AS 4000 and Australian Standard Construction Contracts

The standard form you use decides who wears a latent condition, who pays for a delay nobody planned for, and how quickly your builder can convert an instruction into a variation claim. Those are the three things most likely to move your margin between land settlement and practical completion. Amendments to these forms are near-universal, so the published document is a starting position rather than a finished one, and the marked-up copy that comes back with the tender is where the allocation actually gets settled. Questions worth putting to your construction lawyer on that mark-up are set out near the end.

Figures, thresholds and commencement dates in this guide were current at the date of writing and change regularly, particularly the security of payment rules, which several states amended over the past two years. Each linked primary source is where to confirm the current position.

What is AS 4000 and why does it matter to a developer?

AS 4000 is the most widely used general conditions of contract for construct-only building work in Australia, published by Standards Australia. It is a set of general conditions that sits behind your drawings, specification and annexures, and it decides how risk, time and money move between you as principal and the builder as contractor.

Standards Australia describes AS 4000 as “a foundational document for construction contracts in Australia” that “sets out the rights, responsibilities, and obligations of parties involved in a project”. That neutral description understates why it matters commercially. The general conditions are where your contingency either holds or gets eaten. A form that makes latent site conditions the principal’s risk, or that gives the contractor a generous entitlement to delay costs, generally translates into a lower tender price and a wider distribution of outcomes. A form that pushes those risks onto the builder tends to produce a higher price and a narrower distribution. Neither is free.

The practical framing for a developer is this. Your feasibility carries a build cost, a construction programme and a contingency. The contract form determines how many of the ways that build cost can move are your problem rather than the builder’s. Read the conditions with that question in front of you and the document stops being legal furniture.

What changed in AS 4000:2025?

Standards Australia published a revised AS 4000:2025 on 30 June 2025, its first substantial revision in almost three decades. Standards Australia states the update reflects “legislative and industry changes over the past 28 years”.

The changes Standards Australia identifies are:

• Legislative alignment. New provisions dealing with Goods and Services Tax (GST), including tax invoices and payments; clauses managing security interests under the Personal Property Securities Act; and updates for appointing a principal contractor under work health and safety legislation.
• Modernised language and structure. Simplified drafting, with all defined terms consolidated into Clause 1 rather than scattered through the document.
• Clarified practical completion. Standards Australia states the updated definitions include that the completion date may precede the certificate issuance.
• Flexible dispute resolution. New options including expert determination, mediation and dispute boards, with the default process being negotiation followed by arbitration or litigation.
• A Formal Instrument of Agreement. An optional short-form agreement is now included, so parties no longer need to source or draft one separately.

How those forms map onto each delivery model is covered in the guide to construction delivery models. What did not change is the risk balance. Standards Australia states the risk allocation “remains consistent with the 1997 edition, based on the Abrahamson Principles”, quoting technical committee member John Cooper describing those principles as “widely accepted in the construction industry as ground rules for a fair and equitable allocation of risks in construction contracts”. The Abrahamson approach, put plainly, allocates each risk to the party best placed to control it, insure it, or absorb it at least cost.

For a developer this creates a specific trap. If your project team has been marking up AS 4000-1997 for years, that mark-up may reference clause numbers that have moved. Standards Australia’s own advice, via John Cooper, is to pay “close attention to every detail in the document” and take “particular care when making any changes or amendments to maintain consistency, clarity and certainty”. Cross-references that no longer point where they used to are a common source of dispute, and they tend to surface at the worst moment, which is when a claim is already on foot.

Standards Australia has also flagged that related documents will be revised to align with the 2025 edition, including HB 140:2000 Administration Manual for AS 4000 and AS 4902-2000 General Conditions of Contract for Design and Construct. At the time of writing, AS 4902 remains in its 2000 edition. That mismatch matters: a design and construct project may be running on a 2000-edition document while a construct-only project down the road runs on the 2025 edition, and the two no longer share identical drafting.

What happened to AS 11000?

