Mayor Marion Barry Jr. began an effort yesterday to gain control over booming development in downtown Washington and to try to build a consensus on what the city's core should be like 20 years from now.

The mayor named banker Luther Hodges Jr. to head a 42-member committee of owners of big and small businesses, downtown residents and political leaders that will recommend a new plan for rebuilding the downtown area.

The committee's job will be to tell city officials how to shape the future of the neighborhood between the Capitol and the White House north of Pennsylvania Avenue and south of M Street NW.

Changes in zoning and building size limits, new traffic and public transit plans, and efforts to preserve and promote small business, landmark buildings, Chinatown and the retail core are expected to be suggested when Hodges' group completes its work early next year.

The committee will work from a new plan for "A Living Downtown Washington, D.C." that was released yesterday by the city planning department and the "Downtown -- a People Place" proposal made a few months ago by the Metropolitan Washington Board of Trade.

Among the choices being studied by the committee:

Finding a new use for the downtown campus of the University of the District of Columbia at Mount Vernon Square and Massachusetts Avenue. UDC enrollemnt is declining.

Revising the zoning laws that limit the height of buildings. Clusters of tall buildings "symbolize the city's ability to attract investors and business," the report says. "Washington lacks this kind of focal point because of the height limit."

Granting property owners the right to sell "developmental rights" to their land to other owners. Thus, the owner of a historic three-story building might sell the right to put up a 10-story structure on that land to the owner of a neighboring site, allowing the buyer to put up a bigger building than normally allowed.

Restricting vehicle traffic on F and G streets to make them more attractive to shoppers, but opening up the Gallery Place pedestrian mall.

Developing "a concentrated retail core between 10th and 15th streets" rather than trying to maintain the present elongated core stretching three blocks further east to 7th Street.

Encouraging construction of housing downtown -- a goal that city and business groups agree is desirable, but neither has yet figured out how to accomplish.

Finding means of preserving and encouraging small and minority-owned businesses in the face of rapid development that pushes real estate prices so high that only big, well-financed businesses can afford to do business downtown.