TEXTILE designer Jack Lenor Larsen was a hands-on creator from his youth. ''Even when I was 6 or 7,'' he said in a recent interview, ''I was trying to build every structure imaginable, from treehouses to log cabins to underground burrows.''
Mr. Larsen is still an ambitious builder. From his start 40 years ago weaving fabrics by hand, he has built an empire that weaves together art and industry. ''In the world of design, he's tops,'' says Mildred Constantine, former curator of design at the Museum of Modern Art in New York.
As head of Jack Lenor Larsen Inc., the designer employs hundreds of thousands of artisans in more than 30 countries. His employees spin yarn and weave fabric for upholstery, carpets, and wall coverings sold in 37 showrooms around the world. He has created textiles for projects by celebrated architects like Louis Kahn, Eero Saarinen, and I.M. Pei, and his works are in the permanent collections of New York's Museum of Modern Art and the Victoria and Albert Museum in London.
Larsen is now perfecting his ultimate design, Long House, a 16-acre estate in Long Island, New York's artsy East Hampton. ''It's about pushing boundaries,'' Larsen says. ''I try to go beyond where I've been.'' He intends to leave the estate and gardens as a public bequest, a one-man museum of tasteful living. With a central axis of 180 feet, the 12,000-square-foot Long House is literally long on space. It's also about Larsen's long-range goal: educating the public in how design and craft enrich daily life.
''We learn best through a three-dimensional experience,'' Larsen explains. ''Whether it's a garden or a living space, we learn faster and deeper from the experience of being in the space.''
Long House is modeled on Ise Temple, the 7th-century Shinto shrine where Japanese emperors are crowned.
Larsen's four-year-old home is a similar shrine to crafts, filled with his collections of tribal artifacts and contemporary art-in-craft media like textiles, ceramics, baskets, and classic modern furniture. He acquires these objects by ''gut reaction,'' he says, adding, ''The objects must have an interesting play to them between technique and color. And they should have something that is appealing, like certain lines of poetry and music, and a twist that goes beyond the norm.''
Although Long House is huge in scale, rising to 37-foot-high peaked skylights, it's also intimate. Eighteen different areas function as showcases of design, where every surface is animated with color, texture, and pattern. ''We live in a world of hard, monotonous surfaces, like white drywall, glass, and appliances that have no tactile or material richness,'' Larsen says. ''Fabrics create a sense of the personality of people using the spaces. They reinforce our individuality.''
Larsen, who is president emeritus of the American Craft Council, further explains, ''We rely so much today on being rational. Long House allows us to experience sensual pleasure, through immersion, in a more holistic way and with more passion.''
In designing textiles, his primary consideration is respect for craft quality. Unlike machine-made objects, handcrafts radiate the spirit of the maker and the organic vigor of materials. A warp-printed silk from Korea sparkles with the broken colors of nature, a quality, Larsen says, ''that is always outdoors and so seldom indoors.''
Traditional skills inspired one of his most successful designs, a tie-dyed silk upholstery called ''Laotian ikat.'' One Christmas Larsen realized that torn paper produced the feathery edge typical of ikat. Ripping apart Christmas cards with abandon, he created a collage that Thai weavers duplicated. The Saudi Arabian court immediately ordered 700 yards; the design became a best-seller.
''Distinguished aging'' of crafts is another aim for Larsen. While most manufactured goods peak in attractiveness when new, fabrics ''should mellow, like weathered cedar shingles,'' he says, ''and achieve more charm with time and use.''
For this classic timelessness, his designs, like his collections of craft objects, are ''generally low-key. They don't wag their tails,'' Larsen says. Like ''Granite,'' a fabric of natural, undyed yarns the Kennedys selected for the White House, the designs soothe with stippled light and shadow.
Larsen designs can also invigorate. Designing fabrics for the first 747 jets, he gave Braniff an exotic lift by drenching yarn in red- orange dye, festive as a tropical sunset.
''I'm moderate in almost nothing, and contentment has never appealed to me,'' says this weaver-turned-entrepreneur who improvises his life and art with unbridled ardor.
With the practiced eye of one who derives inspiration from nature, he observes squirrels scrambling to the brink of white oak branches to seize acorns.
''My philosophy is that we should remain out at the fringe as long as possible,'' Larsen says. ''At some point, I will be looking for the safe crotch of the tree where the wind doesn't blow,'' he adds. ''But not soon.''
For the visitor, a tour of Long House provides a virtual survey of American craft, design, and gardening.
''I want people who come to think of art in terms of living,'' Larsen says, ''not just looking.''