The NEC eight week rule, explained with examples

The eight week rule is the sharpest edge in NEC. Put simply: if the contractor did not notify a compensation event within eight weeks of becoming aware of the event, the contractor is not entitled to a change in the prices, the completion date or a key date, unless the project manager should have notified it and did not.

That is a genuine time bar. Not a procedural irritation, not something to be tidied up at the final account. A meritorious claim, properly valued, can be worth nothing because a notification went in at nine weeks. This is the single biggest difference between NEC and standard JCT for the average contractor, and it is why NEC rewards administration in a way JCT does not.

When does the clock start?

Not at the instruction. Not at the point you finish assessing the cost. The clock runs from when the contractor became aware of the event.

This is deliberately a factual test about knowledge, and it is generous to nobody. Awareness typically sits with the site team, on the day, in the moment they encounter the unforeseen condition or receive the instruction. It does not wait for the commercial team to hear about it.

That gap between site awareness and commercial awareness is where most eight week failures are born. The site knew on the 3rd. The surveyor found out on the 40th, when it surfaced in a progress meeting. By then five and a half weeks are gone and nobody realises a clock has been running.

The exception, and why you should not rely on it

The bar does not apply where the project manager was required to notify the event and failed to do so. NEC requires the project manager to notify compensation events arising from their own instructions and from certain other matters, so for those categories the contractor’s late notification is not fatal.

In practice this exception is narrower than contractors hope. It turns on which category the event falls into, and arguing about categories after the fact is a much weaker position than simply having notified on time. Treating the exception as a safety net is how claims get lost.

Early warnings are a separate duty, and they are not notifications

This confusion costs people money. An early warning and a compensation event notification are different instruments with different purposes and different consequences.

The early warning duty requires each party to notify the other as soon as they become aware of any matter which could increase the prices, delay completion, delay a key date or impair performance. It exists to get the parties into a room while the problem is still manageable.

Raising an early warning does not notify a compensation event. It is entirely possible to have flagged a problem diligently through the early warning process, attended the risk reduction meetings, and still be time barred, because you never served the notification that clause 61.3 requires.

Failing to give an early warning has its own consequence: the event can be assessed as if the warning had been given, which typically reduces what you recover.

Three worked examples

Example one: the obstruction. On 4 March the groundworks gang hits an unrecorded concrete obstruction. The site supervisor photographs it in the group chat that morning. This is the date of awareness. The eight week clock expires around 29 April. The surveyor first hears about it at the monthly meeting on 26 March and assumes there is time. The notification goes in on 12 May, chasing a quotation. It is late. Entitlement to additional time and money is likely gone, and the fact everyone knew about the obstruction from the photographs does not fix it, because knowledge is not notification.

Example two: the instruction. The project manager instructs a change to a specification on 10 April. This is an instruction the project manager is required to notify as a compensation event. If they do not, the contractor’s later notification is protected by the exception. Note how much better it would still be to have notified on 11 April: the contractor spends nothing arguing about which category the event sits in.

Example three: the creeping event. Information is late. Not dramatically, just persistently, from early February onwards. There is no single moment of awareness, which is precisely what makes this dangerous. The contractor waits for a clear trigger, the trigger never arrives, and by the time the cumulative effect is undeniable in June the earliest and most valuable parts of the claim are well outside eight weeks. Where an event accrues gradually, notify early and notify the pattern rather than waiting for certainty.

What this means for your records

The eight week rule turns your site diary into a commercial instrument, because the date of awareness is a question of fact that your own records will be used to answer.

Two consequences follow, and they pull in opposite directions.

Good records help you establish awareness on your terms, and they let you find events before the clock runs out. Bad records let the other side argue you were aware earlier than you say, using your own photographs against you.

The photograph timestamped 4 March that nobody actioned is the thing that proves you were aware on 4 March. This is not an argument for recording less. It is an argument for having a process that reads the record and acts on it, because the evidence of awareness is being created either way.

The practical fix

The eight week rule punishes the gap between what the site knows and what the commercial team knows. Everything useful you can do is aimed at closing that gap.

• Treat the site group chat as an event feed, not chatter. Most awareness starts there.
• Run a compensation event register with a notified date and a clock, reviewed weekly, not monthly. A monthly cycle burns a quarter of your window every time it turns.
• Notify early and notify thinly. A notification does not require a quotation attached; it requires you to have notified.
• When in doubt about whether something is an event, notify. The cost of an unnecessary notification is a conversation. The cost of a late one is the claim.
• Read your Z clauses. Amendments routinely change these timescales.

Construction Metric was built around exactly this gap: it captures what the site says as it is said, so the awareness date is on the record and the commercial team can see it the same evening rather than at the next monthly meeting. See how it works, or the NEC explainer for how the wider machinery fits together.