Delmere Holdings Pty Ltd v Green

Delmere Holdings Pty Ltd sought relief against the adjudicator's decision under the Construction Contracts Act 2004 (WA), claiming it was based on a jurisdictional error. The dispute centred around the interpretation of jurisdictional facts and whether the adjudicator misconstrued the statute, leading to an unjust enrichment in equity. The Supreme Court of Western Australia was tasked with determining the validity of the adjudicator's decision and whether it should be quashed.

The central legal issues before the court were whether the adjudicator had jurisdiction to make the decision and if there was a jurisdictional error that warranted relief under the common law or equitable principles. Specifically, the court needed to determine if the adjudicator misconstrued the statutory provisions, whether the error was one of jurisdiction or merely an error in the exercise of discretion, and if the adjudicator's decision resulted in an unjust enrichment 'in equity'. Additionally, the court had to examine whether the adjudicator's decision led to an unjust enrichment under the doctrine of quantum meruit and if there was an implied term that could be invoked.

In its reasoning, the court examined the adjudicator's decision and found that there was indeed a jurisdictional error. The adjudicator had misinterpreted the nature of the function and the extent of the powers under the Construction Contracts Act 2004 (WA), which led to an irrational or unreasonable conclusion. The court found that the adjudicator's error was not just an error in the exercise of discretion but a fundamental misinterpretation of jurisdictional facts. Consequently, the court quashed the adjudicator's decision and remitted the matter for reconsideration by a new adjudicator. The court also clarified that the principles of unjust enrichment in equity and quantum meruit were not applicable in this context, as the adjudicator's decision did not result in an unjust enrichment.