Extension of Time Too Late? Time Bars Under NZS 3910 NZ

Steve Parker
Jul 6
10 min read

Updated: 3 days ago

Told your extension of time claim is too late under NZS 3910? A missed 20-working-day notice is not always fatal. Here is what still gives a late EOT life in NZ.

By Steve Parker · Trueworks · NZ construction estimation · 8 min

Being told your extension-of-time claim is "too late" is not the same as it being dead. Under NZS 3910 the certifier is "not bound to" grant a late EOT — but is still required to exercise judgement reasonably and in good faith.

What you'll learn

Why the 20-working-day notice window is a default, not always a hard cut-off
When Special Conditions turn that window into a strict condition precedent that does kill a late claim
How the Construction Contracts Act 2002 gives you payment and adjudication rights the contract's time bar cannot touch

Quick answer: A late extension-of-time claim under NZS 3910 is not automatically time-barred. The standard §10 wording requires notice within 20 working days "or as soon as reasonably practicable thereafter", and says the certifier is "not bound to" grant an EOT that was not properly notified — but the certifier must still exercise judgement reasonably and in good faith. So a late claim survives or dies on three things: the exact contract wording, the prejudice your delay caused, and whether the Special Conditions hardened the deadline into a strict condition precedent. Separately, the Construction Contracts Act 2002 gives you statutory payment rights and fast adjudication that do not depend on the contract's EOT time bar. This is general information, not legal advice.

"Too late" is an opening position, not a verdict

When a Contract Administrator or certifier writes back that your extension-of-time claim missed the notice deadline, that is the start of the conversation, not the end of it. The standard form of NZS 3910 does not say a late claim is void. It sets a notice window — commonly 20 working days after the contractor becomes aware of the delaying event — and then adds the words that change everything: notice should be given within that window "or as soon as reasonably practicable thereafter".

That phrase exists because real Auckland jobs do not pause for paperwork. A subcontractor on a Penrose fit-out who hits an unexpected service run, or a piling crew in Albany who find the ground is not what the geotech report promised, is dealing with the problem on site first and the notice second. The standard recognises that. The deadline is a default and a discipline, not an automatic guillotine.

What the standard does say is that the certifier is "not bound to" grant an EOT that was not notified in time. "Not bound to" is permissive language, not prohibitive. It gives the certifier a discretion to decline — it does not order them to. And under NZS 3910 the Independent Certifier (the role split out from the old Engineer to the Contract in the 2023 edition) must exercise that discretion reasonably and in good faith. A blanket "you were late, so no" without engaging with the merits is itself open to challenge.

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What separates a late claim that lives from one that dies

The difference is rarely the calendar alone. It is whether your late notice actually harmed the other side's ability to manage the delay.

A certifier weighing a late EOT will look at prejudice. If you notified the delaying event two weeks after the window but the Principal lost nothing — they could not have mitigated the ground conditions or the late instruction any sooner, and your records still clearly establish cause and effect — the case for declining purely on timing is weak. If, by contrast, your silence meant the Principal kept paying for resources they would have stood down, or lost a chance to re-sequence the works, the late notice has caused real harm and the discretion to decline is far stronger.

The second factor is evidence. A late claim with a clean contemporaneous record — site diaries, dated photographs, the instruction or RFI that triggered the delay, programme impact shown against the baseline — is in a different league to a late claim reconstructed from memory months later. Lateness plus thin records is the combination that gets claims thrown out. Lateness plus a watertight causal chain is recoverable far more often than contractors assume.

This is also where the mechanics matter. If you are unsure exactly how the notice and assessment process is meant to run in the first place, read the §10 extension-of-time notice mechanics — that post covers the on-time process step by step. This post is about the harder question: what happens when you have already missed it.

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The clause that genuinely can kill a late claim

There is one way a late EOT really does become dead on arrival, and it is not in the standard NZS 3910 wording — it is in the Special Conditions.

NZS 3910 is a base contract that almost every Principal amends. The Special Conditions sit on top of the General Conditions and override them where they conflict. A well-advised Principal will often redraft the EOT clause to convert the soft "or as soon as reasonably practicable thereafter" default into a strict condition precedent: wording to the effect that if notice is not given within the stated period, the contractor's entitlement to an EOT (and sometimes to associated prolongation cost) is lost entirely. Courts will generally hold a contractor to clear condition-precedent wording, because both parties signed up to it.

That is the difference between "the certifier is not bound to grant it" (a discretion you can argue against) and "the contractor shall not be entitled" (a bar with no discretion left to exercise). The first leaves room. The second usually does not. So the first document to read when you are told your claim is too late is not the General Conditions — it is the Special Conditions, to see whether the deadline was hardened. For how these amendments routinely shift risk onto the contractor, see how Special Conditions shift risk.

A practical warning for subcontractors: your subcontract often mirrors the head contract's timing, sometimes with a shorter window, so the head contractor can pass claims up before their own deadline expires. Check the back-to-back clauses, because a deadline you never noticed in the head contract may bind you twice over.

The statutory backstop the time bar cannot reach

Here is the part that gets overlooked when everyone is arguing about the EOT clause. The contract's time bar governs time — your entitlement to more days on the programme and relief from liquidated damages. It does not govern your right to be paid for work you have actually done.

