Roman Abramovich already has one of the priciest homes in London, but frankly it's just not good enough for the billionaire Oligarch. He's splashing the cash on a massive revamp, which is expected to take the value to an astonishing £140 million.
The property is on so-called Billionaire's Row, Kensington Palace Gardens - which runs alongside Kensington Gardens, a stone's throw away from the Palace. His famous billionaire neighbours include steel magnate Lakshmi Mittal and Tamara Ecclestone, daughter of racing boss Bernie.
The mansion set him back a reported £90 million in 2009, which should have ensured him reasonable accommodation, but apparently not. According to The Sun, Roman Abramovich's architects describe part of the property as 'miserable' in their planning application, so to cheer things up a bit he will fork out £28 million on a massive underground extension.
The current pool is described in the application as 'miserable', so it will be ripped out and replaced with staff quarters. In case you were worrying that Abramovich might miss his daily dip, don't panic, because the plans also include a massive underground leisure complex under the garden.
The Mirror reported that it will draw: "on the language of Victorian subterranean construction across London". It added that the underground pool would be an "architecturally significant addition to the original building." The council will announce its decision whether or not to allow the building later this month.
Abramovich is not the first famous face to have embraced the idea of underground living. On the same road, neighbours Lakshmi Mittal and Tamara Eccleston have both taken the same approach.
David Cameron had an underground extension built before moving to Downing Street. Nigella Lawson had one built in the Chelsea home she shared with Charles Saatchi. Andrew Lloyd Webber is also a veteran of underground building, as are Sarah Beeny, Jemima Khan and Nicole Kidman.
However, basement extensions are not simple to get past the neighbours or the council - even if you are a celebrity. Back in April this year, Robbie Williams ditched plans for a two-storey basement extension to his home in Holland Park after complaints from neighbours - including Led Zeppelin star Jimmy Page.
Abramovich already has form for being persuasive on this subject: in 2013 he was given permission for a separate basement extension for a home in Chelsea. However, he will have to wait and see whether he can strike gold for a second time.