Developers who encountered the AS 11000 proposal may reasonably ask whether it superseded AS 4000. It did not. Standards Australia’s January 2015 statement proposed merging AS 2124-1992 and AS 4000-1997 into a new AS 11000 suite, with a companion AS 11001 on dispute resolution, and opened a public comment period ending 27 March 2015. The AS 4000:2025 revision, rather than an AS 11000 publication, is what industry ended up with. If a consultant refers to AS 11000, that is worth clarifying before it reaches a tender document.

Which Australian standard form contracts do developers actually encounter?

The standard forms a developer meets fall into three groups: the Standards Australia family, government forms, and industry-published forms. Which one lands on your desk generally depends on who is procuring, how big the job is, and who carries the design.

Standards Australia lists AS 4902-2000 as General conditions of contract for design and construct, part of the suite based on AS 4000-1997. AS 2124-1992 and AS 4305-1996 remain available through the Standards Australia catalogue.

The forms are copyright documents. Using one means licensing it, and Standards Australia now makes AS 4000:2025 available in an editable Microsoft Word format under licence. Budget for the licence and for the legal time to mark it up, because those are real project costs that a feasibility often forgets. They tend to be small relative to the risk they manage.

How does AS 4902 differ from AS 4000, and when does that matter?

AS 4902 is the design and construct equivalent of AS 4000, and the difference that matters commercially is who owns the design risk. Under a construct-only form the principal supplies the design and carries the consequences if it is wrong or incomplete. Under a design and construct form the contractor takes responsibility for design, usually against a principal’s project requirements document that you prepare.

Standards Australia describes AS 4902-2000 as suitable for design and construct, design development and construct, and design novate and construct procurement methods. Those three are meaningfully different in practice:

• Design and construct. The contractor designs from your brief. You give away control of detail in exchange for a single point of responsibility.
• Design development and construct. You take the design to a partial stage, often development approval or early design development, and the contractor completes it. The gap between where you stopped and where they started is where most disputes live.
• Design novate and construct. You engage the consultants, take the design to a defined stage, then novate the consultant agreements to the contractor. The contractor inherits the design and, from novation onwards, responsibility for it.

The developer’s exposure under any of these is the principal’s project requirements document. If it is vague, the contractor may deliver the cheapest thing that arguably complies, and your product quality drops without a contractual remedy. If it is over-specified, you have effectively designed the building yourself and may have undermined the single-point responsibility you were paying for. Most developers find the drafting of that document is where the money is either protected or lost, and it is a task for the design team and the lawyer together rather than either alone.

Our guide to design and construct contracts covers the delivery model in more depth, and the guide to guaranteed maximum price contracts covers the pricing overlay that is often bolted onto a design and construct form.

What is GC21 and when will a developer encounter it?

GC21 is the NSW Government’s standard form construction contract, and a private developer meets it when working with or for a NSW agency, or on land where an agency is a party. buy.nsw states that GC21 Edition 2 is recommended for construction contracts valued at more than $2 million, and that agencies should use it for complex and high-risk contracts valued over $1 million where circumstances warrant.

Three features distinguish GC21 from the Standards Australia family, and each has a commercial consequence.

It is relationship-based rather than adversarial in design. buy.nsw describes the framework as “relationship-based contracting with specified requirements for cooperation between the contracting parties”, aimed at “a transparent and balanced allocation of risk” and “the mitigation of disputes”. In practice that means mandated start-up workshops, regular meetings, and an escalation path before anything becomes a formal dispute. That machinery costs management time. It also tends to catch problems earlier.

It uses an authorised person rather than a superintendent. Each party nominates an authorised person, and a senior executive for disputes. buy.nsw publishes a separate resource on the role of an authorised person. This differs from the superintendent model in the Standards Australia forms, where a single person certifies and also, in many arrangements, acts as the principal’s agent.

