Variations on Western Australia subcontracts: getting changed work paid
Most variation money is lost between the site conversation and the paperwork. The standard subcontract lets the builder direct variations unilaterally, gives you a short written-notice window (as little as 2 business days in contracts we've analysed) with an absolute bar behind it, and lets the builder value the work where rates don't apply. Under the Building and Construction Industry (Security of Payment) Act 2021 (WA), variation amounts claimed under the contract flow through the payment claim process like any other amount.
The three clauses that take the money
Unilateral direction: "the subcontractor must comply with all variation orders" - you're bound to do the work before the price is agreed. Positions builders have accepted: variations agreed in writing before they bind, or a cap (bound only within the general scope, up to a stated percentage of the contract sum).
The notice time bar: a direction you consider a variation must be notified in writing inside the window or the claim is lost - 2 business days appears in real contracts. And valuation: "reasonable rates as determined by the Contractor" puts the price of your work in the other party's hands; a schedule of rates incorporated into the contract, sitting high in the order of precedence, is the fix.
The WA angle
Under the Building and Construction Industry (Security of Payment) Act 2021 (WA), a variation amount claimed under the contract goes into your payment claim like any other amount - and if the builder wants to pay less, it has to say so in a payment schedule within 15 business days, with reasons it will be held to at adjudication.
Two regimes run in parallel: contracts entered into from 1 August 2022 sit under the 2021 Act (East Coast model), while older contracts stay under the Construction Contracts Act 2004 with its 90-business-day adjudication window - the contract date decides which set of rules you're under.
The 90-second habit
Before leaving site on the day anything changes: one email. "Confirming we discussed [the change] on site today. We're treating this as a variation. Formal notice and pricing follow within the contractual timeframe. Work proceeds on that basis unless you advise otherwise." It anchors the date, creates the record, and starts you inside whatever window the contract sets.
Clause-by-clause risk report against Western Australia security of payment law in about 90 seconds.
Scan my subcontract freeFrequently asked questions
Under standard drafting, yes - the direction binds first and valuation follows. That's why the pre-signature ask is a written-agreement requirement or a cap, and the on-site protection is same-day written confirmation of every direction.
Yes - variation amounts claimed under the contract flow through the Building and Construction Industry (Security of Payment) Act 2021 (WA)'s payment claim process, subject to your contract's notice requirements for the underlying entitlement.
General information for Australian subcontractors, not legal advice. Statutory deadlines change and have exceptions - verify against the Act and current guidance, or with a construction lawyer, before acting on them.