New South Wales
In NSW, the variation isn't real until it's written and signed.
Home building contracts in NSW carry a term the parties never negotiated: any agreement to vary the work must be in writing and signed by or on behalf of each party. It's in the Home Building Act itself. Here's what that means on a Tuesday afternoon, what the paperwork needs, and what happens to variations that skipped it.
Written AND signed, by law Applies to contracts over $5,000 E-signatures count
01 — The rule
Schedule 2, clause 1(2). One sentence, whole habit.
Residential building work in NSW runs under the Home Building Act 1989. Contracts above $5,000 must be in writing, and the Act writes mandatory terms into them through Schedule 2. Clause 1(2) of that Schedule is the variation rule: any agreement to vary the contract, or the plans and specifications, must be in writing and signed by or on behalf of each party.
Read that again as the trade reads it: not “should be documented”, not “best practice” — must be. It applies whether the variation is $400 of extra decking or $40,000 of re-work, and it applies to the customer's verbal requests just as much as to yours.
02 — The paperwork
What the written variation needs to say.
What changed
The work being added, removed or substituted, described plainly enough that neither of you can later claim surprise.
The price
The amount, including GST — or how it will be calculated if it genuinely can't be fixed yet.
Both signatures, dated
Clause 1(2) requires signature by or on behalf of each party. Electronic signatures are recognised in NSW under the Electronic Transactions Act 2000, so a phone signature qualifies.
The industry contracts do the plumbing for you: the HIA and Master Builders NSW contracts carry variation clauses to the same effect, and NSW Fair Trading's own standard contracts spell it out too. Whatever form you use, the sequence is fixed by the Act — signed paper first, varied work second.
03 — Skipping it
What happens to the variation that never got written.
NSW tribunals and courts have repeatedly dealt with builders who did extra work on a nod. The pattern in the decisions is uncomfortable: without a written, signed variation the contractual claim generally fails, and the builder is left arguing for the reasonable value of the work instead — quantum meruit — which means arguing value after the fact, with the customer motivated to value it low.
None of this is legal advice, and live disputes belong with someone qualified. But the practical reading is hard to escape: in NSW, the paperwork isn't protection you add for cautious customers. It's the difference between having a claim and having a story.
04 — Doing it fast
The compliant version takes about a minute now.
The old excuse was friction: paper on site meant printing, signing, scanning, losing. That excuse has expired — a variation written on your phone and signed by the customer on theirs satisfies clause 1(2) completely, timestamps included.
That's ScopeLock's entire job, so bias declared: describe the change, send the link, the customer signs on their own phone — no account, no app — and you both keep a PDF neither side can edit afterwards. Free under A$500. Whether it's us or a carbon-copy pad, the rule is the same: in NSW, written and signed beats remembered.
Straight answers
Questions people actually ask.
Do all NSW variations have to be in writing?
Where the Home Building Act applies — residential building work under a written contract above $5,000 — yes: Schedule 2, clause 1(2) makes written and signed signatures-by-each-party a required term for varying the work or its plans and specifications. Jobs below the threshold aren't handed the same statutory term, but the same habit protects you there too.
Is a text message approval enough in NSW?
It's evidence something happened, but it usually fails the clause on its own terms: the requirement is a written variation agreement signed by each party, and a thumbs-up against a photo of a wall isn't a signature on an agreed wording. A signed electronic variation document meets the requirement squarely — e-signatures are recognised under NSW's Electronic Transactions Act 2000.
What is quantum meruit?
A fallback claim for the reasonable value of work done when there's no enforceable contract covering it. For an unwritten NSW variation it's the only card left, and it's weaker than the contract claim the paperwork would have given you — the value gets argued after the work is done rather than agreed before it. This page isn't legal advice.
Which NSW contract forms already cover variations?
The standard ones all do: NSW Fair Trading's own contract forms carry variation clauses (clause 13 in the larger-works contract, clause 4 in the small-jobs form), and the industry contracts from HIA and Master Builders have their equivalents. Using one doesn't remove the obligation — it documents it.
Method
Where these answers came from.
Vendor screens and features are taken from each publisher's own website or help centre on the date shown. Nothing here is sponsored and no vendor has reviewed this page.
If something's changed, tell us and we'll fix it — an out-of-date guide is worse than none.
The next one's coming
The next “can you just” is already on its way.
Price it on your phone, they sign on theirs, you both keep the PDF. Under A$500 it costs you nothing, ever.
No card, no trial clock. Your customer doesn't need an account.