Ralph Lauren has a fashion empire. And now he has a worthy palace. A $14 million renovation has turned the elegant Rheinlander mansion on Madison Avenue and 72nd Street into a four-story showcase of the designer's creations for men and women and for the home.

Since the store opened about two weeks ago, limousines have been lined up outside like at a society wedding and customers such as conductor/composer Quincy Jones, Warner Communications CEO Steve Ross and advertising executive Mary Wells Lawrence (who walked out of the shop the first day with five shopping bags) helped boost the first week's sales to $1 million. Even the designer admitted, sheepishly, "It's too crowded at the moment."

Lauren calls the project his "labor of love." Those seeing his clothes as part of a mix in department stores "don't really know what I do," he says. "They know I'm successful but they don't really know what I make. At stores they see only things store buyers buy that are mainly of mass appeal. In my shop they will see everything that is me." The vast range of items, from the familiar polo shirts to the exquisite quality shoes and bags, plus the couture-quality women's clothes and menswear and the completely decorated home settings under one roof, are a lesson in craft and craftsmanship.

And the shop, which has attracted admiration galore from New York and out-of-town merchants, is a lesson in contemporary display and merchandising. Mixing antiques and beautifully crafted new armoires and shelves, it gets an informal and almost cozy appearance from the warm woods and the generous use of old books and baskets as part of the display. Old suitcases tucked on top of shelves give the store a homey feeling.

Homey but no home for Lauren. "I wish I could live over the store, but there is no space. It's a letdown to go home."