the contract wording and applicable exceptions.
The notification establishes the contractual route. It does not prove the delay period.
Quantification requires you to assess what the event did to the programme. Under NEC4, that assessment is generally prospective. You forecast the effect of the event against the Accepted Programme current at the relevant dividing date.
As the BHD guide to NEC4 compensation events explains, the programme demonstrates when the effect occurs. The cost assessment demonstrates what that effect costs.
Why the Accepted Programme matters
The Accepted Programme is the anchor for NEC delay analysis. It sets out the planned sequence, logic, progress, float and planned Completion.
Clause 32 also requires the Contractor to keep the programme current with actual progress and the effects of implemented compensation events.
An out-of-date programme is one of the most common reasons a delay position collapses. If the programme does not reflect actual progress, the Project Manager may assess the event using its own assumptions. That creates risk precisely when you need a clear contractual basis.
7 mistakes that weaken a contractor’s delay case
1. Notifying the event late
Do not wait until the full impact is known before notifying.
The eight-week period runs from awareness that the compensation event has happened. It does not necessarily start when the final cost or delay becomes certain.
A late notification gives the Client or Project Manager an immediate procedural argument. It also suggests that your team was managing the issue retrospectively rather than in real time.
Better control: maintain an event log with the date of awareness, contractual trigger, notification date and time-bar deadline. When in doubt, take early advice and notify clearly.
2. Treating an early warning as an extension-of-time notification
An early warning identifies a matter that could affect cost, time, Key Dates or performance. It gives the parties an opportunity to mitigate the risk.
A compensation event notification says that a contractual event has occurred and starts the assessment process.
They are not interchangeable.
The NEC4 early warning process should be linked to your compensation event records, but one does not replace the other.
Better control: record the early warning, then issue a separate compensation event notification when the contractual event occurs. Keep both documents in the same event file.
3. Using the wrong or outdated baseline
A contractor may rely on the original tender programme even though the Accepted Programme has changed several times. That weakens the analysis.
Delay must be assessed against the programme that reflects the project position at the relevant time, not the programme that produces the most attractive result.
Better control: update the Accepted Programme at the required intervals. Include actual progress, agreed changes, implemented compensation events, remaining logic and current constraints.
If the programme is not accepted, or the Project Manager has made its own assessment, obtain specialist advice before presenting a delay position as certain.
4. Claiming global or total delay
A global delay claim says, in effect, that several problems caused the overall overrun. It does not properly separate the effect of each event.
That approach makes it difficult to establish causation. It may also include contractor-risk delay, poor productivity or sequencing issues that cannot be recovered.
Better control: analyse delay event by event. For each event, identify the affected activity, the critical path at the time, the forecast completion effect and any mitigation considered.
Truth is more useful than presentation. If one event caused no movement to planned Completion, say so.
5. Changing the critical path without explaining why
The critical path can move during a project. That is normal. The problem arises when the analysis simply shows a different critical path without explaining the change.
The Client or Project Manager will ask whether the event caused the movement or whether the path changed because of contractor progress, resequencing, late procurement or another event.
Better control: identify the critical path at the time of each event. Explain changes between programme updates and distinguish Client-risk delay from contractor-risk delay.
A critical path is not a label to apply after the event. It is a position you need to demonstrate from the programme records.
6. Relying on reconstructed records
A programme rebuilt months later is weaker than an update produced during the work. The same applies to recreated site diaries, retrospective labour allocations and unsupported explanations of access or productivity.
Useful contemporaneous records include:
- dated site diaries and progress records;
- programme updates and accepted submissions;
- allocation sheets and labour returns;
- plant records and standing-time records;
- delivery tickets and material records;
- weather records;
- site instructions and correspondence;
- meeting minutes;
- photographs;
- access and availability logs;
- a live change and risk register.
Records created as the work happens carry more weight because they show what the project team knew and did at the time.
Better control: create an event-by-event delay file containing the notification, programme extract, relevant records, correspondence, mitigation actions and current assessment.
7. Separating the delay position from the cost position
An extension of time without the associated time-related cost recovery leaves money on the table. A cost claim without a programme basis is exposed.
Time-related preliminaries, prolonged site management, plant standing time, supervision and other costs need a clear link to the delay period and the contractual assessment.
Do not leave forensic analysis until the final account. By then, records may be missing, people may have moved on and the project history may be disputed.
