AS 4000 variation pricing: how to value a variation in Australia

Under AS 4000 (and, as summarised, AS 4902) a directed variation is priced by falling down a fixed order: prior agreement, then rates or prices in the Contract, then rates in a priced bill or schedule even though it is not a Contract document, and only then reasonable rates that carry profit and overheads. That ladder is the whole of the valuation machinery. It prices a variation that exists. It does not make one: the New South Wales Court of Appeal credited a developer with an approved, priced "variation" because the work had been in scope all along.

This is the valuation spoke of variations in Australia. The four-rung ladder across other forms is on the jurisdiction-neutral valuation page.

What this page could and could not read. Standards Australia text is paywalled, and no licensed copy of AS 4000:2025, AS 4000-1997, AS 4902-2000 or AS 2124-1992 was read. AS 4000-1997 cl 36 is quoted only from a public amended copy in a tender bundle, and says so; everything else on the forms comes from attributed firm summaries. Kaloriziko (which quotes that contract's amended AS 4902-based clauses), Peninsula Balmain, Mainteck and Chengcheng were read on AustLII.

AS 4000 cl 36.4: the pricing ladder, rung by rung

An amended AS 4000-1997 copy read for this page has the Superintendent price each Variation "as soon as possible" using an order of precedence. Two firm summaries set out the limbs in the same order: a CMGuide note (2011, on AS 4000) and Holding Redlich's design and construct series (November 2022, on AS 4902).

Record: limbs (a)–(c) as they appear in an amended AS 4000-1997 copy in a public tender bundle (whose limb (d) has been deleted by amendment), and the full order as summarised by CMGuide (AS 4000) and Holding Redlich (AS 4902). The "fight" column is opinion.

The one AS 4902-based text read, the amended contract in Kaloriziko, put a schedule of rates ahead of Contract rates and fixed the last limb's margin as percentages stated in the Annexure. Read the executed cl 36.4.

Limb (a) makes agreement paramount. That is why the proposed-variation procedure matters: it is the Superintendent's route to an agreed price before the work starts. An agreed price is the top rung, and everything below it is argument.

Limb (c) is the trap. It reaches rates the Contractor handed over at tender for evaluation, even where they never became Contract documents. (Opinion.) Assume anything priced and handed over is reachable, and price tender schedules as if they will be used against you.

Limb (d) is the only rung that expressly guarantees margin. So the Contractor's usual objective is to show that limbs (b) and (c) do not fit the varied work, and the Principal's is to show that they do. (Inference, from the structure of the limbs.)

What the sub-numbering rests on

The 1997 sub-numbering is confirmed from a public tender bundle containing an amended copy of AS 4000-1997: cl 36.1 Directing Variations, 36.2 Proposed Variations, 36.3 Variations for convenience of Contractor, 36.4 Pricing. The amended AS 4902-based contract in Kaloriziko has the same structure. Some published summaries put pricing at 36.2; for the 1997 edition that is wrong.

(Inference.) For AS 4000:2025, only cl 36.1 (Directing Variations) is confirmed; the rest is inferred and nothing reports a renumbering. Cite "AS 4000:2025 cl 36" and check the sub-number against your copy of the standard before you plead it.

On limb (d) the summaries differ: CMGuide gives the last limb as carrying profit but not overheads; Holding Redlich gives profit and overheads. Two copies resolve the shape, if not the words. An amended AS 4000-1997 copy ends cl 36.4 with "any deductions shall include a reasonable amount for profit but not overheads" (its limb (d) was deleted by amendment), and the Kaloriziko contract states one percentage for additions and another for deductions. (Inference.) The clause is an additions rule followed by a deductions rule; CMGuide has run the two together. Neither copy is the standard.

Negative variations: profit, overheads and a 10% rule nobody could find

Two rules about deleted work circulate for AS 4000. They should be treated very differently.

Profit but not overheads on deductions. The corpus records the pricing clause as continuing, after limb (d), with a rule that deductions carry a reasonable amount for profit but not overheads. On an omission the Principal recovers the Contractor's profit on the deleted work; the Contractor keeps the overhead recovery. The one AS 4000-1997 copy read (an amended tender copy) contains exactly that sentence; the unamended standard was not read.

