This appeal is from a judgment against the defendant in a suit to recover damages for breach of a contract calling for plaintiff to design and furnish the interior of the defendant’s home in return for a fee equal to a specified percentage of the cost of the supplies used in the *499project. The case was tried before a judge sitting without a jury. The defendant complains on appeal that the trial court failed to require a sufficient foundation for the admission of certain invoices offered by the plaintiff. He also contends that there was no competent evidence to support the judgment. Held:

Assuming arguendo that defendant’s objection to the documents had merit, we find the error harmless in that the judgment was supported by other evidence. In addition to presenting the invoices, the plaintiff testified without objection that, based on his records, he had costs of $59,484.32. He testified that the defendant owed him the amount of these costs, plus a fee of $11,896.86, representing 20 percent of the costs, as agreed upon, plus $2,287.84 in sales tax. The total of these figures is $73,669.02. The trial court awarded the plaintiff $12,041.02 representing this entire total, less a credit of $61,628 for payments previously made by the defendant. “[W]hen a case is tried before a judge without a jury, there is a presumption that the judgment was rendered only upon the competent and legal evidence before him and if any illegal evidence was admitted it does not require a new trial.” United Rentals Systems v. Safeco Ins. Co., 156 Ga. App. 63, 65-66 (273 SE2d 868) (1980).

Judgment affirmed.