The house was always a magnet. For many years the late Alice Roosevelt Longworth's residence near Dupont Circle was the center of one of Washington's important social circles. Later it became a place of memories.

But since her death in 1980 at 96 it has stood empty.

Now the longtime home of Theodore Roosevelt's daughter and House Speaker Nicholas Longworth's wife is being turned into offices, under a plan that has drawn opposition from some in the neighborhood and praise from many others.

Renovation work began last month on the limestone beaux arts-style house at 2009 Massachusetts Ave. NW and an adjacent one, bought by Mrs. L. (as she became known) for her granddaughter, Joanna Sturm. The family still owns both houses.

Under the renovation plan approved by the District's Board of Zoning Adjustment and the federal-city Joint Committee on Landmarks, the two houses will be joined. A small addition will be built in the rear to house bathrooms and an elevator for the 40 office workers who are expected to occupy the 9,600-square-foot site.

More than 50 area residents wrote letters to the zoning board supporting the project. It has the approval of the Advisory Neighborhood Commission (ANC-2B) and the Dupont Circle Conservancy. Conservancy President Charles J. Robertson, an official of the National Museum of American Art, said his group likes the plan because the houses' interiors will be preserved.

Opponents of the conversion include the usually pro-preservation Dupont Circle Citizens Association, a majority of whose members favor keeping the buildings residential. The neighborhood has lost 25 percent of its housing stock to development in the last decade.

"I just don't believe it's a unique case. There are lots of residences with preserved interiors," said Anne Sellin, an art historian and chairwoman of the Citizens Association's zoning committee. Coincidentally, she is Robertson's sister.

"Architects say that they can't save these insides and retain neighborhood buildings as housing , but they're only looking for a way to get the highest return on the investments," she said.

ANC chairman William Middleton Jr. wrote a strong letter dissenting from the body's decision last fall to support the plan. He said he objects to any loss of residential usage in the area. The area's current zoning was intended to serve as a buffer between residential and commercial sections that adjoin it, he said.

"How can a zone serve as a buffer if it has been depleted of its residential uses and for all practical purposes is commercial use?" Middleton said.

Others in the area have voiced concern that office buildings generate less tax revenue than residences, create more traffic and contribute to a deserted appearance at night.

"Any residential neighborhood which accedes to the change of zoning from residential to office space is committing suicide. Never, never, never!" said Joe Grano, Rhodes Tavern preservationist and head of the Citizens Association.

The plan's strength, both its opponents and supporters agree, is that it will preserve the interiors of the structures as well as their noteworthy exteriors.

Alice Longworth's house, built about 1911, was designed by Jules Henri de Sibout, who also designed the National Trust for Historic Preservation building, at 1785 Massachusetts Ave., and the Canadian Embassy, across the street at 1746.

When her only child died at 31, Alice Roosevelt Longworth made sure that her granddaughter, still a child, would be provided for, and she bought the neighboring house for her.

Sturm's house, designed by architect George Oakley Totten and built in 1901, is also generally in the beaux-arts style, but incorporates other styles as well.

Alice Roosevelt married Ohio congressman Nicholas Longworth in 1906. Shortly after he became speaker of the House in 1925, they moved to the Dupont Circle site where, after his death in 1931, she held court for nearly half a century more.

At one point she grew poison ivy in the front yard, perhaps as a challenge to those who too readily accepted the invitation she'd embroidered into her often-mentioned sofa cushion: "If you haven't got anything nice to say about anyone, come and sit here by me."

More than a year after Alice Roosevelt Longworth died in February 1980, Sturm contracted with architect and designer David M. Schwarz--who had gained recognition for his restoration of nearby town houses and for a new commercial building in the 1700 block of Connecticut Avenue--to renovate the pair of houses.

Schwarz said he considered several options for the houses, including use as a single-family home, condominium or rental apartments, before the office conversion was decided upon. He said the chosen design is appropriate for the site, which is between a hotel and a town house-turned-office. The rest of the block is occupied by embassies and trade associations.

"She was a grand old lady, and it's a grand old house," local architect John Wiebenson commented. "It's sad though, that Alice Roosevelt Longworth will be the last person to live there."