The royal property portfolio: with 775 rooms, Buckingham Palace is estimated to be worth £2.2 billion

Buckingham Palace is worth in excess of £2.2 billion - based on its size alone - according to estimates by Foxtons estate agents.

The Queen's London residence measures a colossal 828,821 sq ft and has 775 rooms over set over five floors.

There is also a doctor's surgery, a swimming pool and 40 acres of manicured gardens in this prime central London location alongside St James and Mayfair, where property values are estimated at £2,500 to £3,000 per sq ft.

The Royal Collection Trust is responsible for the care of the official residences of Her Majesty, including Buckingham Palace and Windsor Castle, as well as Clarence House, the official London residence of the Prince of Wales.

The full extent of the Queen's assets are not known, as many details of her income are not released publicly.

Her personal property portfolio includes Sandringham House in Norfolk and Balmoral Castle in Aberdeenshire - an impressive 70,000 acres of land in total - that was passed down from Queen Victoria.

Other members of the Royal family also live on these sprawling estates, including the Duke and Duchess of Cambridge. The Queen "gifted" William and Kate Anmer Hall, a 10-bedroom Georgian home on the Sandringham estate, which has a private pool and tennis court.

The Crown Estate, which owns property on behalf of the Queen, has one of the largest property portfolios in the UK. According to BBC reports, the holdings are valued at about £11.5 billion.

The estate is run as an independent commercial property business, which includes most of Regent Street, and the Queen receives 15 per cent of its profits.