The thirtysomething brothers behind the luxury property boom

For the Candy brothers, it seems, little can go wrong these days. The property developers for the super-rich have just renewed their lucrative partnership with the architect Richard Rogers to create another luxury estate of glittering apartments.

If you are a first-time buyer or a key worker in search of a London flat, you will probably not be knocking on the door of Candy and Candy's Knightsbridge headquarters, across the road from Harrods. But should you be an oil-rich sheikh, a Russian oligarch, or a celebrity such as Kylie Minogue or Gwyneth Paltrow, the brothers can ease you into the apartment of your dreams, for £20m or more.

The brothers, Nick, 34, and Christian, 32, are the latest entrants to the little club of ultra-successful siblings in business. Like the Barclay twins, they are in a line of business that invites attention, but are themselves quite media shy.

They divide their time between London and Monaco, taking a break sometimes on a yacht in the south of France, or on holiday together in Ibiza. Both are unmarried.

Defying those forecasters who say that land and house prices in London have hit their peak, the brothers paid £600m for Chelsea Barracks, where there is permission for 1,500 new homes, and have enlisted Lord Rogers of Riverside to design the project.

Lord Rogers also designed 86 luxury penthouses at One Hyde Park, opposite Harvey Nichols, in Knightsbridge, where there used to be a landmark 1950s office block called Bowater House. Before these penthouses went on the market, it was assumed that the upper price limit for any London home - however luxurious - was £2,000 per square foot. The Candy brothers made £4,000 per square foot their starting price.

The flats, which should be ready for habitation in 2009, have 24-hour room service, huge baths hewn from wood, marble work surfaces, floor to ceiling fridges, panic rooms, bulletproof windows, private lifts direct to each flat, as well as eye scanners, parking spaces for 115 vehicles below ground, and spectacular views over Hyde Park and The Serpentine.

Last month it was reported that Sheikh Hamad bin Jassim bin Jabr al-Thani, Foreign Minister of Qatar, had put his name down for one of the apartments, spending £100m. Two other apartments have also reputedly gone for similar amounts. This shattered the previous record price for a London flat, which was £27m, paid by a British financier for an apartment in Chelsea. Again, the vendors were the Candy brothers. The most expensive house ever marketed is said to be Updown Court, in Windlesham, Surrey, which went on sale two years ago for £70m.

The sheikh is not just a customer of the Candy brothers. Reputedly, it is his immense wealth, combined with money from a number of rich Qataris, that has bankrolled several of the Candy brothers' most expensive ventures.

The sons of an advertising creative and a drama school student, brought up in Surrey, Nick and Christian Candy bought their first flat in Earls Court in the mid-1990s, with £6,000 loaned to them by their grandmother. At that time, one brother was an investment banker, the other was in advertising. They did up the flat, laid a new carpet, sold it, and bought another. In 1999, they founded the property company Candy and Candy, which now has slick headquarters with banks of employees designing sample interiors.

As they progressed, they specialised more and more in dream homes for the ultra-rich. Apparently, they took their cue from Sir Henry Royce, who said: "Strive for perfection in everything you do. Take the best that exists and make it better. When it does not exist, design it."

In February, they applied to Westminster Council for planning permission to turn the Middlesex Hospital site in Mortimer Street into a luxury development consisting of 273 new homes and 33,000 square feet of office space, with a landscaped garden. The site was bought for £175m three years ago by a consortium led by Christian Candy. One third has been earmarked for affordable homes.

As well as choosing locations carefully, the brothers take minute care over the interior of every apartment, to ensure Candy and Candy remain a niche brand. Unlike older English homes, their properties have no narrow corridors or staircases. They believe in lateral space, and light.

One of the gadgets devised by their team is a 360-degree mirror. It looks like an ordinary full length mirror, but it is actually a life size video screen with a time delay. You can stand with your back to the mirror screen and then turn around, to observe whether your bum really is too big.

"The inside of a Candy and Candy apartment is a polycentric experience," Nick Candy told Vacation Homes magazine recently. "The smell of leather, the touch of softest cashmere and suede, shimmering silks, polished exotic wood floors and doors, carefully book-marked rare marbles and illuminating Venetian plaster to give a lustrous effect at night - it all creates the most sensuous experience you can have in a home."

Brothers in business

* SIR DAVID AND SIR FREDERICK BARCLAY

Twins, born in London in 1934. They entered the hotel business in the 1960s and expanded into newspaper publishing in the 1990s, bought Littlewoods in 2002, and the Telegraph Group in 2004. Their combined wealth is said to be £1.3 bn.

* DAVID AND SIMON REUBEN

Iraqi Jews, born in Bombay, their fortune originated from trading in metals in post-Communist Russia. Since 2000, they have specialised in the UK property market. Their fortune is said to exceed £4bn.

* MAURICE AND CHARLES SAATCHI

The Saatchi & Saatchi trade name shot to prominence when they designed the "Labour Isn't Working" poster that helped Margaret Thatcher to power in 1979. The sons of Iraqi Jews, brought to the UK as children, founded the agency in 1970 and made it the world's biggest, before they were forced out in 1995.