Prince Harry and Meghan spent £2.4 million of adult taxpayers' money in order to do up their home.
The Duke and Duchess of Sussex live in Frogmore Cottage in Windsor and it was turned into a single property for them from five separate homes.
The couple moved from Kensington Palace in April before the birth of their son Archie.
The renovation to the building where they now live was paid for by the Sovereign Grant, which is mostly made up of tax money that adults have to pay to the UK government.
The Sovereign Grant is money paid from the government to the Royal Family to cover the cost of official duties and looking after royal palaces.
The Queen's Sovereign Grant from the Treasury was £82 million in 2018-19, with £33 million set aside for buildings, including major work on Buckingham Palace. This is equivalent to £1.24 per person in the UK.
It's not just taxes which go into the Treasury though. The Crown Estate provided £343.5 million in 2018-19.
The Crown Estate is an independent property company, which belongs to the monarch throughout his or her reign. It owns residential houses, commercial offices, shops, business and retail parks across the UK.
Properties owned by the Crown Estate include Royal Ascot racecourse, a retail park in Slough and several wind farms.
Although it belongs to the monarch, they cannot sell any of the properties and all profits must go into the Treasury.
The Royal Family's Sovereign Grant is based on 15% of the net surplus - that is, the amount left after certain expenses are taken out - of the Crown Estate.
The 2020-21 grant is expected to be £85.9 million.
Supporters of the Royal Family say the monarchy brings in a lot of money through tourism and that having the Royal Family as ambassadors also boosts trade.
The tourist board of Great Britain, VisitBritain, says tourism to royal residences like Buckingham Palace and Windsor Castle brings millions of visitors - and therefore money.
Some people say tourism from the monarchy brings in about £550 million. But there is no way to know exactly how much the Royal Family influences the number of people who choose to visit the UK.