The average billionaire is married, is worth £1.79bn, and would never spend less than £10m on a property – unless it was for the staff, according to research published on Sunday.
Of these, it said 60% were self-made billionaires, 20% had inherited wealth and the rest had a combination of part-inherited, part-made fortunes.
Alongside football clubs and fine art, property in London was found to be high on the list of must-haves for those with many millions in the bank: the research found that 67 billionaires were living in the city, making it the most popular of western Europe's capitals with the ultra-wealthy, ahead of Paris with 25 and Geneva with 18.
The typical billionaire holds £50m or more in real estate and has four homes. A property portfolio would typically include a £22.3m mansion in London; an £18.6m holiday home on the French Riviera and a £12.1m estate in Tuscany, alongside another luxury pad, perhaps somewhere more far-flung .
The researchers claimed a billionaire would "never spend less than £10m on a London property (unless it is for a servant)". This property might be in Chelsea, but the neighbourhood is not favoured by billionaires themselves – instead they prefer a mansion in the "platinum triangle" formed by Mayfair, Knightsbridge and Belgravia.
With an average of 2.1 children each, billionaires were found to favour family homes – the bigger the better with six bedrooms as standard, and to rank state-of-the-art security above lifestyle facilities. Features like iris-recognition technology, his and hers panic rooms and bullet-proof doors are not unusual now in luxury developments in the capital.
Gary Hersham of Beauchamp Estates said: "We advise UHNWIs [ultra-high net-worth individual] buying homes in London and around the Mediterranean to set aside budgets of typically £50m to acquire the right properties.
"Most UHNWIs buying in western Europe see having an ultra-prime home in prime central London and on the French Riviera as 'must have" badges'."
The research found that the world's wealthiest individuals hold an average of 42% of their wealth (£750m) in private holdings; 35% (£626m) in publicly-held companies; 18% (£322m) in cash; 3% (£54m) in residential real estate and 2% (£35m) in luxury assets such as artwork, yachts and private jet travel.
guardian.co.uk © Guardian News & Media Limited 2010