It is free and heavily supported. The full GC21 suite, including general conditions, conditions of tendering, tender schedules, preliminaries, a clause commentary and more than 100 pro-forma letters, is downloadable at no cost from buy.nsw. That support material is genuinely useful reading even if you are not contracting with a NSW agency, because it shows how a sophisticated principal thinks about the same clauses you are negotiating.

GC21 is also live rather than static. buy.nsw publishes an amendment log, and the recent entries show how quickly the drafting moves. The 1 December 2025 amendments alone changed the notification period for adverse site conditions, restricted a contractor’s entitlement to additional costs from a site condition to “unavoidable additional costs”, added notes confirming that a contractor commits a breach if it fails to notify a possible variation or delay within the specified time, and extended the time for referring an issue to expert determination from 28 to 42 days. A 23 February 2026 amendment then reverted the adverse site condition notification period from three business days back to seven days. If your team is working from a GC21 copy downloaded a year ago, it is not the current form.

Variants of GC21 have been adopted beyond NSW. Infrastructure Canberra publishes a GC21 document suite for Australian Capital Territory projects, and the South Australian Department for Infrastructure and Transport publishes its own GC21 terms and conditions for civil construction. Those are modified forms rather than copies, so the NSW clause commentary will not always match.

Which government forms apply in each state and territory?

Government forms vary by jurisdiction, and the variation matters if you are delivering social or affordable housing, working on a government-owned site, or bidding into a public works programme.

New South Wales uses GC21 Edition 2, as above, published through buy.nsw.

Victoria requires contracts to be in a form approved by the Secretary to the Department of Treasury and Finance under Construction Direction and Instruction 7.1, and those approved forms are collectively called the Victorian Public Construction Contracts. The published suite is tiered by value: the Minor Works Contract (Short Form) is stated as suitable for simple works projects up to $200,000 excluding GST; the Medium Works Contract (Short Form) for procurements between $200,000 and $5 million excluding GST; and the Medium Works Contract for procurements between $1 million and $20 million excluding GST. Victoria notes that all three can be used for both construct-only and design and construct projects. Separately, some Victorian agencies still use modified Standards Australia forms: the Victorian Schools Building Authority’s approved contracts include a modified AS 2124-1992 for construct-only works over $15 million and a modified AS 4300-1995 for design and construct works over $15 million.

Queensland publishes the Transport Infrastructure Contract suite through the Department of Transport and Main Roads, covering construct-only, design and construct, and sole invitation variants, plus a Minor Infrastructure Contract suite for smaller works. These are infrastructure rather than building forms, and a developer typically encounters them on works-authorisation or road-dedication packages associated with a subdivision.

The Australian Capital Territory uses the GC21-based Infrastructure Contract Suite noted above.

South Australia uses a state variant of GC21 for civil construction through the Department for Infrastructure and Transport.

Western Australia, Tasmania and the Northern Territory each publish their own government contracting requirements. The position in those jurisdictions is broadly similar in structure, being a state-approved form or a modified Standards Australia form depending on value and works type, but confirm the current requirement with the relevant procurement agency before pricing a public works package, because the approved form list changes.

For privately funded development, none of these government forms is mandatory. They are worth knowing about because agencies bring their own paper, and because a well-maintained public form is a useful benchmark against which to read the mark-up a builder hands back to you.

What are ABIC contracts and where do they fit?

ABIC, the Australian Building Industry Contracts, is a suite of standard-form building contracts published jointly by the Australian Institute of Architects and Master Builders Australia, and it is designed specifically for architect-administered projects. The suite includes major works, simple works and basic works versions, scaled to project complexity, and it has moved to a digital contract platform.

The distinguishing feature is the administration model. ABIC assumes the architect administers the contract, issuing instructions, assessing progress claims and certifying completion. That suits a developer who is already running an architect-led delivery model and wants the person who understands the design intent to be the person policing it on site. It suits less well where the developer wants an independent superintendent, or where a builder’s contract administration team expects the Standards Australia machinery it uses on every other job.

