The work was ordered after a safety audit found the building, and the precious art and furniture within it, was at serious risk of fire or water damage.

The royals are understandably worried – a 1992 fire at Windsor Castle caused £36 million ($60 million) of damage, devastating several beautiful old rooms – including the Queen's private chapel – and ruining a valuable painting, chandeliers and carpet.

It was part of the Queen's infamous "annus horribilis".

But for the sake of safety, the Queen will have to put up with a lot of banging – she has no plans to move out while the renovators are in.

The 10-year project, which begins in April 2017, will replace miles of ageing power cables, lead pipes, electrical wiring and boilers, many for the first time in 60 years.

It will start with the most urgent work, then include improvements on public access and visitor facilities.

The building will also be made much more energy efficient, with improved insulation and heating lowering the palace's carbon footprint by an estimated 40 per cent.

Master of the Queen's Household, Tony Johnstone-Burt, said the building program would extend the palace's working life by 50 years.

"On completion of the work, we'll have a palace fit for purpose until 2067," he said.

"The program addresses parts of the structure you can't see from the outside: the plumbing, electrics and other essential building services which have gone six decades without a comprehensive upgrade.

"We are convinced that by making this investment in Buckingham Palace now, we can avert a much more costly and potentially catastrophic building failure in the years to come.

"We are also confident that our chosen option – the 10-year phased refit – offers the best value for money."

The money will come from a temporary increase in the 'Sovereign Grant'.

Income from the Crown's estate goes to the government, and a fraction (15 per cent) known as the Sovereign Grant is returned to the royal family to pay for their travel and real estate upkeep. That fraction will rise to 25 per cent to pay for the Buckingham Palace work.

The Royal Household's Director of Property, Paul Duffree, said recent surveys had revealed "a number of high-risk areas which we need to address as a priority".

The work will be done by experienced professionals and those just starting out in their careers – apprentices and graduates. They also plan to source over 50 per cent of the materials from within the UK.

The Queen will stay in residence throughout (though she usually spends some of the year at Windsor and Balmoral anyway). Major events including annual garden parties, investitures, Trooping the Colour, state visits, Changing of the Guard and the Buckingham Palace Summer Opening will all continue as normal.