Sir Robert McAlpine has been confirmed to carry out repairs on Big Ben’s tower as the estimated cost of the project has doubled to £61m, it has been revealed.
The work was originally projected to cost £29m following an estimate in spring last year. However, the total cost of the scheme to repair the Elizabeth Tower – including fire safety work costs – is now an estimated £61m.
Among the reasons for the increased costs is that the job will be “more complex” than first thought, the House of Commons’ authorities said.
It added that despite “extensive surveys”, the ground conditions proved to be more complex than first anticipated and will require extra work.
A total of £17.2m has been set aside, up from a previous estimate of £5.8m, to cover “optimism bias”, allowing for unexpected challenges on the job.
Sir Robert McAlpine had already been appointed to a £3.5m contract to oversee preconstruction and scaffolding works in November last year.
However, the award for the overall contract to McAlpine is likely to prove controversial, after Labour’s former business secretary Chuka Umunna raised concerns about the choice of contractor in parliament earlier this month.
Mr Umunna flagged the fact that McAlpine had been implicated in the blacklisting scandal.
However, new McAlpine boss Paul Hamer wrote to Construction News to say that McAlpine has a “zero-tolerance approach” to blacklisting and the controversial practice was now “firmly in the past”.
The House of Commons and Lords commissions voiced their disappointment at the cost increases to the Elizabeth Tower project and the “unreliability of the original estimate”, the authorities said.
In a joint statement, the clerk of the House of Commons, the clerk of the Parliaments and the director-general said: “We acknowledge that there have been estimating failures and we understand the concern of the commissions.
“In advance of tendering contracts, the initial high level estimates were set at a lower level to avoid cost escalation from the market.
“Subsequent estimates, using better data and more extensive surveys, better reflect the true likelihood of the costs.
“We believe that we now have a more accurate estimate of the cost of the works and will report regularly to the committees on the progress of work.”
It emerged last month that Big Ben’s famous bongs will fall silent until 2021 while the restoration works are carried out.