AS 4000 general conditions of contract: what the form says, and why it matters to a subbie

AS 4000-1997 is the head contract between a principal and a builder on a large share of Australian construct-only projects. You will rarely sign it as a subcontractor, but it shapes the document you do sign: the liquidated damages rate, the defects period, the programme and the notice regime in your subcontract are usually written to sit underneath it. Knowing what the unamended form says gives you a benchmark, because the unamended form is noticeably fairer than most of what gets issued under its name. The form is copyright Standards Australia, so this page describes it rather than reproducing it.

What the drafting says

What it is

Construct-only head contract, published by Standards Australia in 1997. Its subcontract companion is AS 4901.

Who administers it

A Superintendent, appointed by the principal and required to act honestly and reasonably when certifying. Most subcontracts replace this role with the builder's own representative.

Payment

Certify in 14 days, pay 7 days later, in the unamended form. A state security of payment Act overrides any longer period written in by amendment.

Notice of claims

28 days, and not a bar, the unamended form asks for notice within 28 days, and says late notice exposes you to damages but does not bar or invalidate the claim. This is one of the most frequently amended clauses.

Extension of time

Claim within 28 days, and the Superintendent may extend time even where no claim was made. That discretion is routinely deleted by special condition.

Security

Retention or bank guarantee, whichever the annexure selects, with the default entitlement halving at practical completion.

Termination for convenience

Not in the standard form, termination for default needs a show cause notice first. A right to end the contract without cause only arrives by special condition.

Defects liability

Period set in the annexure, with a further period able to apply to rectified work.

Figures read from publicly published documents analysed in the Australian Subcontract Index corpus, August 2026.

How it compares

Set the unamended form beside the Index and the direction of travel is obvious: every identifiable time bar in the contracts we have analysed is drafted as an absolute bar, where AS 4000's own notice clause expressly is not.

Termination for convenience appears in roughly nine in ten contracts in the Index. It is not in the standard form at all.

The amendments are rarely about the project. They are a standing schedule the principal's or builder's lawyers attach to every job.

What to do about it

Ask what the head contract is, and how it was amended

If your subcontract refers to "the head contract", you are entitled to ask for the provisions that flow down to you: the liquidated damages rate, the defects period, the programme and the notice requirements. You cannot price a risk you have not been shown.

Use the unamended clause as your anchor

"The standard form this project is built on treats late notice as a breach, not a bar" is a stronger argument than "this seems harsh". You are asking for the published industry position, not a favour.

Watch the back-to-back clauses

Where the subcontract says your entitlement is limited to what the builder recovers under the head contract, your claim now depends on a document and a negotiation you are not party to. Ask for that wording to be removed or limited to genuine pass-through events.

The version you were handed is not the pattern. It's a specific document.

Templates get amended, schedules get filled in, and the risk lives in the details. The free scanner reads your actual document, every clause, benchmarked against real Australian subcontracts, in about two minutes.

Scan my contract free

Common questions

What is AS 4000 used for?

AS 4000-1997 is a general conditions of contract for construct-only work, used between a principal and a head contractor. It is administered by a Superintendent and is one of the most widely used head contract forms in Australia.

What is the difference between AS 4000 and AS 4902?

AS 4000 is construct only: the principal supplies the design. AS 4902 is the design and construct version, where the contractor takes on design responsibility. The two share most of their clause structure.

Does AS 4000 apply to me as a subcontractor?

Not directly. Your contract is the subcontract, commonly AS 4901 or the builder's own template. AS 4000 matters because the subcontract is usually drafted to pass its risks down to you, sometimes by reference to clauses you have never been given.

Is a late notice fatal under AS 4000?

Not under the unamended form, which says a late notice does not bar or invalidate the claim. It very often is fatal under the amended version you are actually handed, so search the special conditions for "condition precedent" and "barred".

Keep reading

General information for Australian subcontractors, not legal advice. Patterns describe publicly published documents analysed in the Index corpus, and standard forms are described from their published, unamended editions; the document you are handed governs, and only a reading of that specific document (or advice on it) can tell you your position. Written by Mat Kennedy at The Construction Contracts Co.