A major “decant” of 10,000 works of art at Buckingham Palace, including paintings, porcelain, tapestries and furniture, is being organised as part of its £369m refurbishment.

The whole of the east wing, off which the palace’s famous balcony is situated, will be emptied next April for long-overdue repairs, palace officials said.



Aides are hunting for appropriate storage for the items, which are part of the Royal Collection and many of which have been given to or collected by the royal family over centuries.



The upheaval is part of a 10-year project, which will include replacing vulcanised electrical wiring and ancient plumbing not updated since the 1950s and considered a fire risk.



Offices and 120 staff members will be relocated to other parts of Buckingham Palace, or nearby St James’s Palace. The Duke of York and Earl and Countess of Wessex, who have overnight accommodation in the wing, will be rehoused elsewhere in the palace.



A palace spokesman said there were 10,000 Royal Collection items in the east wing, which houses the Chinese dining room, the yellow drawing room, and the centre room, which leads to the balcony on which the royal family stand during the annual trooping the colour.



The spokesman said it would be “business as usual” and the trooping photo call should remain while work is ongoing, as well as the palace’s summer opening to visitors. There would be no external scaffolding throughout the works, with each wing refurbished in rotation.



On relocating the art, a spokesman said: “There are opportunities for loaning certain works of art, relocating some of the works of art to other parts of Buckingham Palace or other parts of the royal palaces estate.”



Aides were also looking for appropriate storage, “bearing in mind these are valuable works of art”, he said. Commercial storage was being considered.



Among the objects that will be moved are early 18th-century porcelain pagodas and a late 18th-century vase with mounts, from Jingdezhen in China, as well as a console table by Adam Weisweiler dated between 1787-90, all acquired by the future George IV when he was Prince of Wales.

The palace building contains more than 100 miles of old electrical cabling, 20 miles of heating pipework, 10 miles of hot and cold water pipework, 6,500 plug sockets and 5,000 light fittings.



Details emerged as the Queen’s annual expenditure was revealed. The monarch received a sovereign grant – money from taxpayers – of £76.1m in 2017-18. This included £30.4m specifically to fund the palace revamp.



The Queen’s income is calculated as a percentage of the Crown Estate profits two years previously. Originally set in 2011 at 15% of the profits, it was raised to 25% for 10 years in 2016 to cover the cost of the refurbishment.



The Prince of Wales’s private expenditure increased by about 40% after a busy year in 2017-18 with the engagement of the Duke and Duchess of Sussex and the birth of a third grandson, Prince Louis.



The Clarence House accounts, up to 31 March, were filed before the wedding of Prince Harry and Meghan Markle. Nevertheless, Prince Charles’s funding to pay for the activities of the Duke and Duchess of Cambridge and Prince Harry, and also including capital expenditure and transfer to reserves, rose from £3.5m to £4.9m.



His aides refused to give a breakdown, or indicate how much, if any, went towards funding the new Duke and Duchess of Sussex. Though the prince’s officials believe there is a level of transparency he is happy to go to, there is also a level of privacy they seek to protect.



The prince, whose annual income from the Duchy of Cornwall increased by 5% to £21.7m, also spent the most of all royals on official travel, after carrying out more than 600 engagements across 15 countries. His annual voluntary tax bill increased by 2%, after business expenses were deducted, from £4.75m to £4.85m in 2017-18.



The most expensive visit was to India, Malaysia, Brunei and Singapore with the Duchess of Cornwall, which cost the taxpayer £362,149. The couple flew on an RAF Voyager that is available only to the prime minister, foreign secretary and the royal household.

An aide said the Voyager was deemed more appropriate and cost effective than scheduled flights because of the complexity of the trip, and was also more appropriate for someone representing the Queen. “We are using the same aircraft that the prime minister or the foreign secretary would be using if making a similar visit,” he said.



Facebook Twitter Pinterest Prince Charles boards the royal train in 2010. Last year’s accounts showed he was the biggest user of the mode of transport, the most expensive form of royal travel. Photograph: WPA Pool/Getty Images

Prince Charles also emerged as the main user of the royal train, which, mile for mile, is the most expensive form of royal travel. Officials have long argued it is more comfortable and accessible for an elderly monarch. However, the Queen used it three times last year, while the prince used it seven, with each journey costing an average of £20,000. His overnight rail journey from London Victoria to Newport, south Wales, to carry out engagements cost £18,032, while a similar trip from London Victoria to Durham cost £21,361.



A spokesman said there were no plans to decommission the royal train. “It provides a secure form of travel, and particularly secure overnight accommodation, which therefore ensures that we are able to minimise the disruption to others when engagements are outside of London”.



Crown Estate profits up 4%

The Crown Estate’s annual results show it made profits of £329.4m in the year to 31 March, all of which flow into Treasury coffers. Like-for-like profits are up 4% from 2016-17, from its assets in England, Wales and Northern Ireland. The estate has lost annual profits of about £12m derived from Scotland, as those assets have been devolved to the Scottish government.



The total annual return on the estate’s £14.1bn portfolio was 11%, comfortably ahead of the property industry benchmark’s 8.2%, driven by its growing offshore wind portfolio and flagship retail lettings in central London to Microsoft, L’Occitane, H&M and Aspinal of London.

The estate derives most of its income from a vast property portfolio that includes London’s Regent Street and Windsor Great Park, and also manages most of the UK’s coastal waters. Its chief executive, Alison Nimmo, said offshore wind turbines installed on its sites can produce enough electricity to power 5m homes. UK waters are home to more than a third of all offshore wind turbines around the world, she said. Offshore windfarms are on course to deliver 10% of the UK’s electricity demand by 2020, after costs more than halved between 2014 and 2017.

Julia Kollewe