A MISTAKE which has delayed the opening of Edinburgh's new children's hospital could have been avoided if a different bidder had been chosen to build the facility.

A report by auditors Grant Thornton found that "human error" had resulted in too few air changes being designed into the critical care ventilation system at the new Royal Hospital for Children and Young People (RHCYP) in Edinburgh.

The blunder, which stipulated four air changes per hour instead of the required 10, was made in an "environmental matrix" document drawn up in 2012.

The auditors described the mistake as a "human error in copying across the four-bedded room generic ventilation criteria into the critical care room detail".

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The error only came to light in June 2019, when an eleventh hour inspection prior to the hospital opening discovered that ventilation did not meet infection control needs. The opening was halted pending £16 million of remedial works.

The matrix provided a design blueprint when the project was put out to tender, with Brookfield Multiplex awarded the design and build contract.

However, the auditors' report - commissioned by NHS Lothian - notes that another of the three bidders picked up on the ventilation error.

It states: "The changes included by this bidder did correct the environmental matrix to record critical care as requiring 10 air changes per hour. Other corrections were also made."

The report does not name this bidder. 

The auditors said this was one of a string of "missed opportunities" over seven years to avoid the mistake, but noted that the other bidder's correction "did not raise questions on the matrix".

Grant Thornton's report adds that Brookfield Multiplex - who also built the Queen Elizabeth University Hospital and Royal Hospital for Children in Glasgow - had "scored the lowest on the mechanical and engineering submission" out of the three bidders, and "appeared to lack detail compared to other tenders received".

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The construction of the RHCYP and the QEUH campus, which has also undergone remedial work after problems were uncovered with its ventilation design, is now subject to a QC-led public inquiry.

In its overall conclusion, the review said there had been a "collective failure from the parties involved".

Conservative health spokesman Donald Cameron said the findings were "both astonishing and appalling", adding: "It must be one of the most costly errors in the history of the NHS in Scotland."

Calum Campbell, chief executive of NHS Lothian, said the recommendations of the auditors "will be implemented within the agreed time frames to ensure that future capital projects will benefit".

The department of clinical neurosciences and children's outpatient services on the site have now opened, but there is no date yet for a full hospital opening.

A Scottish Government spokeswoman said: "The safety and wellbeing of all patients and their families is our top priority and should be the primary consideration in all NHS construction projects."