Washington sculptor Frederick E. Hart has proposed that huge sculpted panels be commissioned to humanize the FBI's long-criticized J. Edgar Hoover Building. The panels would memorialize the U.S. Constitution, perhaps in time for its 200th birthday.

In a letter to his fellow members on the Fine Arts Commission, Hart suggested the panels celebrate civil rights, women's suffrage and other constitutional milestones. Hart said the subject matter would be especially appropriate for the Justice Department, of which the FBI is a part. The presidentially appointed commission, which has esthetic jurisdiction over the architecture of the federal area, is expected to discuss Hart's proposal at its Feb. 21 meeting.

The nine 15-by-30-foot flat concrete panels on the pedestrian level of the Hoover Building's Pennsylvania Avenue facade (between Ninth and 10th streets NW) have long been considered an esthetic affront by architectural critics and others.

Charles Atherton, Fine Arts Commission secretary, called Hart's proposal "a nifty idea" that "would do much for the unbelievably bleak aspect of the FBI's inhumanld,10 facade. Then maybe we could do something more about the darkness and emptiness of the open space on the street level. Now it's eerie, uneasy and disturbing, like a surrealistic Italian movie of 1960."

Ever since the FBI building's completion in 1975 at a cost of $126 million, critics have deplored the building as an example of "Mussolini Modern." The design, by C.F. Murphy & Associates of Chicago, was intended in part to make the building bombproof, conceived as it was amid the urban upheavals of the 1960s.

Stanley Gladych, Murphy's chief designer, had proposed an arcade along the Pennsylvania Avenue facade, but the late J. Edgar Hoover, longtime head of the bureau, vetoed the idea as a security risk. In 1979, FBI Director William H. Webster also opposed such shops as potential routes for "electronic penetration" or explosives.

When the arcade plan was shot down, architect Gordon Bunshaft, at that time a member of the Fine Arts Commission, suggested the forbidding wall.

* At a meeting yesterday of the Commission on the Bicentennial of the U.S. Constitution (1987-1989), Atherton gave a copy of the Hart idea to Susan Falb, the FBI historian, and Mark Cannon, executive director of the commemorative commission.

Falb said the Hart letter was making the rounds at the FBI, but that no formal action on it had been taken. The Justice Department (across the street from the FBI), the National Endowment for the Arts and the Pennyslvania Avenue Development Corp. would also have to consider the plan. Funding for the sculpture would have to be appropriated by Congress.

"Carter Brown [chairman of the Fine Arts Commission] is out of town," said Atherton. "But he's grappled with the FBI esthetics for a long time. I know he's interested. Since Hart's letter went out, we've had several favorable calls from commission members."

Hart is the sculptor of much of the ornament of the Washington Cathedral as well as the heroic figures at the Vietnam Veterans Memorial.