A practical consideration developers raise is lender familiarity. Development finance is typically documented against a contract the financier’s quantity surveyor recognises, and a form the funder has not seen before can add time to the approval path. That is a question for your broker and financier rather than something to assume either way, and it is worth asking early rather than after the contract is executed. Our guide on choosing a builder covers the tender and selection process that sits upstream of this decision.

Which form suits which delivery model?

The relevant comparison is between the delivery models, not between the documents. The document tends to follow the model.

Construct-only delivery means you take the design to a full documentation set and tender it. You keep control of the product, you carry the design risk, and you generally get sharper pricing because the builder is pricing a known scope. AS 4000:2025 is the mainstream Standards Australia form for this. GC21 accommodates it as what buy.nsw calls “developed design (construct only)”. The commercial trade-off is that every documentation gap becomes a variation, and documentation gaps are common when a developer compresses the design programme to hit a settlement date.

Design and construct delivery means the contractor carries design. AS 4902-2000 is the Standards Australia form, and GC21 accommodates full design and construct as well. You trade product control for single-point responsibility and, often, an earlier start on site. The trade-off is that your principal’s project requirements document has to do the work your drawings would otherwise have done.

Minor works covers small, simple, short-duration packages. AS 4305-1996 is the Standards Australia minor works form, and Victoria’s Minor Works Contract (Short Form) covers the same territory for public projects. Using a full head-contract form on a $150,000 package generally costs more in administration than the risk it manages.

Architect-administered delivery points toward the ABIC suite, for the reasons above.

There is no single right answer, and the honest position is that the form is a downstream consequence of decisions you have already made about design control, programme and price certainty. If those decisions are still open, that is the conversation to have with the lawyer and the quantity surveyor together, not a document selection exercise.

Where does the standard form actually hit your feasibility?

Six mechanisms in a standard form contract do most of the work on your bottom line. These are the clauses to read first, in whichever form you end up with.

Latent conditions. Site conditions that could not reasonably have been anticipated. Whether the principal or the contractor carries them, and how the entitlement is triggered, drives the size of the contingency you need. GC21’s recent amendments show how fine the drafting gets here: the notification period for adverse site conditions moved from seven days to three business days in December 2025 and back to seven days in February 2026, and the entitlement was narrowed to “unavoidable additional costs”. A day either way on a notification clock can decide whether a claim survives. Our guide to construction contingency covers how to size the allowance this creates.

Variations. How an instruction becomes a priced change, who values it, and what happens if the parties do not agree. GC21’s December 2025 amendments added a note confirming that a contractor commits a breach of contract if it fails to notify the principal of a possible variation within the specified time period. Read the equivalent provision in your form and understand which side the silence favours.

Extensions of time and delay costs. These are two separate questions and developers routinely conflate them. An extension of time protects the contractor from liquidated damages. Delay costs are a separate entitlement to be paid for the time. A form can grant the first without the second. Which combination applies decides whether a six-week weather delay costs you your liquidated damages entitlement, your holding costs, or both. The construction programming guide covers how the programme interacts with these entitlements.

Liquidated damages. A pre-agreed daily or weekly rate for late completion. The rate needs to be a genuine estimate of your loss, and setting it too high risks it being unenforceable, which leaves you proving actual loss. Setting it too low caps your recovery below your real holding costs. This is a calculation question for you and the lawyer, and the inputs are your finance costs, your rates and land tax, and your sales or leasing programme. The land holding costs guide covers the inputs.

Provisional sums and prime cost items. Amounts included in the contract sum for work not yet fully defined. Every provisional sum is a number in your feasibility that has not been competitively priced. Two or three are normal. A dozen means you have effectively tendered an estimate.

Security and retention. Bank guarantees or retention held against defects and performance. This affects cashflow on both sides, and the release mechanism decides when your money comes back. As set out below, Victoria has recently changed the rules on calling on performance security, and that change applies to contracts already on foot.