"10% of the net omission." The research corpus describes a deduction of 10% of the difference where omissions exceed additions, and places it in cl 36.2. NEGATIVE FINDING Four searches on 26 September 2026 located no source for an AS 4000 or AS 2124 net-omission percentage, and none appears in cl 36 of the amended AS 4000-1997 copy read. In that copy cl 36.2 is the proposed-variation procedure, not a pricing rule, and the principal had added its own omissions clause (cl 36.5), which is where rules like this come from. (Opinion.) Do not plead, deduct or concede a 10% figure on the strength of the standard form. If your executed contract contains one, it is a special condition.

A comparison, clearly labelled: AIA A201–2017 §7.3.8 credits deleted work at net cost, so a US contractor keeps overhead and profit on it; CCDC 2 – 2020 reaches a similar result through its fee. If the AS 4000 deductions rule reads as reported, it runs the other way on profit. Nothing in this paragraph is authority for an Australian proposition.

The research corpus also reports that AS 4000:2025 cl 36.1 expressly allows work to be omitted whether or not others perform it. UNVERIFIED That goes to whether the omission is a valid variation at all, and is treated on the deemed variations spoke.

AS 4000 cl 36.2 and time-related costs: valuation or prolongation?

On AS 4000, when the Superintendent gives notice of a proposed variation, the Contractor answers with an estimate. Turtons (July 2018, on AS 4000-1997) summarises that estimate as covering the effect on the construction programme, the effect on the Date of Practical Completion, and the cost of the variation, in its words "including all time-related costs". Two independently amended copies agree in substance: the AS 4000-1997 tender copy asks for a quote for the cost "including all warranties and time-related costs, if any", and the AS 4902-based contract in Kaloriziko for a breakdown "including all warranties and delay costs, if any". The unamended wording, and the 2025 wording, were not read.

That matters because most forms keep time-related cost out of the variation price. JCT sends it to loss and expense, CCDC to its delay and claims clauses. NEC4 puts time and cost into one quotation. On the copies read, AS 4000's proposed-variation response sits with NEC4: the time-related consequence of a proposed variation is inside the price the Contractor is asked for. (Comparison; see the neutral valuation page.)

(The table is opinion, built on the summaries above.) The under-recovery trap is an inference from the drafting, not a holding. No Australian decision was located holding that an agreed AS 4000 variation price settles the delay costs of that variation. The one appellate decision found on the question runs the other way on a bespoke contract: Chengcheng (Aust) Enterprise Melbourne Pty Ltd v Mansfield Corporation Pty Ltd held that agreeing and paying a variation did not exclude a separate delay costs claim, even though that contract's variation valuation itself included time-related costs ([78]). That result turned on that contract's variation and delay costs clauses, which is the point. The answer is in the words of your contract, not in a general rule.

The double-recovery point is not only a lawyer's argument. The NSW Government's construction procurement guide on prolongation claims tells its assessors that variation payments usually already include a proportion for off-site overheads, and not to count them twice. Offer that reconciliation before it is asked for.

The template page gives wording for both halves: a proposed-variation response that names the time-related cost it includes, and a reservation for any delay cost it does not. See the variation notice and claim templates. Where the delay money travels separately, it is proved as in prolongation and delay costs in Australia.

No Hudson, Emden or Eichleay: delay overhead is proved as actual cost

Limb (d) promises a reasonable amount for overheads. It does not say how to prove it, and Australian law offers no formula to fall back on.

NEGATIVE FINDING No Australian decision adopting or rejecting the Hudson, Emden or Eichleay formulae was located: not in the corpus's survey, and not in two further searches run for this page on 26 September 2026. (Comparison.) On this site's research, England, Canada and the United States each have decisions engaging with the formulae; Australia has none located. (Opinion.) In a delay claim, treat off-site overhead as actual cost and actual under-recovery, proved from the accounts. A percentage lifted from a formula will be met with "where is that in your ledgers?". Within a variation price, limb (d) carries its own allowance for overheads; the argument there is what is reasonable.

The same discipline applies when a contractor gives up on itemising. Mainteck Services Pty Ltd v Stein Heurtey SA rejected the submission that proving a causal link between some breaches and the disruption entitled the claimant to the whole claim or an apportionment: "That is not the law" ([182]). "In a global claim, a significant cause of loss not attributable to the defendant is fatal" ([205]). A variation account that bundles unpriced variations with disruption and delay into one "total cost" figure takes that risk. See global claims and total cost in Australia.

