D.C. historic preservation staff members recommended this week that the Hillandale mansion, once the residence of a Standard Oil Co. heir, be designated a historic landmark and preserved.

The 65-year-old mansion, inspired by Italian villas and farmhouses, has been the subject of dispute among the real estate developers who own it, preservation-minded neighbors and the French government, which fears the mansion's demolition would make way for the construction of homes that could be used to spy on its embassy on nearby Reservoir Road.

The controversy arose most sharply this spring after the D.C. Zoning Commission voted to modify a development plan and permit the developers, Sur Developers/Builders, to tear down the mansion and build 13 single-family detached homes as part of the Hillandale development.

The preservation recommendation was made to the D.C. Historic Preservation Review Board, which Wednesday delayed ruling on the historic landmark designation until next month.

If the panel decides to designate the mansion as historic, by adding it to the D.C. inventory of historic landmarks, the building may not be demolished or altered without the Review Board's approval. If the board denies the landmark designation request, made by a group called Friends of Historic Preservation Inc., Sur could replace the structure with houses.

"Despite years of neglect and the loss of significant portions of its original site, Hillandale remains a distinctly American interpretation of the northern Italian farmhouse, which is comparable in its scale and character to other large estates seen throughout the areas to the north and west of Georgetown," said Glen B. Leiner, principal historian of the D.C. Historic Preservation Division.

After hearing almost a full day of testimony for and against preserving the mansion, the Historic Preservation Review Board said it would study the site of the mansion on July 5 and make its decision on July 11.

When it visits the site it will find a development of town houses that have been built or are being built on the grounds of the estate.

The loss of those grounds to development is key to one argument against granting the mansion historic landmark status, said William Lebovich, an architectural historian retained by Sur. Lebovich said the mansion derived its architectural integrity as a villa from its siting on grounds that were used for grazing.

Thomas L. Shumacher, a University of Maryland professor of architecture retained by Sur, said the mansion had only cosmetic Italianate features, but that its overall plan was more Anglo-American. He said this blending of features fails to render the house a significant architectural landmark.

Historians Stephen and Hasia Diner, also hired by Sur, testified that their research suggested the home's original owner, Anne Archbold, had very little influence on Washington. "There is no evidence that she was a significant figure," said Stephen Diner, a historian at George Mason University.

Residents of the Hillandale town house development said the run-down structure is an "eyesore" and a "hazard" to the community.

However, Emily Iag, an architectural historian with Traceries, a consulting and research firm retained by the French government, testified that the mansion was an example of how American homes built in the 1920s were influenced by features and plans of structures found throughout Europe.

Iag said the mansion's architect, Josephine Wright Chapman, was a historic figure, one of the nation's first female architects. Chapman, who was trained in Boston at the turn of the century, devoted most of her career to designing residences.

Archbold was a historic figure in Washington, Iag said, because of her contributions of land to the Archbold-Glover Park and money to a hospital and her association with internationally known artists who visited Hillandale while in Washington.