The Committee said it will challenge and test the work and conclusions of Deloitte and the Joint Select Committee of the two Houses on the restoration and renewal of the Palace.
Andrew Tyrie, chair of the Treasury Select Committee said, “This is one of the largest major restorations in the history of the public sector. Apparently, it is likely to cost at least £3.5bn over five to eight years.
“This can only be justified to taxpayers if Parliament and the public see the evidence required to make an informed decision.”
Deloitte published an independent assessment of a range of options, with costs and timescales, for the major restoration and renewal of the Palace in June 2015.
It estimated that the cost of the project, if carried out over the minimum period of five to eight years with a full evacuation of the premises, will be between £3.5 and £4bn.
The Joint Select Committee of the two Houses considered the findings of Deloitte’s Independent Options Appraisal and concluded that the lowest risk, most cost-effective and quickest option to undertake these essential works would be for all MPs, Peers, and staff to move out of the Palace temporarily in one single phase.
Tyrie wrote to David Lidington, leader of the House of Commons, in December to ask for greater clarity on the value for money of the project.
The Committee has now published a preliminary report on the restoration project saying it would look at whether reducing the scope of the renovations would save money.
“Given the enormous sums involved, it would be vital even in normal times that the case for the spending and its cost-effectiveness were thoroughly scrutinised and that the plans were rigorously challenged,” the report said adding, “It is even more important at a time of austerity, when restoration of the Palace will be competing for funds with many hard-pressed parts of the public sector.”
Tyrie added, “The Committee's inquiry into this hugely expensive project will challenge and assess the work and conclusions of the existing reports.”
Because of the extensive investigations already carried out, the Treasury Committee said its inquiry is likely to be relatively short and specific.
“Until such work has been carried out, it would be imprudent for Parliament to commit to a specific option," Tyrie said.
A spokesperson for Deloitte said, “A Deloitte-led consortium carried out an Independent Options Appraisal (IOA) outlining a range of scenarios for carrying out a major restoration and renewal programme for the Palace of Westminster.
"The IOA did not contain recommendations on which scenario to choose but was intended to enable Parliament to make an informed decision on a preferred way forward.”