Parliament’s financial watchdog has concluded that the taxpayer saved 2% by using the private finance initiative to build a new embassy in Berlin.

The National Audit Office said in a report this week that the total cost of £49.8m for constructing and operating the building over 30 years represented a saving of £1m, compared with conventional procurement.

The report praised the way the Foreign Office managed the PFI contract, but noted that “the scope for proposing design innovations was limited”, as a scheme design had already been decided before bids were invited.

Lawrence Bain, partner of the competition-winning architect, Michael Wilford and Partners, also noted that the PFI process lengthened the development process by one year.

Bain said: “We share the NAO’s opinion that the consortium made quite a good job of it. But there would have been more prestige for the embassy if the building had been completed earlier.”

The embassy, which will be opened by the Queen on 18 July, was developed by a consortium of German contractor Bilfinger & Berger and the American-owned facilities manager Johnson Controls. Wilford was novated to the contractor.