Each of these belongs in your development cashflow model as an assumption you can flex, rather than as a single deterministic number. The point of reading the contract with a feasibility open is to work out which assumptions the document lets someone else move.

What do amendments and special conditions do to the risk balance?

Almost nobody signs an unamended standard form. Builders mark up, principals mark up, and the executed contract is typically the general conditions plus a schedule of special conditions that can run to dozens of pages. Three things follow from that.

The balance the publisher describes is not the balance you signed. Standards Australia describes AS 4000:2025 risk allocation as based on the Abrahamson Principles. That description applies to the unamended form. If your special conditions shift latent conditions, delay costs and design responsibility onto the builder, you have a different document, and the price will generally reflect it.

Amendments create internal inconsistency. Standards Australia’s own guidance on the 2025 revision is to take “particular care when making any changes or amendments to maintain consistency, clarity and certainty”. A clause deleted in one place and cross-referenced in three others is how a contract becomes ambiguous, and ambiguity in a contract you drafted tends not to be resolved in your favour.

Heavy amendment can attract the unfair contract terms regime. Changes to the unfair contract terms law took effect on 9 November 2023. The Australian Competition and Consumer Commission (ACCC) states that from that date, “proposing, using or relying on unfair contract terms in standard form contracts will be banned and penalties for breaches of the law will apply”. The small business threshold changed too: for new or varied standard form contracts from that date, the protections apply where the other business has “fewer than 100 employees” or makes “less than $10 million in annual turnover”.

That threshold captures a great many builders, subcontractors and consultants a developer contracts with. The Australian Competition and Consumer Commission (ACCC) also notes there is a presumption that a contract is a standard form contract, and that “the party that prepared the contract must prove that it isn’t”. The regime lists terms that may be unfair, including terms that allow one party but not the other to avoid or limit their responsibilities, to end the contract, or to change its terms. A one-sided special conditions schedule handed to a small builder on a take-it-or-leave-it basis is precisely the fact pattern the regime addresses. If a court finds a term unfair it is void, and the rest of the contract continues without it, which may leave you without the protection you thought you had bought. This is a question to put to the lawyer in terms of your specific mark-up, not a reason to abandon amendments.

What does security of payment legislation override?

Every state and territory has security of payment legislation, and it overrides contract terms. Whatever your standard form says about payment, the statute in the relevant jurisdiction sets a floor the contract cannot go below. Two consequences matter to a developer.

Pay when paid clauses have no effect. A provision making your payment obligation contingent on you being paid by someone else is void under security of payment legislation across Australian jurisdictions. In Western Australia, for example, the Small Business Development Corporation states that any pay-when-paid clauses in contracts made after 1 August 2022 have no effect under the Building and Construction Industry (Security of Payment) Act 2021 (WA).

Victoria’s changes apply to contracts already signed. This is the significant recent development and it is not yet reflected in most published commentary on the standard forms. The Building and Plumbing Commission states that the Building and Construction Industry Security of Payment Act 2002 (Vic) has been amended by the Building Legislation Amendment (Fairer Payments on Jobsites and Other Matters) Act 2025, that the amendments take effect from 15 April 2026, and that the changes “will impact all construction contracts, including contracts entered into before the amendments came into operation on 15 April 2026”.

The Building and Plumbing Commission sets out several changes that directly cut across standard form drafting:

• Maximum payment and security release terms. A contract provision has no effect to the extent it provides for payment of a progress payment, or release of a performance security, later than 20 business days after a payment claim or performance security claim is served in accordance with the Act. Parties “will not be able to agree any longer period, and to the extent that they do, those terms will have no effect”.
• Wider pay when paid restriction. The definition now captures provisions making the liability to pay, the due date for payment, a right to claim money owing, or a right to claim release of a performance security contingent on the operation of another contract.
• Unfair notice-based time bars. A notice-based time bar may be determined unfair by an adjudicator, court, arbitrator or appointed expert if compliance “is not reasonably possible” or “would be unreasonably onerous”. If found unfair, the provision has no effect on the entitlement in that proceeding, though it continues to have effect in other circumstances under the contract.
• When a payment claim can be served. A contract cannot require a payment claim to be served later than the last day of each named month in which the work was carried out, and cannot require milestone payment claims to be served less frequently than monthly. The Building and Plumbing Commission notes one exception, for work carried out between 22 December and 31 December, where the contract can set 31 January in the following year.
• Notice before calling on performance security. A party cannot have recourse to a performance security unless it has served a written notice of intention and at least five business days have passed, or a longer period if the contract provides one. The Commission states that this requirement “will form part of every construction contract”.

