Despite a unanimous rejection of Harvard's proposal to demolish a historic building, a city official said yesterday that the vote is more a call for new plans than an outright objection to developing the site.

The Cambridge Historical Commission voted Friday that the 93-year-old building at 10 Mt. Auburn St., a Harvard property since last summer, is historically significant--which automatically puts a six month stay on any demolition and renovation plans.

But Charles M. Sullivan, the commission's executive director, said yesterday that the eight-member board would reconsider the six month delay if the University works out a suitable alternative.

He added that the commission would probably not use its perogative to petition the City Council to declare the building a protected landmark, which would prevent construction altogether.

Harvard's Plan

Harvard presented four construction models to the Historical Commission, three of which call for the current structure's demolition. The resulting building would contain 50 apartments for graduate students and junior faculty and retail space on the ground floor.

University officials said last week that their architects tried to devise a plan which would incorporate the existing Queen Anne style building into the final structure. But such plans, Harvard said, would be economically impractical.

Jacqueline O'Neill, associate vice president for government and community affairs, said the University is cager to make a compromise and construct something on the site.

"We will use this moratorium to bring all parties to the negotiating table," she said earlier this week.

Neighborhood Reaction

Most residents of the neighborhood surrounding 10 Mt. Auburn St. who attended Friday's bearing said they were opposed to the University's proposed demolition of the building.

Several also expressed concern that the building could remain vacant and open to vandalism while the commission and the University debated its future.

But Harvard officials were just as concerned about the construction delay. "Nobody likes a vacant building," O'Neill added.

"In any project where you are delayed there's no question that it will cost you something." Robert A. Silverman, director of planning, said Friday.

In a related issue, the Cambridge Rent Control Board will have to decide whether the building falls under the city's stringent rent control laws when Harvard converts it to affiliated housing.