British members of parliament are to move out of the Palace of Westminster for six years while the building undergoes repairs, according to a leaked report. The papers, seen by The Times, indicate that MPs will take up residence at Richmond House – current home of the Department of Health – during the works, which are due to start in around four years' time.

Department of Health staff will also need to be relocated. Though a spokesman for the restoration and renewal committee, which is overseeing the repair works, said the process had "not been finalised".

According to the report, the committee ruled that MPs should not remain in the Palace of Westminster while the works are carried out. Although several options were considered, a full-scale move out of the building was recommended, as the cheapest option – leading to works costing around £4bn ($5.23bn) – and the quickest. If politicians remained in the building throughout the works – the option said to be favoured by former Prime Minister David Cameron – it would take around 30 years to carry out the project, which would then cost of £5.7bn.

If the move goes ahead, it will be the first time MPs have moved out of the 19th century building since the Blitz in 1941 when it was bombed. However, a number of issues with the building, including leaks in the roof, damaged stonework and mice infestations, need fixing in order to prevent further decay.

The work was recommended last year in an Independent Options Appraisal report by Deloitte Real Estate, AECOM and HOK, following a study warning of "irreversible" damage to the iconic building. The renewal programme director, Dr Richard Ware, highlighted the importance of the building and said "we face a massive challenge in securing its future".

During the works, both chambers – the Houses of Parliament and Lords – could be closed for as long as four years. Richmond House could potentially house a makeshift chamber over the course of that time, according to The Times.

MPs will however, be unable to consume any alcohol in Richmond House, at 79 Whitehall, after the building was leased in an Islamic bond scheme – a sukuk – two years ago. The sukuk, which was backed by then-chancellor George Osborne as a way of boosting investment from the Middle East, forbids the sale of alcohol within Richmond House.

A sukuk is a form of investment that complies with Islamic financial rules, which forbid earning interest on loans. So instead of investors loaning money which is repaid with interest, in a sukuk creditors take temporary ownership of a property, which is then leased back to its original owners at a profit.

The idea for MPs to nationalise a nearby pub, the Red Lion, during the works was floated but was shut down after its owners, Fuller's Inns, objected.

Palace of Westminster
The Palace of Westminster was last vacated by MPs in 1941PA