Reserved Judgment — unpaid invoice — construction contract — unjust enrichment. The plaintiff sought to claim for an unpaid invoice totalling $14,518.48, which had been issued to the defendants under their contract for the construction of the defendant's new home. The construction contract was for $468,387; broken down into 16 staged payments. In dispute was the 12th staged payment designated to cover “all interior decoration or coatings”, amounting to $14,518.48. The defendants refused to pay, in spite of the fact that stage was complete, because an earlier stage (“foundations and floor structure”) had been paid for but was not complete due to disagreements between the parties. The defendants sought to set off the payment of the 12th stage against the already paid for incomplete stage. The defendants sent a letter advising they were withholding payment;the plaintiff responded that, as per the contract, they would suspend working on the project until payment was made. Lawyers for the defendants requested work resume, mediation failed, and so the defendants gave notice they were cancelling the contract. They subsequently had another construction company complete the home. The defendants also filed a counterclaim for $23,225.40, being the difference between the total amount they spent to build the house and the lesser fixed price at which Envisage contracted to build it. The Judge, upon considering the contract, the facts, and any potential unjust enrichment, held that the defendants must pay $6,997.48 to the plaintiffs for unjust enrichment. This reflected the invoiced sum of the 12 staged payment, less the slab insulation that was used and installed in the property. The counterclaim was dismissed. The plaintiff sought indemnity costs pursuant to clause 63 of the contract. The Judge directed the parties to make written submissions on costs. Judgment Date: 22 May 2018.