For a Victorian developer, that last point in particular is a change in behaviour rather than paperwork. If your process was to call on the bank guarantee and argue afterwards, that is no longer available. It also has a cashflow consequence in the other direction: a special condition that gave you 30 or 45 days to pay progress claims may no longer operate, which pulls your drawdowns forward and changes the shape of your funding curve.

New South Wales, Queensland, South Australia, Tasmania, the Australian Capital Territory and the Northern Territory each have their own security of payment statute with its own timing, claim and adjudication rules. The NSW Government publishes security of payment guidance for construction contractors, and the Queensland Building and Construction Commission publishes guidance under the Queensland regime. The rules are not uniform, and a developer building in more than one state should assume the payment machinery differs even where the head contract form is identical.

When does a standard form not comply with residential building law?

If your works are domestic or residential building work, consumer protection legislation in your state may impose contract requirements that a commercial standard form does not meet. This catches developers more often than it should, typically on townhouse, villa and small apartment projects, and on any structure where the end contract runs to an individual purchaser rather than a corporate entity.

New South Wales. The Home Building Act 1989 (NSW) sets contract requirements for residential building work. NSW Government guidance indicates a written contract is required for work over $5,000, and that a more extensive large-job contract applies for work over $20,000, with requirements including insurance details, progress payments, warranties and a cooling-off period. The Home Building Compensation Fund is compulsory for jobs of $20,000 or more. The NSW guide to providing home building contracts sets out the current obligations, and our home warranty insurance guide covers the insurance requirement in more depth.

Victoria. Consumer Affairs Victoria states that for work worth $10,000 or more you must have a written contract with a registered builder, known as a major domestic building contract, and that a builder must not enter one unless registered as a building practitioner under the Building Act 1993 (Vic). It also states that for work worth $16,000 or more, do not proceed until the builder has provided a current certificate of domestic building insurance covering the address. Consumer Affairs Victoria publishes guidance on what work requires a building contract.

Queensland. The Queensland Building and Construction Commission Act 1991 (Qld) creates two tiers of regulated domestic building contract. The Queensland Building and Construction Commission states that contracts with a price between $3,300 and $20,000 are level 1 regulated contracts and those of $20,000 or above are level 2 regulated contracts, with level 2 carrying additional requirements including provision of the approved consumer building guide before the owner signs. The Commission publishes guidance on domestic building contracts.

Other jurisdictions have their own residential building contract regimes with their own thresholds and mandatory terms. The pattern is consistent even where the detail is not: once work is characterised as domestic or residential building work, a commercial general conditions document is unlikely to satisfy the statutory requirements on its own.

The developer’s trap is characterisation. Whether your project is domestic building work is a legal question that turns on the nature of the building and the identity of the parties, not on how you describe the project in your feasibility. Get it wrong and you may have an unenforceable contract, a compliance breach, or an insurance gap that surfaces at the worst possible moment, which is usually when a purchaser rescinds or a defect claim arrives.

What applies in New Zealand?

New Zealand’s principal standard form is NZS 3910, Conditions of contract for building and civil engineering construction, published by Standards New Zealand. The 2023 edition was published in November 2023 and represents the most substantial revision of the form in decades.