Better control: forecast the time-related cost consequence alongside the time impact. Keep the programme, compensation event register, cost forecast and records aligned.
Which delay analysis method should you use?
The right method depends on the contract, available records and when you are carrying out the analysis. No method rescues a lack of evidence.
| Method | When it is useful | Main weakness |
|---|---|---|
| As-planned vs as-built | Comparing the original plan with actual progress at or after completion. | Shows overall movement but not always causation or responsibility. |
| Impacted as-planned | Testing the effect of a delay event against an early baseline. | Becomes weaker as the project diverges from the original plan. |
| Time slice or windows analysis | Reviewing delay period by period using successive programme updates. | Requires reliable updates and can become detailed and expensive. |
| Collapsed as-built | Removing alleged delay events from the as-built programme to test a hypothetical completion date. | Highly retrospective and exposed to assumptions about logic and concurrency. |
For NEC4 compensation events, a prospective time impact assessment using the Accepted Programme at the dividing date is generally the most suitable approach. It asks what the event was forecast to do, rather than reconstructing the project entirely with hindsight.
Retrospective analysis still has a place in disputes and complex delay assessments. It is legitimate, but usually weaker, more expensive and more open to challenge.
Practical controls that protect your position
A proportionate project controls process should include:
- a current Accepted Programme;
- an event-by-event delay file;
- a review of delay at every programme update;
- the critical path identified at the time of each event;
- linked early warning, change and compensation event registers;
- records of mitigation considered and implemented;
- a forecast of time-related cost alongside time impact.
Do not build systems for projects many times larger than your own. Use controls your site and commercial teams can maintain consistently.
How BHD Limited supports contractors
BHD’s Planning service line supports contractors with baseline and progress programmes, delay analysis, extensions of time support and planning consultancy.
We work alongside the commercial position so that cost and time tell the same story. That includes linking programme effects to compensation event management, NEC contract administration and practical project controls for contractors.
BHD Commercial's team brings 25 years' experience across construction, defence and infrastructure. Our team are members of the relevant professional body.
We support contractors across the UK, with West Midlands roots, a London head office at 66 Paul Street, London EC2A 4NA, and a Wolverhampton regional office at 4-5 Victoria Square, I11, Wolverhampton, WV1 1LD.
Frequently asked questions
What is the difference between a delay claim and an extension of time?
A delay claim usually describes the cause, effect and consequences of delay. An extension of time changes the contractual completion obligation.
Under NEC4, the adjustment to Completion normally arises through the compensation event process. You must establish entitlement under the contract and then demonstrate the effect on the Accepted Programme.
How long do I have to notify a compensation event under NEC4?
Under the standard NEC4 ECC wording, a Contractor-notified compensation event must normally be notified within eight weeks of becoming aware that it has happened.
Check the signed contract, amendments and Z clauses. A late notification can remove rights to additional time and money.
Can I claim delay costs without an extension of time?
Potentially, depending on the contract and the event. Some events may create additional cost without delaying planned Completion. However, time-related costs still need a sound programme and causation basis.
Do not assume that a cost claim succeeds simply because the project finished late.
What delay analysis method should I use?
For an NEC4 compensation event, start with a prospective time impact assessment against the current Accepted Programme. For a dispute or completed project, windows analysis or another retrospective method may be appropriate.
The records and contractual mechanism should determine the method, not the other way around.
What if my programme is out of date?
Do not ignore the problem. Establish what programme was last accepted, what progress had occurred and what events affected the position before the relevant dividing date.
An out-of-date programme does not automatically end your case, but it increases exposure and may allow the Project Manager to make its own assessment.
Do I need a planner as well as a quantity surveyor?
Often, yes. The planner tests sequence, logic, progress and critical path. The quantity surveyor tests entitlement, Defined Cost and commercial recovery.
The strongest position comes when both disciplines work from the same event record. A programme without commercial analysis is incomplete. A cost claim without programme evidence is vulnerable.
Conclusion
Delay analysis works best when it starts early.
Notify the event. Keep the Accepted Programme current. Record what happened as it happened. Analyse the critical path at the time. Link the delay to its cost consequence.
Do not wait until final account to discover that the records are incomplete.
If you have a live delay issue, BHD’s free Commercial Health Check provides an initial review of what is supportable, what is exposed and what can still be done. We will give you a straight view and a plan you can act on.