LOUISE BOURGEOIS made art almost up to the day she died on May 31st 2010. She was in her 99th year. Bourgeois had her first major retrospective at the Museum of Modern Art in New York in 1982. She was 71 at the time. Some might have taken this as a sign that it was time to retire. But Bourgeois went on to produce her most ambitious works—large-scale spider sculptures and dreamlike installations that she called “cells”—when she was in her mid-80s. She had trouble with mobility in her old age, but she enjoyed a clear head. Her steely will was legendary.

"Louise definitely had a psychological need to work," explains Jerry Gorovoy, her chief assistant of 30 years. "She needed to record how she was feeling. She worked to understand the sources of her anxiety, to calm herself, to repair or alleviate guilt." A well-groomed hippie with an art-school degree, Mr Gorovoy is in Bourgeois's home on West 20th Street in Chelsea, New York. "The reality that she is not here," he says, "it's still very surreal to me." An appraiser strolls into the room, notebook in hand. The estate is in the process of being divided between the family and the foundation, which has been bequeathed this house as well as the one next door. Nothing has been decided but the townhouses will probably become an archive and research centre for Bourgeois scholars.

Bourgeois's home was utterly utilitarian. When the artist and her husband, Robert Goldwater, an art historian, moved into the tall, narrow brownstone in 1962, the house had a living room on the ground floor at the back. After Goldwater died in 1973, this room mutated into a cluttered, grubby office-studio. Ten years ago, the artist stopped going regularly to her atelier in Brooklyn in favour of spending most of her time in this room, sitting at a square wooden table with her back to the kitchen. To the left of the table stands a mess of paints, brushes, pens and pencils beneath an oversized bulletin-board smothered in clippings and photographs. To the right, a wall of books and filing cabinets rises up behind a haphazard collection of flea-market chairs. In her final years, Bourgeois slept a few feet away in an ascetic room with a fluorescent light on the ceiling and important phone numbers written four-inches high in black marker on the wall. The only traces of luxury are the gold hoop earrings that appear in so many portraits of the artist, which are strewn on the mantle as if just taken off for the night. "The whole house was a studio," explains Mr Gorovoy. "Louise was not into domesticity at all."

Late in life, Bourgeois found an artistic project for which she had a pathological drive. The artist had a phobia about throwing things out, so she had accumulated chests full of clothes—hers, her husband's and her sons' (she had three, two survive)—as well as old tablecloths and other linens. She began incorporating whole garments into works. Then, within a year, she started cutting the clothes up, transforming them into sculptures and the collages she called "fabric drawings". "Louise always said that she started with an emotion, not a concept," explains Mr Gorovoy. "Clothes have a memory and a history. She wanted to process them all. She never mentioned the word 'death', but she must have felt the clock was ticking."

In the basement of the house, at a table beside a drill press and a 60-year old print-making machine, Mercedes Katz is finishing the hand-stitching on an editioned Bourgeois piece that depicts a clock. Ms Katz, a highly skilled seamstress from Argentina who once worked for Oscar de la Renta, answered an ad in Women's Wear Daily in October 1999. Thereafter, she was Bourgeois's principal and often only assistant on the fabric pieces, working six days a week from 11am to 7pm, then more recently from 10am to 5pm.

Working at home with a seamstress must have felt natural and satisfying to Bourgeois. The artist's father had been in the tapestry-repair business, so Bourgeois grew up surrounded by teams of women sewing and weaving under her mother's direction. Throughout her life, Bourgeois avoided assistants who were artists, preferring to work with adept craftspeople who wouldn't interfere with her ideas.

Bourgeois's productivity might have been enhanced by her selective social world. Somewhat agoraphobic, Bourgeois stopped going to her own openings. "She'd had enough of the New York art world," explains Mr Gorovoy. "Louise was interested in the piece she was working on now. She was very much about having a certain concentration, a certain silence." But on Sundays, Bourgeois would engage with outsiders by hosting salons attended by people who were invariably much younger than her. "The salons were like group therapy," explains Mr Gorovoy. "Poets, musicians, curators would end up fighting, crying. It was pot-luck because you didn't know who was coming."

Of all the factors behind the longevity of Bourgeois's creativity, perhaps the most determining was the intelligent loyalty of Mr Gorovoy. Bourgeois's biographer, Robert Storr (whose book, "Intimate Geometries", will be published next year), points to the importance of Mr Gorovoy's "multi-faceted presence" in the artist's "motivation to continue". Bourgeois was in psychoanalysis between 1951 and 1966, and continued to see her therapist periodically until 1980, the year Mr Gorovoy started working for her. "When you are at the bottom of a well," Bourgeois once said, "you look around and you say, who is going to get me out? In this case, Jerry comes and presents a rope."

"We made a bargain," says Mr Gorovoy. "Louise would make the work and I would do everything else." When Mr Gorovoy was a fledgling curator, before he worked for Bourgeois, he put her art in a group show, which caught the attention of the MoMA curator who went on to oversee her retrospective. Once in the artist's employ, Mr Gorovoy coordinated with the foundries, dealers, curators and critics. "My mission was to get people to see her work because I thought it was really important," he explains. This division of labour would occasionally lead to arguments. "We had our fights. She blamed me for putting pressure on her. She'd say, 'You want the show, Jerry. I don't want it. I'll do it for you but I don't need it!'" Bourgeois enjoyed the exposure, but she didn't like the distraction or the way that exhibitions took Mr Gorovoy away from her side.

Mr Gorovoy's life's work has been devoted to Bourgeois's life's work. Why? "One day became the next day and the next week," he says, almost under his breath. "I never stopped learning from Louise. I never figured out all the pieces of the puzzle. She still remains a mystery to me." He takes a long, deep sigh and adds, "Louise was a rare human being. An amazing, complicated person."

Louise Bourgeois's "The Fabric Works"
will be the inaugural show at Hauser & Wirth's new space in Savile Row, London, on October 14th.

Images of artworks: © Louise Bourgeois Trust, Courtesy Hauser & Wirth and Cheim & Reid. All photos by Christopher Burke except "Cell (Clothes)", which was shot by Attilio Maranzano.