A spokesman for the assembly said claims made about the Richard Rogers scheme in the television programme Wales This Weekmade 'no sense' ( Rogers' Welsh Assembly 'cost proportionally more than Holyrood').
According to the ITV show, which was aired on Monday, the recently opened Cardiff Bay scheme cost £13,400 per m 2- compared to £13,060 per m 2for the over-budget Holyrood building.
However, a spokesman for the Welsh Assembly government said a direct comparison of the projects was not appropriate.
He said: 'It makes no sense to try to compare two bespoke public buildings which have come out of completely different briefs on the basis of cost per square metre alone.
'For example, in addition to the Chamber and Committee Rooms, Holyrood House includes a significant amount of lower-cost areas such as office space. Two thirds of the new Assembly building in Wales is accessible to the public, and has inherently higher costs due to factors such as increased security provision and the durability of finishes.'
The spokesman went on to explain that the budget for the Welsh scheme include far more than just construction costs.
He added: 'The estimated out-turn cost of the new Assembly building includes works undertaken to the external areas and the final section of the boardwalk around the Inner Harbour, as well as VAT on the construction cost, professional fees for the project management services, furniture, ICT and broadcasting equipment, art and other professional fees.'
The comments were supported by Stuart Pitteway, from the project's quantity surveyor Northcroft. Speaking to AJplus's sister website www.qsweek.com, Pitteway dismissed the comparison, saying the programme had not compared 'like with like'.