The change most relevant to a developer is structural. The 2023 edition separates what was a single engineer role into two: a contract administrator, who acts for and on behalf of the principal and issues instructions including on variations, and an independent certifier, who acts impartially on decisions entrusted to that role, such as practical completion. The previous arrangement, where one person both acted for the principal and made impartial determinations, had long been a source of tension. Splitting the roles removes that tension but adds a second appointment, and a New Zealand developer needs to budget for both and decide who fills each.

NZS 3910:2023 is drafted to sit alongside the Construction Contracts Act 2002 (NZ), which is New Zealand’s equivalent of the Australian security of payment statutes and which similarly overrides inconsistent contract terms. An Australian developer working across the Tasman should not assume the Australian forms translate: NZS 3910 has its own definitions, its own timing, and its own relationship with New Zealand statute.

What to ask your construction lawyer

Take these to the lawyer before the tender documents go out, not after the builder returns a mark-up.

• Which form suits the delivery model we have already chosen, and what does that choice cost us in price, programme and product control?
• Is this project domestic or residential building work in this state, and if so what does the relevant Act require that a commercial general conditions document does not provide?
• Under this form as amended, who carries latent conditions, and what has to happen, by when, for the contractor to have an entitlement?
• Does an extension of time under this form also carry an entitlement to delay costs, and if so how are those costs calculated and capped?
• Is our proposed liquidated damages rate defensible as a genuine pre-estimate of our loss, given our finance costs and our sales or leasing programme, and what is the exposure if it is struck down?
• Are we the party who prepared this contract for the purposes of the unfair contract terms regime, and does the builder or any consultant fall under the fewer-than-100-employees or under-$10-million-turnover threshold?
• Which of our special conditions would you expect a court or adjudicator to look hard at under that regime, and what would we lose if any of them were void?
• If the project is in Victoria, which of our payment, security release and notice provisions no longer operate under the amendments that took effect on 15 April 2026, and what do we need to change in our administration to comply?
• What is the security of payment position in each jurisdiction where we are building, and where does the statute override what we have drafted?
• If we are using AS 4000, are we on the 2025 edition or the 1997 edition, and does our standard mark-up still reference the right clause numbers?
• Under a design and construct form, what would you strengthen in our principal’s project requirements document to protect the product quality we have assumed in the feasibility?
• Who is the superintendent or authorised person, what are their dual roles under this form, and what is our exposure if they get a certification wrong?

What to ask your quantity surveyor

• How much of the tendered price is attributable to the risk allocation in this form, and what would the price look like under the alternative form we are considering?
• Which provisional sums and prime cost items sit in this contract sum, and what is the realistic range on each?
• Given the payment terms in this contract, and any statutory limits on those terms, what does the drawdown profile look like month by month?
• What contingency does this risk allocation justify, and how does that change if we shift latent conditions to the contractor?
• Are the liquidated damages inputs we have given the lawyer consistent with the holding costs in the feasibility?

What to ask your financier’s representative

• Is this contract form one your quantity surveyor is familiar with, and does it affect the timing or conditions of approval?
• Does the security and retention structure in this contract sit comfortably with the facility, particularly the release mechanism?
• If the payment terms are shortened by statute, does the drawdown schedule in the facility still work?

The practical summary

AS 4000:2025 is the mainstream construct-only form and was revised on 30 June 2025 for the first time in 28 years, with the same underlying risk balance but modernised drafting, consolidated definitions, clarified practical completion and expanded dispute resolution options. AS 4902 remains its 2000-edition design and construct counterpart, pending alignment. GC21 is the NSW Government form and is amended frequently enough that a year-old copy is out of date. ABIC suits architect-administered projects. Government forms differ by state.

What matters commercially is not which document you pick but which of the six mechanisms above are open to being moved against you: latent conditions, variations, extensions of time and delay costs, liquidated damages, provisional sums, and security. Read the form with your feasibility open, note which assumptions somebody else controls, and take that list to the lawyer.

And whatever the contract says about payment, check the security of payment statute in your jurisdiction, because in Victoria at least, the statute now overrides terms in contracts that were signed long before the rules changed.