Martin Summers remains the capital's favourite art dealer to the stars and the super-rich, with clients including the likes of Sir Elton John, Rod Stewart and Art Garfunkel. Guests at his 1977 wedding to his second wife, Nona, included Stavros Niarchos, the shipping tycoon, Princess Caroline of Monaco and Christina Onassis.

The 69-year-old jet-setter, who is now married to his third wife, Anne, is selling his gallery, a converted studio house next door to his own home in Glebe Place, Chelsea. He scoffs at any suggestion that he is slowing down, however. “I simply want to be free, so that I can travel even more,” he says. “I still intend dealing in art but I don't want to be tied to organising exhibitions in London any more.”

Glebe Place is the site of a famous hoax devised by the actor Rupert Everett. “He hoodwinked me and everyone else in the street,” Summers recalls. The story goes that Summers was holding a fairly riotous party, with a guest list that included Jack Nicholson, when Everett phoned him, pretending to be from the Water Board. He ordered Summers to turn on all the taps, flush the lavatories and to get all his neighbours to do the same because “there's a build-up of pressure under the house with a risk of explosion”.

Summers, not at his sharpest, did as he was told. Everett went a step further: he persuaded him to evacuate the house and to get his neighbours to do likewise. These included members of The Gateways, a lesbian club on the corner. Soon, a broad social mix was milling around Glebe Place, waiting to see their homes blown to smithereens- until the police arrived and sent everyone home. The pay-off is that Jack Nicholson, the great womaniser, went back to the wrong place and ended up dancing the night away with two lesbians at The Gateways.

It should be relatively straightforward for a new owner to convert the gallery, which dates from 1891 and is for sale for £3.75 million, back into a house. It was lived in by a family with two children before Summers, pictured, bought it in 2002. A ground-floor room now used as a store will easily revert to being a kitchen as all the plumbing is intact. The other room on this floor would make a fine bedroom as there is a modern bathroom across the hallway. Upstairs, the question of how to make best use of the gallery itself, with its enormously high ceilings - 26ft in places - is the kind of problem that most buyers welcome. One solution would be an open-plan living space with perhaps a mini-library in the corner that is now used for office work. The light from the huge skylights and the six windows would flood into a cavernous, loft-style room.

From the main gallery, with its oak floor, you climb a staircase to the mezzanine level. This could make an open master-bedroom, or the whole area could be made separate from the space downstairs. There is also another bathroom, a dressing room and lots of cupboard space on this floor. You would certainly feel safe in this house, as the security system is extremely high-tech.However, half the attraction of Glebe Place lies outside: the buyer would become part of one of Chelsea's most exclusive enclaves. Just off Kings Road, this is the stamping ground of the seriously wealthy, with just a dash of bohemia thrown in. As a mere taster, the Niarchos family have a house here, David Bowie used to live near by, the advertising guru Sir Frank Lowe lives just along the street, as does Peter Simon, the chairman of Monsoon.

Glebe Place has seen some of the Summers' most uproarious parties. On his 60th birthday, for example, he planted an enormous mobile kitchen serving Chinese food just outside and five of his neighbours opened up their homes to help to entertain the hordes of guests. For his 64th he had a Beatles theme: George Harrison's son, Dhani, sang When I'm Sixty-Four with the rock star Seal. This year, for his 70th, he is breaking with tradition by holding his birthday away from “The Place”. Instead, he has invited 100 friends to his home in Garzon, Uruguay, for a three-day jamboree.

As well as enjoying the life of a dedicated playboy, Summers has clinched some huge art deals over the years. In the 1980s, at his previous gallery, The Lefevre, a Japanese businessman bought a Van Gogh for $82 million: he returned the following day and spent $75 million on a Renoir. So will Summers miss doing business with the world's major players?

“Of course, I will,” he says. “People who are rich enough to buy art from me have either inherited wealth, in which case they have taste, or they have talent, or they are gangsters. Whichever they are, they are interesting. I'll miss them. But I'll still be around. And I'll be free.”

Fast facts

The average price of a home in Kensington & Chelsea is £1,898,286. The national average is £216,075 (Land Registry).

Five years ago the average K&C price was £645,923 and the national average was £155,284; ten years ago it was £369,505 and the national average £80,108.

Martin Summers' gallery is for sale through Aylesford: 020-7351 2383, aylesford.com

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