DRAINAGE problems at the crisis-hit Edinburgh children's hospital were flagged up by senior executives nearly a year ago.

Minutes from a meeting of NHS Lothian's Finance and Resources Committee in September 2018 refer to "residual technical issues" blighting the project "with the key issue being around drainage systems".

The £150 million facility was originally scheduled to open in 2017 but it is now unclear when it will admit patients after a last-minute inspection revealed ventilation flaws in critical care, scuppering plans to open the hospital on July 9.

Drainage issues which were causing a flooding risk have also been identified, but Health Secretary Jeane Freeman said these had been resolved and an NHS-led safety review was "on track" for completion in September.

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It comes as a retired architect who helped draw up the original blueprint for the hospital told the Herald the design was flawed from the beginning.

Robert Menzies said clinicians came under pressure to sign off on an exemplar design in 2011 that even the architects were unhappy with because delays were turning the project into a "political hot potato".

Mr Menzies said the template was rushed through following the decision to switch from a publicly-funded to a non-profit  distributing (NPD) model, where the project would be awarded to a private consortium.

Mr Menzies said: "Part of the problem was that there was too much inexperience in a lot of the teams designing departments. It would come to me for comment and I'd be saying 'you need to change that, you can't do this'.

"So instead of doing tweaking you were doing major redesign without getting the tweaking done, and the clinicians were being put in a position where they were under pressure to sign it off because we need to get on and get it out to bidders

"I said we could do with another three months - but the decision was made to get it out to bidders and leave it up to them to fix these mistakes.”

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In any major building project, architects are hired to draw up an exemplar design which should meet all essential criteria, with bidders required to cost and illustrate how they would deliver it and any changes or additions they would make.

However, Mr Menzies said NHS Lothian's managers were subsequently reluctant to accept bids that varied in any way from the exemplar design for fear of further delays.

He said: "The company I was with, including myself, were one of the bid teams. We spent a lot of time getting rid of a lot of these problems only to be told 'no, we want a copy of the [exemplar] design'.

"That's where it started to get daft because we've sorted a problem and been marked down for it."

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His firm was one of three bidders but lost out to the winning consortium, IHSL Ltd.

Mr Menzies said he is baffled that it has taken so long to identify and address drainage problems, but questions why it had been positioned beneath the hospital when the site is on a floodplain.

He said: "You should try to avoid putting a drain under a hospital in the first place because if it overflows, it overflows into the hospital.

"You want your drainage coming down and going beyond the footprint of the hospital where you can get access if anything goes wrong, without it overflowing into a corridor in the hospital which is a major problem.

"In the bid that we did we took a lot of stuff out of the basement, including car parking, because there was a worry about flooding. But I think we might have got marked down for that.

However, Mr Menzies said suggestions the entire facility might have to be ripped down to fix it was "hysterical nonsense".

He said: “The question is whether it’s one point that's faulty or does whole drainage system need replacing? You don't need to demolish the whole building to do that, but if it’s something repeating across the entire system that's a major problem.

"But it begs the question, how was that allowed to happen?”