Karl Lagerfeld is about to engage in the ultimate act of spring cleaning.

On Thursday, the fashion-forward designer will unload two housefuls of fabulous, lovingly collected furnishings at auction. In a move as radical as any catwalk fashions, he is sweeping art deco out of his life -- or at least out of his homes in Biarritz and Monaco.

Lagerfeld could reap $3 million to $4 million from the sale of elegantly simple tables, chairs, lamps, ceramics, even a mantelpiece, all of which will be offered by Sotheby's in Paris. Of the 240 pieces being offered, many were signed by some of the most sought-after names in 1920s and 1930s design. There are more than 50 pieces by Jean-Michel Frank, including chiseled X-shaped side tables and a rare quartz table lamp. Other highlights include a sturdy oak and black-lacquer console table by Eileen Gray; a chrome ink stand and a mirror by Jacques-Emile Ruhlmann, and a rare parchment architect's portfolio by Pierre Legrain, who was known for African-inspired cubist furniture. Overall, the collection reflects the beginnings of modernism in a soothing palette of whites, browns, grays and black.

Collectors will note that the sale comes just as the prestigious Victoria and Albert Museum in London has opened its landmark art deco exhibition, with the stated intention of upgrading the period's reputation from merely glamorous to seriously artistic.

An interview in the French magazine Point de Vue suggests that recouping an investment was not Lagerfeld's motivation.

"Possessions were beginning to suffocate me," he said. "I have decided to possess less."

There was another reason. "I create dresses of today, and therefore I must live in a decor of today," he said.

Lagerfeld has reportedly moved on to the cutting edge, collecting the works of Ronan and Erwan Bouroullec, two brothers from Brittany who are France's newest design stars. He also is said to be a fan of London-based industrial designer Marc Newson.

"For the moment, objects don't attract me," he told the interviewer.

He made clear that he didn't want to be tied to the past, for fear it would hinder his ability to design for the present. He was determined to wipe the slate -- and the houses -- clean.

It is not the first time. For two decades, Lagerfeld has been acquiring and casting off decorative arts -- tables, sofas, chairs, lamps, even mantelpieces -- the way most people refresh wardrobes with seasonal attire. He kept his Paris apartment fixed in the 18th century until 2000. But he seems to take on a new decor as easily as some people grab the latest color in T-shirts and scarves.

In the 1980s, Lagerfeld was among the first to adopt the gaudy, wildly inventive furniture from the Memphis group in Italy, which he installed throughout his Monaco apartment.

Memphis, which was introduced to the public in 1981, offered a new, postmodern aesthetic. There were patterned plastic laminates instead of marble, and bold pinks and greens in place of pristine modernist white. The movement wreaked delightful anarchy on the staid world of home design. It was bold and influential, and followers of fashion will remember that equally bold patterns returned to the fashion runways within a few cycles.

Lagerfeld gave his apartment over to the decorative chaos, which included a conversation pit designed like a boxing ring by Masanori Umeda. Then, in 1991, three years after Memphis disbanded, Lagerfeld asked Sotheby's to sell all of his 133 pieces, including one of everything from the original 1981 collection. The sale brought about $280,000. The top seller, at $29,000, was a dressing table by Michael Graves, which stood seven feet tall and was surrounded by light bulbs.

Three years ago, a sale by Christie's emptied Lagerfeld's Paris house of its Marie Antoinette-era furnishings. The treasures collected over 20 years included furniture by Pierre Boulle, Jean Henri Riesener, Jean-Francois Oeben and Martin Carlin. They sold in two days for $21.7 million, the second highest amount for such works in the auctioneer's record book. The French government bought four Gobelins tapestries and returned them to their original chateau.

Those sales, which began merely as a change of decor, wound up sparking a realization. For Lagerfeld, the creation of the ambiance was more important than living in it. He was an assembler rather than a keeper. "After a while, I need change," he said. "It's a question of survival. . . . One has to free oneself to be able to conquer something else."

For those who can't afford to bid on a $200,000 dressing table with oval mirror by Legrain, which is one of the highlights of the sale, there is still a lesson. Lagerfeld has divested twice before. By his example, the style-maker may be giving the rest of us permission to set ourselves free.

"It's always more easy to stay in one's cocoon than to break out of it and venture into the unknown," he acknowledged. But, he cautioned, "It's better to leave things before they leave you."

Go to www.sothebys.com for a slide show of the Lagerfeld collection. For a reprise of Memphis, visit www.designaddict.com.

Among the art deco furnishings the fashion designer is putting up for auction are oak side tables, walnut armchairs and a plaster two-arm lamp, bottom, all by Jean-Michel Frank.A $200,000 dressing table by Pierre Legrain is a highlight of the sale of 240 pieces from Karl Lagerfeld's homes in Biarritz and Monaco.