Concurrent delay in Australia

That framing is deliberate rather than a stylistic choice: it is the correct starting point because Australian courts have had comparatively little occasion to develop a general concurrency doctrine of their own. What first-instance authority does exist narrows the definition of concurrency sharply. Often disposing of a pleaded concurrency argument before any rule of entitlement is needed, and leaves the remedy for genuine concurrency to the contract. For the wider setting see extension of time in Australia.

The form-level split: apportionment against outright denial

Both forms are live on Australian projects today. AS 2124 remains widely used, especially in government work. AS 4000 is the current general form. The AS 2124 position is brutal for contractors, and it is the closest thing in the common-law world to a standard-form version of the England-and-Wales allocation-by-amendment approach. Except that in Australia it sits in the printed form, not a bespoke amendment layered on top of it.

AS 2124 cl 35.5 is also structurally different from AS 4000's clause in another respect: it splits into two limbs. Limb (a) covers delays before practical completion from any cause beyond the Contractor's reasonable control, expressly including industrial conditions and inclement weather. Limb (b) covers a narrower enumerated list. Principal-caused delay, quantity variations, latent conditions, directed variations, nominated- subcontractor issues, changes in law, and statutory-authority acts and delays. Applicable before, during or after completion. The concurrency denial in cl 35.5 bites only where one of the overlapping causes falls outside these qualifying categories.

Did apportionment survive into AS 4000:2025?

This is the single most important open question in Australian concurrent delay, and it should not be resolved by assumption. AS 4000:2025 superseded AS 4000-1997 in 2025, and Standards Australia's own framing is that "there has been no significant change to the allocation of risk". Which, because concurrency apportionment is squarely a risk-allocation question, implies the clause survived. But no source consulted for this corpus quotes the 2025 apportionment wording, confirms its retention, or even confirms its clause number, and the 2025 standard sits behind the Standards Australia paywall. Sources also disagree on whether the assessment and unilateral-power sub-clauses shifted numbering in 2025 at all.

The safe formulation, and the one this page uses throughout: the apportionment position is attributed to AS 4000-1997 cl 34.4, the edition where the wording is verified, and not to "AS 4000" unqualified or to the 2025 edition. Writing that "AS 4000:2025 cl 34.4 apportions concurrent delay" is not supportable on present sources. If the 2025 edition dropped or reworded apportionment, the Australian concurrency contrast described on this page would need rewriting for every new contract signed on the current form. Resolve this against the published standard before relying on it in a live matter.

The 84% problem: read the executed contract

The AS 2124 / AS 4000 divergence is the thing every Australian delay article leads with. It is also, on the numbers, describing a minority of real contracts.

Source: Melbourne Law School survey, 295 respondents.

So the famous divergence. Apportionment under AS 4000 against outright denial under AS 2124. Describes clauses absent from roughly three quarters of real Australian contracts. Read the executed contract, including its special conditions, before advising on either rule. The standard form tells you what was probably negotiated away, not what governs the project in front of you.

One recurring amendment is worth naming specifically because it attacks a different lever entirely: the duty that makes the Superintendent's unilateral power meaningful. Queensland TMR special conditions cl 2.2(j) provide that absolute discretions need not be exercised for the Contractor's benefit. A direct attack on the Peninsula Balmain / Probuild duty discussed below. The same device is reported to have succeeded in other matters and appears in amended AS forms generally. Where it is present, the reopening effect described in the next section may simply not exist on that project.

How Australian courts define concurrency

Where the contract's own wording does not resolve a dispute. Or where the parties are arguing about whether concurrency exists at all before reaching the contractual consequence. A thin body of first-instance authority supplies the definition, and it is narrow.

Australian Development Corporation Pty Ltd v White Constructions (ACT) Pty Ltd (1996) 12 BCL 317 at 345 (Giles CJ Comm D) holds that delays are not concurrent where the contractor-risk event starts first, causes actual delay, and ends after the qualifying event has finished. That is a causation-first move: it disposes of many pleaded concurrency cases without needing a rule of entitlement at all, because on those facts there was never a genuine overlap to begin with.

"Actual delay" carries its own gloss. In Turner Corporation Ltd v Coordinated Industries Pty Ltd (Rolfe J), the court held that potential delay is insufficient. Concurrency requires delay to the critical path, not merely to an activity that happened to be running alongside a qualifying cause.

