Lloyd Herman, who proposed the Smithsonian's Renwick Gallery as a showplace for American contemporary crafts, has resigned after serving as director for all the museum's 15 years, his staff was informed yesterday.

"The Renwick no longer has the budget to mount the kind of major craft exhibitions we have in the past," said Herman, by way of explanation. He said the Smithsonian's institution-wide 4.3 percent budget cut has forced the National Museum of American Art (of which the Renwick is a department) to severely cut back its exhibits.

Charles Eldredge, head of the Museum of American Art, and Robert McC. Adams, Smithsonian secretary, are "emphasizing building and researching the collections. However, the Renwick has been known for exhibitions and public programs," Herman said.

For some time, the Smithsonian has considered restricting the Renwick Gallery at 17th Street and Pennsylvania Avenue NW to displaying the diverse offerings of the Smithsonian Institution's Traveling Exhibition Service. Tom Freudenheim, the Smithsonian's assistant secretary for museums, is known to be replanning the future not only of the Renwick but also of the old Arts and Industries building, next door to the Smithsonian Castle.

The Renwick was built as the Corcoran Gallery by W.W. Corcoran in 1859, just before the Civil War. It was then used as a hospital and a warehouse. Later it was the U.S. Court of Claims.

It was officially given to the Smithsonian in the late 1960s, originally to display shows from other countries, particularly in conjunction with state visits. Blair House, the president's guest house, is just next door, and currently undergoing renovation.

The late Joshua Taylor, at the time director of what became the Museum of American Art, hired Herman in 1971 to give the building a reason for being and to oversee the final restoration of the Renwick by Hugh Newell Jacobsen (interior) and J.C. Warnecke (exterior).

The Renwick Gallery opened in January 1972, in time to promote the late 20th-century revival of American crafts. Since then, its 100 exhibitions have been important in encouraging the recognition of contemporary crafts here and abroad. Among the more important were a retrospective of the designs of Raymond Loewy, when it was touch-and-go if the Avanti car would make it up the Renwick's grand steps; the Craft Multiples show where Herman, complete with bow tie, posed in the wooden bathtub; the wooden-works exhibit that influenced at least three craftsmen who become well-known woodworkers; the retrospective exhibit of Anni Albers' textiles; and the current exhibition on the Johnson Wax buildings of Frank Lloyd Wright.

Herman, who lectures and writes on crafts and judges competitions all over the world, says he also has plans for a television series, exhibits and books.

No successor has yet been named. Deputy Director Michael Monroe is considered a strong candidate.