An 1850s villa in the Mount Pleasant section of Northwest Washington now used as a home for the elderly had been designated a historic landmark, apparently frustrating plans of the Stoddard Baptist Home trustees to raze the structure and build a new facility.

"A much needed project has been brought to a screaming halt," John Hunter, president of the board of trustees of the Baptist home, said in a telephone interview. The organization had planned to build a 180-bed facility and had obtained a tentative agreement from the Department of Housing and Urban Development (HUD) for a $5.4 million loan. Processing of the loan stopped when the landmark application was filed, Hunter said.

Hunter said the trustees have asked their architects to perform a new design study of the project to see if it would be possible to build the facility while preserving the villa. The study would take about eight weeks and cost $20,000, according to Hunter.

"This additional expenditure and delay has thrown a monkeywrench" into the project, said Hunter. He added that the trustees were considering applying for a demolition permit in order to "move on both fronts."

Although the building is now protected by the landmark law, city officials can permit demolition of landmarks if, after hearings, they determine that it is necessary for a project of special merit.

But even if the Baptist home gets city permission to raze the structure, demolition would probably jeopardize the HUD loan. Laws prevent use of federal funds for projects that will have a negative effect on landmark properties.

The Joint Committee on Landmarks of the National Capital gave landmark status only to the original 1850s house, Ingleside, designed by Thomas Ustick Walter, architect of the Capitol dome. The committee did not include the wings added in the 1920s and 1930s. Don't Tear It Down Inc., the preservation group that sponsored the landmark application, had asked that the wings be included.

Because the wings are not landmarks, Stoddard Baptist Home officials would probably be allowed to tear them down and put new structures in their place. According to Terry O'Connor, an attorney for the Joint Committee on Landmarks, new structures would probably be subject to design review by the committee because they would be considered additions to the landmark structure.

Tom Conway, a member of a Mount Pleasant group called Patrons of the Adams House which backed the landmark application for the Baptist home, said in a telephone interview, that he had tried through the home's lawyer to set up a meeting with the trustees to discuss alternative plans and to offer assistance to obtain funds for the design study. According to Conway, the trustees have not responded to the request.