On methodology, White Constructions Pty Ltd v PBS Holdings Pty Ltd [2019] NSWSC 1166 (Hammerschlag J) is the dominant modern authority. Both parties' delay experts were rejected. The court held that the choice of delay methodology must be driven by the factual evidence, and that the SCL Delay and Disruption Protocol is not a rule of law. Earlier, Alstom Ltd v Yokogawa Australia Pty Ltd (No 7) [2012] SASC 49 (Bleby J) rejected delay methodologies lacking widespread recognition in construction law, while Civil Mining & Construction Pty Ltd v Wiggins Island Coal Export Terminal Pty Ltd (Flanagan J) took the more permissive position that both prospective and retrospective methodologies were permitted. Read together, the direction of travel is toward the fact-led approach in White Constructions. Expect the Protocol to be cited, and expect it not to be decisive. No 2024–2026 Australian appellate authority on concurrent delay or delay analysis was located. The field is governed entirely by these first-instance decisions.

Why the Superintendent's power matters here

Australian standard forms give the Superintendent a unilateral power to extend time, exercisable even where the contractor has not claimed or is out of time, and that power must be exercised honestly and fairly (Peninsula Balmain Pty Ltd v Abigroup Contractors Pty Ltd [2002] NSWCA 211). Probuild Constructions (Aust) Pty Ltd v DDI Group Pty Ltd [2017] NSWCA 151 went further: to claim liquidated damages, the principal was obliged to exercise that power for delays it had itself caused.

The practical consequence for concurrency is specific to AS 2124. Where the form denies an EOT for the concurrent period under cl 35.5, a principal that caused part of the delay and then levies liquidated damages must still confront the Probuild obligation. The unilateral power partially reopens what cl 35.5 closes. A principal cannot simply point to the concurrency denial and walk away from delay it caused itself. That interaction is under-litigated and remains a genuine open question rather than a settled rule. It also underscores why a special condition like Queensland TMR's cl 2.2(j), which removes the duty to exercise discretions for the contractor's benefit, is such a consequential drafting move. See the prevention principle and time at large in Australia.

Under AS 4000, the same assessment machinery carries a deemed-approval consequence in the contractor's favour: where the Superintendent fails to assess an EOT claim within 28 days, the Contractor is deemed to have been granted the full extension claimed. Sources disagree on whether this sits within the same sub-clause as apportionment or in a separate one, so this page publishes the rule and not a sub-clause number. It is a powerful contractor remedy, and. Consistently with the 84% amendment picture above. It is frequently amended out or reversed into deemed rejection.

What Australian law on concurrent delay does not contain

The gaps are as load-bearing as the rules, and none of them should be smoothed over.

• There is no Australian judicial default rule on concurrent delay. Every Australian statement of "the" concurrency position is a statement about a contract clause, not about the common law.
• No 2024–2026 Australian appellate authority on concurrent delay or delay analysis was located. The field runs on four first-instance decisions. Australian Development Corp v White Constructions (1996), Turner v Coordinated Industries, Alstom v Yokogawa [2012] SASC 49, and Civil Mining & Construction v Wiggins Island. Plus White Constructions v PBS Holdings [2019] NSWSC 1166 on methodology.
• Whether AS 4000:2025 retained cl 34.4 apportionment is unresolved. Publish the apportionment position as AS 4000-1997's, not the current edition's, until the published 2025 standard has been checked.
• The exact sub-clause carrying the AS 4000 deemed-approval rule is disputed between sources. Publish the 28-day rule, not a sub-clause number.
• The interaction between the Superintendent's unilateral power and AS 2124 cl 35.5's concurrency denial has not been squarely litigated. What is recorded here. That Probuild partially reopens what cl 35.5 closes. Is a reasoned inference from the two lines of authority, not a holding on point.
• No Australian decision has adopted or rejected the SCL Delay and Disruption Protocol as a matter of law. It is cited, and it is not decisive. White Constructions (2019) is explicit on that point.

One consequence follows for anyone advising on an Australian delay claim: the citation list is short, contested at the edges, and thin above first instance. The record. The contract, its special conditions, and the critical-path evidence. Is doing more work in Australia than the case law is.

À propos de ce contenu Le contenu de la bibliothèque est une information générale sur la pratique des réclamations de construction, et non un avis juridique. Le droit à réclamation, les délais et la procédure sont régis par votre propre contrat et par le droit du lieu où les travaux sont exécutés. Révisé le 1 septembre 2026 · Signaler une correction