In 2012, John Caudwell spent S$152 million to purchase the property. He spent S$113 refurbishing it. Today, it’s worth S$437 million

Mayfair is one of London’s priciest neighbourhoods. For decades, it’s been an ultra-exclusive enclave of wealthy Arab oil tycoons and celebrity-laden nightclubs. So it comes as no big shock that what is quite likely Britain’s most expensive home is located in the posh neighbourhood. What is surprising, though, is that the owner of the property is John Caudwell, an Englishman with working-class roots who made his fortune through the mobile phone company Phones 4U, which he sold for S$2.63 billion in 2006.

Known as Mayfair house, Caudwell’s roughly 3,994-sqm mansion was purchased in 2012 for about S$152 million. After a few years of throwing lavish parties, Caudwell recently embarked on an epic-scale renovation that reportedly ran him an astonishing S$113 million.

The construction project reportedly employed 300 workers and is the subject of a documentary, Britain’s Most Expensive Home: Building For a Billionaire. And it’s a far cry from the public housing that Caudwell grew up.

The property was purchased from a Channel Islands trust that linked to Jefri Bolkiah, the unfathomably rich and famously profligate Prince of Brunei. From the exterior, it looks similar to the many Middle Eastern banks and embassies that surround it. Inside, however, it’s a theme park of opulence.

Where numbers are concerned, the house is spread across eight floors, three of which are subterranean. You’ll find 15 bedrooms, a ballroom that can host 120 people, and get this, a 41-cm deep ‘river’ populated with African cichlid.

But get this – Caudwell doesn’t intend to use the property as his main residence, saying that he doesn’t “need a house anything like that size”. Instead, he hopes to host charity events for Caudwell Children, a 20-year-old charity he founded dedicated to helping children with disabilities and their families.

Unlike its muted exterior, which mostly blends into its surroundings, nothing about the home’s interior is understated. Given Caudwell’s taste in sparkling, Elton John-like jackets (which are displayed on mannequins in the home), it’s hardly surprising that there’s a more than just a hint of Liberace or Louis XIV about the place. The extensive renovations of the mansion include a ‘volcano’ wall, a swimming pool and staircases of solid white marble that connect to each of the eight floors. There’s also an Art Deco-inspired, lattice-fronted elevator, a cocktail lounge with low-lit velvet booths and a stage for live music plus an adjoining billiards room with a rose-covered ceiling.

Today, the property has a value of around S$437 million. “It really has been a labour of love,” Cauldwell said. “I was involved in absolutely every aspect of it.”

But how does the proud philanthropist justify spending such an ostentatious amount of money on a home?

“The house itself is a profitable venture,” Cauldwell said. “Far from taking away my ability to give to charity, it increases it because it has increased my wealth significantly. As 70 per cent of that is going to charity… it swells my ability to give during and after my lifetime.”