The Construction Contracts Act 2002 runs on a separate track. If you submit a valid payment claim and the other party does not respond with a compliant payment schedule by the due date, they can become liable for the full amount claimed regardless of any contractual notice dispute. The Act also gives you adjudication — a fast, statutory route to a binding interim decision — that does not wait on the EOT argument being resolved. And pay-when-paid clauses are void, so a subcontractor cannot be told their payment depends on the head contractor first being paid.

This matters because the two issues are routinely confused on site. A certifier might be entitled to decline a late EOT under a hardened Special Condition, yet you may still have a live, enforceable claim for the value of the variation work itself under the CCA. Losing the days does not automatically mean losing the payment. Treat the time claim and the payment claim as two distinct exercises, each with its own deadlines and its own remedies.

On-time EOT vs late EOT — what each gives you

| | On-time EOT (within the §10 window) | Late EOT (after the window) | |---|---|---| | Entitlement | Assessed on the merits in the normal way | Survives only if wording, prejudice and records support it | | Certifier's role | Must assess and certify reasonably and in good faith | "Not bound to" grant it, but discretion must still be exercised reasonably and in good faith | | What strengthens it | Clear cause-and-effect, programme impact shown | Low/no prejudice to the Principal, strong contemporaneous records, notice "as soon as reasonably practicable" after the event | | What weakens or kills it | Vague records, no programme link | Demonstrable prejudice; thin evidence; and decisively, a Special Condition making the deadline a strict condition precedent ("shall not be entitled") | | Payment position | Variation valued and paid under the contract | Payment for the work may still be recoverable under the Construction Contracts Act 2002, independent of the time bar |

What to do when you are told it is too late

Read the Special Conditions first, not the General Conditions. Find the exact EOT clause and check whether it says the certifier is "not bound to" grant (discretion remains) or that the contractor "shall not be entitled" (a strict condition precedent). This single distinction shapes everything that follows.
Reconstruct the timeline honestly. When did you become aware of the delaying event, and when did you give notice? If the gap is short and explainable, "as soon as reasonably practicable thereafter" may still cover you.
Assemble the contemporaneous record now. Site diaries, dated photos, the triggering instruction or RFI, and the programme impact against baseline. Strong records are what turn a late claim from hopeful to arguable.
Test the prejudice question. Be candid about whether your late notice actually deprived the Principal of a chance to mitigate. If it did not, say so, with evidence. If it did, your time argument is weaker — pivot harder to the payment route.
Run the payment claim in parallel. Submit a compliant payment claim for the value of the work under the Construction Contracts Act 2002, and diarise the response deadline. Your right to be paid for completed work is not hostage to the EOT dispute.
Get an independent assessment before you concede. A neutral read of the wording, the records and the prejudice often shows there is more life in a "late" claim than the first knock-back suggested.

This is general information, not legal advice — get advice on your specific contract.

FAQ — late extension-of-time claims in NZ

Q1: Is a late extension of time claim automatically time-barred under NZS 3910? No. The standard §10 wording requires notice within about 20 working days "or as soon as reasonably practicable thereafter", and says the certifier is "not bound to" grant an unnotified EOT — but that is a discretion, not an automatic bar. The certifier must still act reasonably and in good faith. A late claim is only truly dead where the Special Conditions have converted the deadline into a strict condition precedent.

Q2: What does "not bound to" actually mean for my late EOT claim? It means the certifier is permitted to decline a late claim, not required to. They retain a discretion, and under NZS 3910 that discretion must be exercised reasonably and in good faith. A refusal that simply cites lateness without engaging with prejudice or the merits can itself be challenged.

Q3: Can Special Conditions make my EOT deadline strict? Yes, and this is the real risk. Many Principals amend NZS 3910 so the EOT clause becomes a condition precedent — wording that the contractor "shall not be entitled" to an extension unless notice is given in time. Courts generally enforce clear condition-precedent wording, so under that drafting a late claim usually is lost. Always check the Special Conditions, not just the General Conditions.

Q4: If my EOT is refused for being late, can I still get paid for the variation work? Often yes. The Construction Contracts Act 2002 governs payment on a separate track from the contract's EOT time bar. If you submit a valid payment claim and no compliant payment schedule is issued in time, the full claimed amount can become payable, and adjudication gives you a fast route to enforce it. Losing the days does not automatically mean losing the payment.

Q5: How late is too late for an extension of time claim in NZ? There is no fixed cut-off under the standard wording — it turns on what was "reasonably practicable" in the circumstances and how much prejudice your delay caused. A short, explainable gap with strong contemporaneous records is recoverable far more often than a long, unexplained one backed by thin evidence. Where Special Conditions impose a strict deadline, though, "too late" means exactly the stated number of working days.

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Trueworks is built by Steve Parker — 20 years on the analytical side of NZ construction. Variation reviews, contract advisory, programme review, and AI-augmented document workflows. Trueworks is the productisation of that practice for builders: same defensible analysis, at a price and pace a NZ builder can actually use.

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steve@trueworks.co.nz · trueworks.co.nz