MAJOR questions “remain unanswered” over the problems that delayed the opening of a £230 million children’s hospital, the public spending watchdog says.

The Royal Hospital for Children and Young People in Edinburgh was due to open in July, but Health Secretary Jeane Freeman stopped the move into the new facilities after final compliance checks disclosed the ventilation system within the critical care department did not meet the current standards.

NHS Lothian has paid £1.35m per month for the empty centre since February. Remedying the problems there and keeping the older facility open could cost NHS Lothian an additional £28m.

A new report by Audit Scotland says it is still unclear why opportunities to spot an important error in the ventilation system covering the critical care unit were missed. The watchdog said it does not know why original papers for the construction of the hospital were “inconsistent” with technical standards covering ventilation systems – and why this environmental matrix document was later changed.

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Work by the auditors KPMG sets out “a picture of human error and confusion over interpretation of the relevant specifications and guidance and missed opportunities to spot and rectify that error”, Audit Scotland said.

Caroline Gardner, Auditor General for Scotland, said: “It’s clear that the checks and balances around the construction of the new children’s hospital didn’t work.”

Freeman has already announced a public inquiry into problems at the new Royal Hospital for Children and Young People in Edinburgh and at the Queen Elizabeth University Hospital (QEUH) in Glasgow.

Brookfield Multiplex, a key contractor on the Glasgow build, is also part of QEUHIntegrated Health Services Lothian Limited (IHSL), the group appointed to design, build, finance and maintain the Edinburgh project.

Yesterday the Health Secretary said the reports would “provide a significant amount of the underpinning evidence for the inquiry, alongside the ongoing independent review into the delivery and maintenance of the QEUH”.

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She stated: “I have a statutory obligation to consult with the chair on the inquiry’s terms of reference and I will provide a further update to parliament early in the new year.

“In the meantime, NHS Lothian continues to provide high quality care from the existing sites, and I want to thank staff, patients and their families for their continued patience as we work to migrate services to the new site as soon as it is safe to do so.

“Patient safety will always be my top priority.”