How adjudication works in Western Australia
Adjudication is the fast, binding-for-now determination of a payment dispute under the Building and Construction Industry (Security of Payment) Act 2021 (WA), built for cash flow, not courtroom perfection. In Western Australia, applications go under the 2021 Act, through authorised nominating authorities; under the old CCA 2004, an application must be made within 90 business days of the payment dispute arising. The strongest position a subcontractor can hold is a valid payment claim the builder never answered with a payment schedule: the full amount becomes payable and the builder's defences are barred.
Western Australia's regime, in 90 seconds
The sequence
A valid payment claim starts everything. The builder has 15 business days to serve a payment schedule saying what it will pay and why. From there, two roads: a schedule that disputes your claim leads to an adjudication application; no schedule at all makes the full amount a debt due, and in that case the builder is barred from raising its reasons before the adjudicator.
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.
What wins at adjudication
Adjudicators decide quickly and on the documents. The winning inputs are boring: a claim that identifies the work and the amount, served on time to the right party; contemporaneous records (site diaries, notices, delivery dockets, emails anchoring dates); and a claimed amount built up transparently.
Most of that is decided months earlier, on site, by habit. The subbies who win at adjudication are the ones whose paperwork was already in order when the dispute started.
Which WA Act covers your contract
Start with the date the subcontract was entered into. Contracts from 1 August 2022 sit under the Building and Construction Industry (Security of Payment) Act 2021: you serve a payment claim, the builder has 15 business days to serve a payment schedule, and a disputed or missing schedule opens the adjudication route through an authorised nominating authority, which appoints an adjudicator from the register kept by Building and Energy. Contracts signed before that date stay under the Construction Contracts Act 2004: there is no payment claim and payment schedule exchange, a payment dispute arises when a claim is rejected or unpaid at its due date, and the application to a registered adjudicator must be made within 90 business days of that dispute.
The two regimes do not mix. A notice drafted for the 2021 Act served on a 2004 Act contract, or the reverse, is the most common way a WA application fails before anyone reads the merits. Building and Energy publishes the list of authorised nominating authorities and registered adjudicators for both regimes, and issues certified copies of determinations when one has to be enforced in court.
Unlike Queensland, WA does not publish determinations with the parties named, so there is no public register to search a builder's adjudication history. The public record for a WA builder is the Supreme Court list and AustLII, where challenged or enforced determinations appear as judgments.
Where to apply
Building and Energy, WA (DEMIRS), authorised nominating authorities. Which Act applies depends on when the contract was entered into (before/after 1 August 2022).
Exact deadlines and application mechanics should be verified against the Act and current guidance before filing. They're strict, and a defective application wastes the strongest lever you have. Official guidance: https://www.wa.gov.au/organisation/building-and-energy
Adjudicate Pro: what an adjudicator would likely award under Western Australia law, and whether to apply.
Assess my payment dispute freeFrequently asked questions
The contract date decides it. Subcontracts entered into on or after 1 August 2022 are under the Building and Construction Industry (Security of Payment) Act 2021, with payment claims, payment schedules and adjudication through an authorised nominating authority. Subcontracts signed before that date remain under the Construction Contracts Act 2004, where a payment dispute starts a 90-business-day window to apply to a registered adjudicator. Check the execution date before you serve anything.
Determinations typically land within about 10 business days of the adjudicator accepting the application. The regime is built to move at cash-flow speed, not litigation speed.
No. The regime was designed for parties to run themselves, and many subcontractors do. For larger or messier disputes a construction lawyer's review of the application is cheap insurance. Either way, the evidence that decides it is the paperwork you kept on site.
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.