Officials say the palace needs an estimated £150 million of renovation and upgrades, including replacing old plumbing and wiring and removing asbestos. Having her move out during the work is one option being considered.

The Queen has several other residences but spends about a third of her time in the London palace, which was first used by her ancestor Queen Victoria. It is the site of summer garden parties and scores of ceremonial events each year.

Keeper of the Privy Purse Alan Reid said maintenance on aging royal buildings, “and in particular Buckingham Palace, will present a significant financial challenge” in the next few years.

Annual accounts published Wednesday showed that the monarchy costs taxpayers £35.7m in the year to March 31, the equivalent of 56 pence per person. That was unchanged from the year before.

Almost half the money, £18.7m, was spent on payroll costs, while property maintenance cost £11.7m and £5.1m was spent on official travel. The most expensive trip was an eight-day visit to Colombia and Mexico by Prince Charles and his wife Camilla, which cost almost £450,000.