In a report published on Wednesday, parliament's spending watchdog looked at how much money was saved by funding the building using the PFI rather than traditional public procurement. It found that a fair comparison would have revealed that the PFI offered savings of only 0.4%.
The NAO's report implied that excessive costs were loaded on to the traditional procurement method, and questioned whether the measure should be relied on in making procurement decisions.
The report said: "Public sector comparators tell departments nothing about the benefits of alternative procurement methods and are subject to inevitable uncertainty, given the long timescales involved."
The comparators tell departments nothing about the benefits of each method
National Audit Office report
The NAO noted that £7m was added to the comparator for traditional procurement to take account of mothballing the old courts building for 25 years. The report questioned whether this was justified. It said: "The uncertainty inherent in a public sector comparator is illustrated in this deal by what might or might not happen to the Crumlin Road Courthouse over the next 25 years."
Despite its criticism of the comparator, the NAO praised the scheme's design, by architect Hurd Rolland Partnership. However, it noted that problems such as leaking roofs had yet to be resolved. It also claimed that the monitoring of the building's performance had taken second place to ensuring that it was operational as soon as possible.