Bill for London’s 24-hour museum goes through roof

The cost of creating a new home for the Museum of London has leapt by a third to £332 million, making it Britain’s most expensive cultural building project.

Boasting artefacts ranging from prehistoric axe heads to a giant “fatberg” from the capital’s sewers, the museum hopes to become one of London’s top ten attractions when it relocates from Barbican to Farringdon.

The £80 million increase in the budget since the end of last year has been attributed to the state of disrepair of the disused Smithfield market buildings that the museum is taking over. The extra cost has been taken on by the City of London Corporation, which plans to create a “culture mile” in the northwest corner of the financial district and will remain the museum’s landlord.

The new home will enable the museum to show off more of its collection of seven million items, including the silk vest worn by Charles I for his execution in 1649 and the Cheapside Hoard, a 500-piece collection of jewellery from the 1600s that was found by workmen in 1912.

The museum will be open up to 24 hours a day to attract clubbers and commuters and is expected to open in 2024.

Releasing the latest designs by the architects Stanton Williams, Asif Khan and Julian Harrap yesterday, Sharon Ament, the museum’s director, said: “It’s a really complex site, with the Thameslink railway line running under it, and the buildings haven’t been occupied for 30 years, but the costs are now under control and when it opens it will be just as evocative and compelling an attraction as the Tate Modern.”

The designs, which include an underground gallery, a sunken garden and a large, light-filled dome, will be put on display in Smithfield on Friday before a planning application in the autumn.

The extension to Tate Modern, which opened in 2016, cost about £266 million and a concert hall planned at the Museum of London’s old Barbican site is set to cost £288 million.