The NEC4 8-Week Time Bar: Why Clause 61.3 is the Most Expensive Trap in Construction

1. What Clause 61.3 Actually Says

Clause 61.3 states: "The Contractor notifies the Project Manager of an event which has happened or which is expected to happen as a compensation event. If the Contractor does not notify a compensation event within 8 weeks of becoming aware of the event, the Contractor is not entitled to a change in the Prices or the Completion Date unless the Project Manager should have notified the event to the Contractor."

Let me translate that: if you miss the 8-week deadline, you lose. Permanently. Irrevocably. No matter how valid the claim, no matter how much money is at stake.

2. When Does the 8-Week Clock Start?

This is where most mistakes happen. The clock starts when the Contractor becomes aware of the event — or when they should reasonably have become aware.

This is an objective test. "I didn't realise it was a compensation event" is not a defence. If a site supervisor saw the ground condition, if a quantity surveyor received the variation instruction, if a project manager attended the meeting where the change was discussed — the clock is ticking.

Some practical examples:

• A PM verbally instructs a change on 1 March. The written confirmation arrives on 15 March. Clock started on 1 March (verbal instruction), not 15 March.
• A site condition is discovered during excavation on 10 April. The project team discusses it at the weekly meeting on 14 April. Clock started on 10 April (discovery), not 14 April.
• The Employer fails to provide access by 1 May per the Accepted Programme. Clock started on 1 May.

3. The Real Cost of Missing the Deadline

Over the years, I've seen the same pattern repeat: a contractor has a valid compensation event, the project team knows about it, but the formal notification gets delayed while someone "gathers cost information" or "waits for the right moment."

By the time the quotation is ready, the 8-week window has closed. The PM rejects the notification. The contractor loses the entitlement. The costs — sometimes hundreds of thousands — are never recovered.

The saddest part? It's completely avoidable. Clause 61.3 only requires notificationwithin 8 weeks, not a full quotation. You can notify with minimal detail and provide the full assessment later. But most contractors don't realise this until it's too late.

4. How to Protect Your Entitlement

1. Notify early, notify often. If you suspect an event might be a CE, notify immediately. A brief email is enough to start the process. You can always supplement with details later.
2. Track potential CEs weekly. Make "compensation event review" a standing agenda item at every site meeting. Flag anything that might qualify under Clause 60.1.
3. Use the Early Warning procedure. Clause 16 early warnings can alert the PM to potential CEs before they crystallise. This protects your position even if the CE notification comes later.
4. Document everything. If a PM gives a verbal instruction, confirm it in writing the same day. This starts the clock on your entitlement, and also protects you if the PM later denies giving the instruction.
5. Don't wait for cost data. Notify first, price second. The 8-week clock only applies to notification, not quotation submission.

5. Free Tools to Help

• Search Clause 61.3 — Full text with practical commentary
• CE Notification Tool — AI-drafted notification in seconds
• Early Warning Generator — Clause 16 notices