Scrutiny committee leader, councillor Michael Wilkes, damned the way in which senior councillors tackled the planned new facility and highlighted a 'surprising lack of clarity'.
Specifically, Wilkes claimed in the 174-page report that questions were still to be resolved regarding the form and quality of the build in any two-site option.
According to the report, RRP director Graham Stirk has questioned the council's belief that a split-site option would be cheaper than RRP's own plans.
Stirk told the committee that it was not possible to say that two buildings of the same quality are cheaper than one.
The architect is quoted as saying: 'Economies of scale are essential for bringing costs down. The facade equates to 30 per cent of costs while the central plant is 30-35 per cent of the total cost, so duplicating them cannot be cheaper.'
In addition RRP, described as 'extremely passionate about its work' on the scheme, told the council that is was impossible to regenerate Eastside without a library there.