AS 4903 subcontracts: the design and construct subcontract, and the risk that comes with it

AS 4903-2000 is the subcontract written to sit under an AS 4902 design and construct head contract, in the same way AS 4901 sits under AS 4000. It follows the same clause structure as AS 4901 and adds the design obligations. If you are handed one, the first question is not about payment or time. It is whether the design obligations in the document match the work you priced. The form is copyright Standards Australia, so this page describes it rather than reproducing it.

What the drafting says

What it is

Design and construct subcontract, published by Standards Australia in 2000 as the companion to AS 4902.

Design obligations

Passed to the subcontractor, for the subcontract works, including warranties about the design you produce.

Who administers it

The builder's representative, not an independent Superintendent. The person assessing your claims works for the other party.

Structure

Mirrors AS 4901, payment, security, time, variations, defects and default follow the same sequence, so the same amendments appear in the same places.

Usual amendments

Time bars, set-off, termination for convenience, the pattern recorded across the Index, plus wider design warranties.

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

How it compares

The Index finds absolute time bars in every contract where the drafting could be identified, and set-off without notice in almost all of them. An amended AS 4903 is no exception.

What is specific to this form: trades that do not design, such as installers working to shop drawings by others, are regularly issued it because the head contract is design and construct, not because their package is.

What to do about it

Decide whether you are a designer on this job

If you produce shop drawings to someone else's design intent, say so in the scope and limit the warranty to the accuracy of those drawings. If you design nothing, ask for the design clauses to be marked not applicable.

Line the scope up with your quote

A design and construct subcontract paired with a supply and install scope description can turn an install-only price into a full package. Attach your quotation as a contract document and give it precedence on scope.

Then fix the usual three

Notice as a requirement rather than a bar, written notice before any set-off, and a cap on liquidated damages at 5 to 10 per cent of the subcontract sum.

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.

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Common questions

What is the difference between AS 4901 and AS 4903?

AS 4901 is the subcontract for construct-only work and pairs with AS 4000. AS 4903 is the subcontract for design and construct work and pairs with AS 4902. AS 4903 adds design obligations and warranties for the subcontractor.

Do I need professional indemnity insurance under AS 4903?

If you accept design responsibility, the builder will usually require it, and you would want it regardless. If you carry no design responsibility, have the contract say so and the requirement should fall away.

Is AS 4903 fair to subcontractors?

The unamended form is reasonably balanced. As with AS 4901, the version you are handed has usually been amended, and fairness is decided by the special conditions.

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.