The new building in Little France was due to open in July but was delayed by health secretary Jeane Freeman after it was found that the ventilation system within the critical care department required further work to meet national standards.

The Auditor General for Scotland said two reviews already carried out into the troubled facility have been unable to establish “a number of issues”, including:

• why specifications in the hospital’s 2012 tender papers were inconsistent with national ventilation guidelines for critical care areas - an error that led to confusion
• and why a series of opportunities to spot the error - which caused the delay to the 2019 opening of the hospital - were missed.

Audit Scotland’s own report, published on Wednesday, sets out the facts as they are known and draws on the reviews already carried out by KPMG and NHS National Services Scotland, as well as NHS Lothian’s annual audit report.

The KPMG review found that the main issue with ventilation in critical care stemmed from an error in a document produced by NHS Lothian at the tender stage in 2012. This was despite the requirement to also adhere to relevant technical guidance. The second and final part of a review into compliance of all building systems at the hospital and Department of Clinical Neurosciences (DCN) identified remedial work required within fire and electrical systems prior to occupation and opportunities for other improvements.

Audit Scotland said its report, which comes ahead of a public inquiry into the hospital project, raises broader issues for consideration, including:

• the clarity and application of the national ventilation guidelines, and how they were managed
• the effectiveness of the oversight and scrutiny of the project
• the role of all the parties involved, including project company IHSL’s construction arm, Brookfield Multiplex, who also built the Queen Elizabeth Hospital in Glasgow.

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, and the public inquiry may want to consider why that happened after similar issues had emerged around the building of schools in Edinburgh.

“It would also be beneficial to understand the role played by all the parties involved, and to explore why the issues that emerged at Glasgow’s Queen Elizabeth hospital didn’t prompt greater scrutiny in Edinburgh.”

Health secretary Jeane Freeman said: “I’d like to thank Audit Scotland for this report, which recognises the crucial role of the independent public inquiry into issues at the RHCYP in Edinburgh and the QEUH campus in Glasgow.

“The KPMG and NSS reports into the RHCYP will provide a significant amount of the underpinning evidence for the inquiry, alongside the ongoing independent review into the delivery and maintenance of the QEUH.

“As I announced last month, Lord Brodie will chair this independent public inquiry, which will help us learn lessons from recent issues so they are not repeated in the future.

“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.”

She added: “NHS Lothian continue 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.”

A spokesman for the Royal College of Physicians of Edinburgh said: “Serious failings at hospitals in Scotland in recent years have highlighted the need for quality governance in healthcare, with patient-centred decision making at its heart.

“Indeed, Audit Scotland have indicated some clear oversights and have highlighted questions around levels of scrutiny in their latest report.

“The College believes that the Audit Scotland report further highlights the need for reinforced governance arrangements.

“In Scotland, this is an area where we’d like to see the Scottish Government play a leading role, working with NHS Boards and clinicians to develop more meaningful performance indicators in relation to the quality of care.”

It was revealed yesterday that NHS Greater Glasgow and Clyde has commenced legal action against Brookfield Multiplex regarding its work on the Glasgow facility.