Variations to QLD residential building contracts

What a variation is

A variation is any agreement between a Queensland builder and homeowner to change the scope, materials, finishes or price of work that was set out in the original regulated residential building contract. Variations come up on almost every project.

The QBCC Act takes a clear position: variations to regulated contracts must be in writing and signed by both parties before the variation work is started.

The legal rule

Schedule 1B of the Queensland Building and Construction Commission Act 1991 (Qld) requires variations to a regulated residential building contract to be in writing, signed by both the builder and the homeowner. The variation must include sufficient detail to identify the work, the price impact and the time impact on the contract completion date.

A variation that does not meet Schedule 1B is not enforceable as a contract variation. The builder cannot recover payment for the work as a contract variation.

What a compliant variation looks like

A compliant variation:

• Identifies the work being added, removed or changed in enough detail that a reasonable third party reading later can identify what was agreed
• States the price impact: a specific dollar amount inclusive of GST or a clearly stated rate
• States any time impact on the contract completion date
• Carries the date and signatures of both parties

Email exchanges that exchange the variation in writing and are countersigned by reply can satisfy the written-and-signed test, but a single email saying "go ahead" without counter-signature is risky.

Consequences of unsigned variations

If a variation is not in writing and signed before the work is performed, the builder cannot rely on it as part of the contract. The Schedule 1B requirement is strict.

Limited equitable remedies such as quantum meruit may be available outside the contract, but they are harder to win and produce uncertain results at QCAT. Queensland courts have similarly narrowed quantum meruit pathways for unsigned variations.

The safest assumption: if it is not in writing and signed, it is not getting paid as a variation.

Comparison to NSW and VIC

QLD: written and signed required under QBCC Act Schedule 1B for regulated residential contracts (over $3,300).

NSW: written and signed required under HBA s 7E and Schedule 2 for residential building contracts.

VIC: written and signed required under DBCA s 38 for major domestic building contracts (over $10,000), plus a cost-estimate requirement where price is not fixed at signing.

All three jurisdictions enforce the same outcome: oral variations cannot be enforced. The Queensland trigger threshold is the lowest, so catches the most variations.

Practical advice for builders

Three habits make Queensland variation administration painless.

Use a numbered variation form. HIA Queensland and Master Builders Queensland standard contracts include or accompany variation forms with the right structure.

Document and sign the variation before performing the work. Once the work is done it is too late to argue about whether it was agreed.

Keep variations short and itemised. Five separate variation documents each signed is the cleaner audit trail than one bundled variation that mixes unrelated items.

Related entries

The QBCC framework for residential building contracts is in builder-licence-classes-qld and statutory-warranties-qbcc-qld. The cooling-off entry covers the parallel consumer protection mechanism (cooling-off-residential-building-contracts-qld). The NSW equivalent is variations-residential-building-contracts-nsw and the VIC equivalent is variations-residential-building-contracts-vic.