AS 2124 cl 40.3 and cl 40.5: what changes on the older form

AS 2124-1992 remains in wide use. Its variations clause is cl 40, and on valuation the differences that matter are where margin goes, not the ladder itself.

Record: clause numbers and headings as summarised by Turtons (October 2018) and a state government AS 2124 special-conditions template relied on in the corpus. CONFLICT minor: one guide calls cl 40.3 a "detailed quotation", the template "Pricing the Variation"; they describe the same provision.

(Inference.) Because deemed variations and variations are priced down a ladder whose last rung carries margin, and cost-incurred adjustments are not, the two forms allocate margin in opposite directions on latent conditions and on change in law. Identify the form before advising on either. AS 2124 also carries a general prescribed-notice provision at cl 46.1. Its period is reported as 42 days in two independent sources, but sources disagree on what starts it UNVERIFIED: check your contract's cl 46.1 and special conditions. It is treated on the templates page and the written instruction spoke.

The Superintendent prices as well as directs

Under AS 4000 the same person directs the variation and then values it. When the Superintendent directs, it acts for the Principal. When it prices, it performs a certifying function between the parties.

Peninsula Balmain Pty Ltd v Abigroup Contractors Pty Ltd is the anchor. The contract (AS 2124-1992 cl 23) required the Superintendent to act "honestly and fairly". Hodgson JA held that the Superintendent is the owner's agent "only in a very loose sense", and that when certifying it "is not acting as the owner's agent, in the strict legal sense" ([50]); it must act "honestly and impartially", including in deciding whether to extend time without a claim ([79]). The case was about time, not valuation; that the same duty governs pricing is (Inference) from the certifying character of the task, and it is the reading the commentary adopts.

AS 4000:2025 did not resolve the tension. Carter Newell (August 2025) notes that AS 4000:2025 sets the Superintendent's general obligations at cl 20, but that the distinction between the Superintendent as the Principal's agent and as independent certifier or valuer "could be better reflected". (Opinion.) With cl 36.1 now reported to make the Superintendent the only gateway to an effective variation, and the Superintendent the valuer under the pricing clause, the duality matters more under the 2025 edition, not less. For a contractor challenging a valuation, a price shaped by the Principal's budget rather than by the ladder is the strongest structural argument available.

Kaloriziko (2025): approval is not a variation

This is the case that changes how a variation register should be read, and it is widely misreported.

Kaloriziko Pty Ltd as trustee for Ryde Combined Unit Trust v Calibre Construction Group Pty Ltd (No 2) was an appeal from Stevenson J ([2025] NSWSC 593). Adamson JA gave the principal judgment, and Mitchelmore and Kirk JJA agreed. The contract was a $31 million design and construct contract for apartments in Ryde, on general conditions in the AS 4902-2000 format, as amended. It was not AS 4000. Every clause number below is that contract's.

The rest of the reduction was $210,000 in liquidated damages (28 days at $7,500) and $2.9 million for the undervalue of properties transferred under a deed of settlement that released a party with co-ordinate liability. That is a contribution point, not a variations point. A statement that the builder's variations were cut by $3.24 million is wrong.

Items the developer approved, priced and paid

Five items (V1, V7, V11, V13 and V21, $569,778 paid) were held not to be variations: the work was within the scope. The developer's approval and payment did not displace cl 37.2, under which, as the Court quotes it, "[p]ayment other than final payment shall be payment on account only". The trial judge had held otherwise, and erred. But each item was an "excluded item" under the Formal Instrument of Agreement: work to be done but paid for separately. So the builder kept the money and owed no credit.

The item the developer approved but never paid

V44, consultancy fees, was approved but not paid. The fees were within the scope and not excluded, and pre-contract discussions were irrelevant because of an entire contract clause. The Court held that the approval did not operate as a direction under cl 36.1, and could not price a variation under cl 36.4. In the Court's words:

The pricing of a non-variation does not convert it to a variation.

The judgment's headnote records the approval as no more than an implied admission, capable of being displaced by the true contractual position. The developer was credited $133,175. And the Court put the pricing machinery in its place: "When cl 36 is complied with (that is, that there is a variation which is priced), the builder has a right to payment in addition to the original contract sum". The ladder presupposes the variation.

