Just because you are pursuing a claim for unjust enrichment does not mean you don’t have to still prove your damages with a reasonable degree of certainty. You ABSOLUTELY do:

Under Florida law, unjust enrichment damages must reflect the reasonable value of the plaintiff’s labor and costs expended for the benefit of the defendant or the value of the economic benefit that the plaintiff had conferred upon the defendant. While mathematical precision is not required, damages must be ‘measurable and quantifiable’ and supported by a ‘fact-based chain of reasoning’ so as to avoid conjecture.

Alvarez v. All Star Boxing, Inc., 50 Fla.L.Weekly D913a (Fla. 3d DCA 2025).

While Alvarez is a non-construction case, it deals with unjust enrichment which comes up in construction disputes. Here, unjust enrichment damages were awarded to the plaintiff. An appeal was taken because the defendant claimed the evidence didn’t support or link to the unjust enrichment damages that were awarded to the plaintiff. The appellate court agreed finding there was no ‘fact-based chain of reasoning” that could link the damages awarded (with relevant citations relative to damages that must be proven to support an unjust enrichment claim).