Australian Standard Contracts
AS 4000 Construction Contract Advice
AS 4000-1997 is the most widely used construct-only head contract in Australia. Advice, review, special conditions and disputes, from a solicitor who is also a registered architect.
AS 4000-1997, formally the General Conditions of Contract, is one of the most widely used head contracts for construction work in Australia. It is a construct-only contract: the principal supplies the design and the contractor builds to it. It is the flagship of the modern AS 4000 suite and the practical successor to AS 2124-1992.
The contract is administered by a Superintendent, who assesses and certifies progress claims, decides variations and extensions of time, and manages the path to practical completion. A defining feature of AS 4000 is that the Superintendent is required to act reasonably and in good faith, a broader duty than the honest and fair standard in the earlier suite.
AS 4000 now exists in two editions. AS 4000-1997 is the long-standing version that most contracts still refer to, and Standards Australia has since published a modernised edition, AS 4000:2025. In practice either edition is rarely signed in its standard form: special conditions adjust the balance of risk to the project, and those amendments are where most of the real negotiation happens. Getting them right, and knowing which edition and amendments apply, is where advice matters most.
Where Christopher can help with AS 4000
Whether you are a principal issuing an AS 4000 contract or a contractor being asked to sign one, Christopher helps you understand what you are agreeing to and negotiate the terms that carry the most risk. Here is where he can assist.
Special conditions
Drafting and reviewing the special conditions that adapt AS 4000 to your project, so the amendments achieve what you intend without quietly undoing the balance of the standard form.
Contract review before signing
A review of the contract and its annexures and special conditions before you commit, identifying where risk really sits for the party you act for, and confirming which edition applies.
Administration and certification
Advice on the Superintendent role, progress claim assessment, variations and extensions of time, informed by having performed contract administration directly.
Payment and delay disputes
Strategic advice when a certification, a claim or a delay becomes contentious, including how the contract interacts with security of payment legislation.
Key features of AS 4000
Construct only
The principal is responsible for the design through its own consultants; the contractor is responsible for building it. Design risk sits largely with the principal unless special conditions move it.
Superintendent administration
A Superintendent administers the contract, certifying payments and deciding claims, and must act reasonably and in good faith when performing its certifying functions.
Progress payments and certification
Payment is by progress claim, assessed and certified by the Superintendent within set time frames, and interacts with security of payment legislation in the relevant state.
Time, extensions and delay costs
Extensions of time run on strict notice requirements, and acts or omissions of the principal, the Superintendent or another contractor can give rise to both an extension of time and delay costs.
When AS 4000 is used
- Commercial and civil projects where the principal has a completed design
- Lump sum, construct-only procurement with a Superintendent
- Projects wanting a modern, widely understood standard form
- Head contracts intended to sit above an AS 4901 subcontract
The AS 4901-1998 subcontract
AS 4901-1998 (General Conditions of Subcontract). AS 4901-1998 is the construct-only subcontract companion to AS 4000, used to pass head-contract obligations down to subcontractors on a consistent basis.
Get advice on your AS 4000 contract
If you are about to issue, sign or administer an AS 4000 contract, early advice is far cheaper than a dispute. Christopher can review the contract and its special conditions, confirm which edition applies, and advise on the terms worth negotiating before you commit.
Common questions about AS 4000
What is AS 4000?
AS 4000-1997 is an Australian Standard setting out general conditions of contract for construction work. It is a construct-only head contract, meaning the principal supplies the design and the contractor builds to it, and it is administered by a Superintendent. It is one of the most widely used standard form contracts in Australia and the flagship of the modern AS 4000 suite.
What is the difference between AS 4000 and AS 2124?
Both are construct-only forms administered by a Superintendent. AS 2124-1992 is the earlier contract; AS 4000-1997 is the modern form that followed it. AS 4000 requires the Superintendent to act reasonably and in good faith, and reworked several mechanisms, while AS 2124 in its unamended form tends to give the contractor broader grounds for an extension of time. Both remain in use, so the right choice depends on the project and the parties.
Does AS 4000 need special conditions?
Almost always. AS 4000 is a balanced starting point, but it is rarely signed unamended. Special conditions adjust risk allocation, payment, time, insurance and dispute resolution to the specific project. Because a poorly drafted amendment can undo the balance of the standard form, the drafting and review of those special conditions is where careful advice pays off.
Has AS 4000 been updated, and which edition applies?
Yes. AS 4000-1997 remained the standing edition for many years and is the version most contracts still refer to. Standards Australia has since published a modernised edition, AS 4000:2025, which keeps the familiar structure but updates several mechanisms, most notably a more flexible dispute resolution regime. The edition that applies is whichever one your contract adopts, so it is important to confirm the edition and any amendments before you rely on a particular clause. See the dedicated AS 4000:2025 page for what changed.
Keep reading
Australian Standard contracts overview
How the AS suite fits together and which standard form suits your project.
ContinueAS 4000:2025 edition
The modernised 2025 edition of AS 4000 and what changed from 1997.
ContinueAS 2124 contract advice
The earlier construct-only form, and how it compares with AS 4000.
ContinueAS 4902 design and construct
The design and construct form for when the contractor also designs.
ContinueContract review before signing
A dual-qualified review of the contract and its special conditions before you commit.
ContinueContract administration advisory
Advice on the Superintendent role, certification, variations and extensions of time.
ContinueDiscuss your contract
Talk through your standard form contract with a solicitor who is also a registered architect.
Continue