The value of the property owned by British Land went up by 12.1% last year, while the value of its office and residential space jumped by 18.8%. British Land said this was due to "the strength of the London market and our actions."

British Land's "Cheesegrater" building in the City — proper name the Leadenhall Building — smashed rental records in London last year, with space going for £90 ($142) per square foot. British Land said today the building is now 84% let.

Home and flat prices are also going nuts, too. British Land made £259 million ($409 million) selling just 22 apartments at its new Clarges development in Mayfair, which works out at almost £12 million ($18.95 million) per flat. The Clarges development also broke Mayfair sales records, selling at an average of £4,750 ($7,500) per square foot.

British Land put the crazy residential prices down to rich foreigners buying up luxury flats in London as an investment. The company said: "The UK remained the real estate investment market of choice for overseas capital in search of yield. London continued to be the principal beneficiary, with demand driving yields down in both the City and West End."

British Land doesn't expect the capital's property boom to end any time soon either, with big developments planned in Shoreditch and Surrey Quays.

Management said in today's results: "We continue to focus on our wider investment themes of London and the South East, targeting areas which will benefit from growth and regeneration and increasing our exposure to major transport interchanges."

British Land's underlying pre-tax profit in 2014 rose 5.4% to £313 million ($494.2 million).