In a statement to MPs, Liberal Democrat MP John Thurso said Deloitte Real Estate would lead a consortium, which will also include AECOM and HOK, to review options for restoration and renewal of the palace.
Necessary work is likely to include removal of asbestos, updating of ancient electrics and lifts, modernisation of heating and ventilation, and repairs to leaky roofs. Subsidence is also causing the Elizabeth Tower, containing Big Ben, to tilt. Final decisions will not be made until after the 2015 election.
A maximum price for the Deloitte investigation contract has been set at £2,019,295. A fixed price will be determined two months into the work, Mr Thurso said, once the new contractors are familiar with existing extensive survey work. The final bill could be lower but cannot be higher.
Mr Thurso, speaking on behalf of the House of Commons Commission, said his committee and the House of Lords House Committee had jointly agreed the detailed study was the next step in establishing the necessary work on the palace, which dates back decades and in some parts of the building centuries.
Mr Thurso said: "The palace will require very significant renovation in the years to come. The commission and the house committee recognised in 2012 that doing nothing is not an option. They accept their responsibilities as custodians of a great iconic building and the need to ensure its future. Selection of a preferred way forward is expected to occur during the course of the next parliament, not this one."
Options discussed in the past have included moving parliamentarians off site for a period to allow a complete refit to take place. Alternatively, a much longer programme of rolling work could take place around the work of MPs and peers.