Variations are a systems problem, not a site problem

Builders rarely lose money on variations because they priced them badly. They lose it because the variation never made it from the conversation to the contract.

A client walks the frame and asks for an extra power point, a wider doorway or a different tile. The supervisor agrees and the work gets done, but weeks later, nobody can find the signed variation, the trade has invoiced for the extra time and materials, and the change never made it onto a progress claim.

It’s easy to treat this as a site discipline issue but more often, it’s a systems issue.

The cost of a missed variation

A variation that isn’t documented, priced and claimed is margin given away. It’s also a common starting point for disputes. In Victoria alone, the state’s free dispute resolution service closed an average of 5,780 domestic building cases a year between 2017–18 and 2022–23, according to the Victorian Auditor-General’s Office. An earlier survey found one in four residential builds involved a dispute between the homeowner and the builder.

Unrecovered money hurts cash flow too. In ASIC’s 2024–25 data for the construction industry, poor management of accounts receivable was nominated as a cause of failure in 19% of initial external administrators’ reports. Unclaimed variations are one of the quieter ways receivables go missing.

The law assumes the paperwork comes first

Every state sets rules for domestic building variations, and they generally expect the paperwork before the work. Queensland’s QBCC and Consumer Affairs Victoria, for example, both expect variations to be put in writing and agreed before the work starts. The consequences of skipping that step differ from state to state, but the principle is the same.

In Queensland, the QBCC says the contractor must give the owner the variation in writing within five business days of agreement, or before the work starts, whichever comes first. In Victoria, Consumer Affairs Victoria says a Variation Notice must be agreed in writing before work on the change begins, setting out the cost, the new contract price and the new completion date, with a narrow exemption for small changes.

The stakes in Victoria are high. In Mann v Paterson Constructions, the High Court considered a builder who carried out 42 variations requested orally, without the written notices required under the Domestic Building Contracts Act 1995. As the Court determined, a builder who hasn’t followed the notice process is generally not entitled to recover any money for an owner-requested variation unless the tribunal is satisfied of exceptional circumstances or significant hardship.

Again, the rules differ in each state but the point is simple: a variation that isn’t properly documented may not be recoverable at all.

Why it’s a systems problem

A single variation touches at least four records:

• The contract – scope, price and completion date.
• Purchase orders – the trades and suppliers who will do the extra work.
• The schedule – sequencing and any extension of time.
• The progress claim – when, and how, the client is billed.

When these live in different places, every variation depends on someone remembering to update three other records. It passes from supervisor to customer service, estimating, purchasing and accounts. Each hand-off is a chance for it to stall.

The trade side doesn’t wait. Under security of payment laws, such as the NSW scheme, contractors have a statutory right to progress payments for work delivered, with set processes for responding to payment claims. If a trade has done variation work, you’ll likely owe them – whether or not you’ve recovered the cost from your client.

What process discipline looks like

Builders who control variations well tend to share a few habits:

• No signature, no start. Variation work begins only once it’s written, priced and signed, with the exception of genuinely urgent safety work.
• Price it before it’s built. A standard rates list lets supervisors and customer service quote common changes quickly and consistently.
• One record drives the rest. Once signed, the variation updates the contract value, creates or adjusts the purchase order, flags any schedule change and queues the amount for the next claim.
• State the time impact. If the change affects the completion date, say so in the variation, and make sure this date change is reflected in your central system.
• Reconcile regularly. Consistently compare signed variations against purchase orders and claims, and chase anything unsigned.
• Report on what’s pending. Leadership should be able to see the value and age of unsigned variations by job quickly and simply.

Make it routine

Variations will always be part of building homes. Clients change their minds and sites frequently throw up surprises. What separates builders who profit from variations and those who absorb them is rarely what happens out in the field. It’s whether the variation, order, schedule and claim stay linked from the moment the change is agreed.

See how connected workflows can keep variations on track

ClickHome brings job information and workflows together across the building lifecycle, helping residential builders keep variations linked, reduce administration and protect margins.

Want to see how ClickHome can help your business work more efficiently? Get in touch.