Variations to ACT Residential Building Contracts

What it is

A variation is a change to the scope, quality or timing of work after the contract is signed. It is the single largest source of residential building disputes in Australia, which is why most jurisdictions legislate it: variations must be in writing, must state a price, must be signed before the work starts, and a builder who ignores that may be barred from recovering.

The ACT does none of this. The question is not what the Building Act 2004 (ACT) requires of a variation. It is that the Act has never turned its mind to variations at all.

The Building Act 2004 does not legislate variations

Read the Act end to end and the word variation does turn up. Every use of it concerns varying a Ministerial exemption for a regulated swimming pool under section 83E. Not one concerns a change to a building contract.

There is no requirement that a variation be in writing. No list of what a written variation must contain. No notice period. No bar on a builder recovering for an unwritten variation, and therefore no relief provision either, because there is nothing to be relieved from. No cooling-off on a variation, no cap on variation margin and no offence.

For a residential building contract in the ACT, a variation is governed by the general law of contract and by whatever the parties wrote. That is the entire regime.

The machinery exists but is switched off

This is not an oversight the Territory cannot fix. It already built the lever.

Section 89C (1) of the Building Act 2004 lets a regulation prescribe a standard condition for a residential building work contract, and the meaning of a prescribed term. Section 89C (2) makes it a strict liability offence to enter a contract that omits a prescribed condition, with a maximum penalty of 10 penalty units. A mandatory variations clause is precisely what that power would carry.

The Building (General) Regulation 2008 (ACT) prescribes no standard condition. Section 38B prescribes prohibited conditions about certifier control, and that is the only limb of Division 6.2A doing any work. Until a regulation is made, section 89C is an empty frame.

The verbal instruction trap cuts both ways

In a state that requires variations in writing, an oral instruction is usually the builder's problem, because the builder may be unable to recover for it. In the ACT the risk sits on both sides, and the owner carries more of it than they expect.

With no statutory writing requirement, an oral variation to an ACT building contract is enforceable like any other oral agreement, unless the contract itself says otherwise. A homeowner who says "yes, do it" on site can be sued for the cost. There is no statutory provision to hide behind. The builder's risk is the mirror image: no paperwork means proving the owner agreed at all, and to what price.

The only thing standing between an ACT owner and a bill they did not budget for is the variations clause in their own contract. If the contract requires variations to be in writing, signed and priced before work begins, that clause is doing statutory work in a jurisdiction that has no statute.

Two consequences people miss

• The approved plans. Section 88 (2) (b) warrants that the work is carried out in a proper and skilful way and in accordance with the approved plans. A variation that moves the work away from the approved plans without an amended building approval does not just create a payment dispute. It puts the builder offside the statutory warranty.
• The insurance. Cover is calculated against the cost of the work, and section 91 (2) values the work at its cost for premium purposes. Variations push the cost up. ACT Government guidance tells owners to check the policy or fidelity certificate is accurate as to the cost of the work, because a policy written against the original price may not stretch over the final one.

What the regulator says and what the ACT compares to

Access Canberra and the ACT planning guidance treat variations as a contracting discipline rather than a legal right. Be clear about arrangements for variations before you choose a builder. Make sure the contract records the total price and the provisions dealing with variations. Specify inclusions down to small items so they cannot be substituted without agreement. Settle those choices before signing, because changing them mid-build costs money.

The ACT is not unique here. South Australia leaves variations to the contract too. But an owner arriving from NSW, Victoria or Queensland should assume nothing carries across. In the ACT, the protection is not in the Act. It is in the clause, or it is nowhere.