The Court also held that the date for practical completion had not been validly varied, because no written instrument executed by both parties existed, as cl 5(b) of the Formal Instrument required, and neither an oral agreement nor conduct was proved. That is a finding on the evidence, not a holding that a written-variation clause excludes oral variation in Australia. The written-direction question is on the written instruction spoke.

What it means for a contractor's variation register

(Opinion.) For a principal the case cuts both ways. Approval did not bind this developer, but it was still an admission it had to displace, and it displaced it because an entire contract clause shut out the pre-contract history. An approval given casually, for cash-flow or relationship reasons, is evidence against you at final account.

The drafting responses

(Opinion, offered as drafting practice rather than authority.)

• Contractors: provide that a variation price agreed or determined under the pricing clause is final and binding once issued, and carve variation valuations out of the on-account language in the payment clause. And ask that every approval name the written direction it rests on.
• Principals: provide expressly that approving or paying a price is not an admission that the work is a variation, keep the on-account language, and keep an entire agreement clause that does real work.
• Both: a register line should carry the scope reference, the direction reference, the pricing limb used and whether time-related cost is in the price. Those four fields are what Kaloriziko tested.

Where Storia fits

Every rung of the ladder rests on records: the rate that applies, the quantities, the time-related cost in the price, and above all the trail showing the work was outside the scope before anyone priced it. Kaloriziko is what happens when the approval survives and that trail does not. Storia turns drawings, RFIs, schedules, correspondence and field reports into one source-linked project record, so each line of a variation register traces back to the scope document, the written direction and the pricing basis it came from. Because the record is built as the work happens, the valuation can be agreed in coordination, or taken from records to a claim-ready case in days.

The strongest case against this page's framing

A careful opponent would say that Kaloriziko is a narrow decision on an amended AS 4902-based contract with an entire contract clause and an express on-account payment clause, and that the page makes too much of it. That is partly right. The holding is tied to those clauses, and a standard AS 4000 contract has to be read on its own words. But the sentence Kaloriziko turned on, "Payment other than Final Payment shall be payment on account only", appears in cl 37.2 of both amended copies read, AS 4000-1997 and AS 4902-2000-based, so it is very likely the 1997 standard's own text. The 2025 wording was not read. And the core reasoning is not clause-specific. A pricing mechanism that prices "a variation" assumes one. An approval is evidence, not a contract. Neither point depends on AS 4902.

The same opponent would say the time-related-cost trap is overstated. It rests on amended copies and a firm summary, not the licensed clause, no Australian case applies it, and the one appellate decision found (on a bespoke contract) let a delay costs claim run alongside an agreed variation. Also fair. (Opinion.) The answer is that the cost of the discipline is one sentence on an estimate, and the cost of being wrong is the delay money on every priced variation. Where the law is unsettled, write down what the price includes.

The ladder's order is consistent across every source read. The 1997 decimal is confirmed; the 2025 decimal is reported.

What to do about it

(Opinion, offered as working practice rather than as authority.)

1. Find the rung before you argue the price. Is there a prior agreement? A rate in the Contract? A tender schedule that reaches? Only then argue what is reasonable.
2. Price tender schedules as if they will be used. Limb (c) reaches them even if they never became Contract documents.
3. Answer every proposed-variation notice with a stated scope of price: direct cost, time-related cost, and what is reserved. Use the template.
4. Reconcile before you are asked. Show that the preliminaries and overhead in the variation account are not in the delay claim.
5. Prove delay overhead from the accounts. No formula located will carry it in Australia.
6. Do not concede, deduct or claim a 10% net-omission figure unless it is in your executed contract.
7. Keep the scope trail on every register line. Approval is not a variation, and payment on account is not settlement.
8. Read the executed contract. Pricing clauses are commonly amended; the Kaloriziko contract's limbs differed from the standard. The form tells you what was probably negotiated away, not what governs.

In Victoria, the limits on adjudicating disputed variations (ss 10A–10B of the security of payment Act) were repealed from 15 April 2026, subject to the transitional s 54; see adjudicating the variation account in Victoria. For the whole Australian picture, return to variations in Australia.

About this material Library content is general information about construction claim practice, not legal advice. Entitlement, deadlines and procedure are governed by your own contract and by the law of the place the work is performed. Reviewed September 26, 2026 · Report a correction