Buckingham Palace is to have its first major refit since the 1950s, in the hope of avoiding potentially "catastrophic scenarios".
But what will the refit of one of Britain's most famous residences involve? Here are a few facts about the 10-year plan:
The most urgent work is scheduled to take place first, in a two-year period as of April. The focus will be on the basement, and replacing electrical and heating generation and distribution services.
Some of the electrical cables in the palace are more than 60 years old and need to be replaced because of the "significant risk of electric shock and fire".
The 30-year-old boilers will also have to go and it is hoped new, more efficient ones will lower the palace's carbon footprint by around a fifth.
While the key works are taking place during the first two years, design plans will also be drawn up and finalised for the rest of the palace.
By April 2019 officials hope to be starting work on the east wing - the front of the palace where thousands of visitors gather every day - working clockwise, one wing at a time.
Work on the west wing and State Apartments will be done gradually throughout the 10 years, so that the palace can stay open to visitors.
Up to 125 staff could have to be moved to temporary accommodation in the garden, but the royal family will remain in residence in the palace.
Among the fixtures and fittings to be replaced will be 100 miles of electrical cabling, 5,000 light fittings, 2,500 radiators and 20 miles of skirting board.
Officials said there is "not an anticipation" to erect scaffold fully around the building, adding that much of the work will be "quite hidden" from the public. Major events - and key tourist draws - including the Changing Of The Guard and Trooping The Colour will be unaffected, they added.