Despite the design revisions, the project source says the cost of the building should not exceed £400m, as a £11.8m contingency fund has been in place to cover the increases.
The revelation in Building comes as the Fraser inquiry continues to try and establish how Holyrood ran 10 times over budget and fell three years behind schedule. This week a disgruntled former project manager, Bill Armstrong, shed light on the machinations behind Holyrood.
Armstrong, who assessed the architects bidding for the Holyrood prize, that the warnings he gave to the Scottish Executive were ignored. "When you continually report bad news, you become associated with it," he lamented. "I think there was a feeling in the Scottish Office hierarchy that if I went, the bad news would go away too".
Armstrong quit as project manager in December 1998 when he felt the project was going badly wrong. This week Armstrong, who has been an architect for over 40 years, raised some serious questions about the procurement process and the selection of the late Enric Miralles as architect for the job.
Armstrong had expressed his reservations about Miralles and his international firm EMBT at the very start. When the Catalan architect was on the shortlist of 12, Armstrong said he made his reservations clear to the selection panel. He did not feel that Miralles was prepared to devote enough time to the scheme, and when he saw the designs he expressed doubts about whether the parliament could be built within the £50m budget.
Such were Armstrong's concerns that he told the Scottish Office's chief architect John Gibbons that Miralles should be sacked six months after he won the contract in July 1998. In a memo to Dr Gibbons he said: "I have reservations and doubts on their ability to produce the building we envisage within the brief, context and budget restraints."
The appointment of contractor Bovis was also questioned by Armstrong. He said that Bovis's bid was £1m more than the lowest bidder, Sir Robert McAlpine and that its appointment broke the Scottish Office's own building directive. When asked by John Campbell, QC counsel for the inquiry whether he was concerned about the legality of the move he replied that "it was entirely wrong".
Armstrong also told the inquiry that Miralles made it onto the shortlist despite not having the required £5m insurance cover. His PI insurance was £400,000 and he was only able to meet the criteria once he had linked up with Scottish architect RMJM.
There have also been question marks over the way the architectural competition was run. David Wilson, director of the Manifesto Foundation for Architecture based at Napier University, said that at least one big-name architect should have been on the judging panel to encourage international practices to enter. Wilson says that was why only 70 practices entered, rather than the 300-400 entries which international competitions usually attract.
The competition was organised by Scottish civil servants, which Wilson said this was very unusual. He believes that it should have been handled by a professional body such as RIBA or the Scottish equivalent, the Royal Incorporation of Architects in Scotland.
The last word goes to Armstrong who was pessimistic about Holyrood even before the Miralles' selection. He believed that the competition process had led to a paltry standard of entries. Of the five firms on the final shortlist he said: "I find it hard to believe that such an allegedly massive architectural talent cannot produce one approach which is convincing and acceptable."