Piping, electrical wiring and boilers will be replaced at Buckingham Palace
Funding for the British royal family will increase over the next 10 years to fund an urgent multimillion-pound renovation of Buckingham Palace in London.
A major refit costing stg£369m (€429.2m) is needed to "future-proof" the royal residence, officials said.
The UK government has agreed to pay Queen Elizabeth II more money - an increase of 66% in her annual sovereign grant - to cover the costs.
A statement from the palace said: "The 10-year phased refit will address the essential building services on which the palace depends.
"Miles of ageing cables, lead piping, electrical wiring and boilers will be replaced, many for the first time in 60 years.
"An independent specialist report concluded that without urgent work there is a risk of serious damage to the palace and the precious Royal Collection items it houses from, amongst other scenarios, fire and water damage."
Work to improve the palace will see 100 miles of electrical cabling being replaced, along with 6,500 electrical sockets, 5,000 light fittings, 330 fuse boxes and 2,500 radiators.
Some 30,000 square metres of floorboards - the equivalent of 3.5 football pitches - will be taken up.
The work will be funded by a temporary 10-year uplift in a sovereign grant, from 15% to 25%.
The grant is the allowance provided by the British government every year to fund Queen Elizabeth II in her official duties.
The money comes through the crown estate - a portfolio of land and buildings which belong to the monarchy but cannot be sold by them, and the profits go to the UK Treasury.
Queen Elizabeth II was previously given back 15% of those profits but under the new agreement this will increase to 25%.
Last year, that amounted to stg£40.1m (€46.7m), or 62p (72c) for every person in the UK.
The change in arrangements follows a review by the three royal trustees: the British prime minister, the chancellor and the keeper of the privy purse.
It had been proposed that the Queen may have to move out of Buckingham Palace while work takes place, but she will now stay for the duration.
Major events such as garden parties, state visits, investitures and changing the guard will not be affected.