Cambridge last week decided not to give landmark status to a century-old Mass Ave building complex, including the last attempt by community activists to prevent the construction of a new primarily residential building in its place.

Area residents say that the loss of the three Central Square office buildings, which house many of the area's artist studios and human rights groups, will destroy the diversity of that community.

Thursday's controversial 3-2 vote by the Cambridge Historical Commission marked the culmination of five years of debate over the three buildings located on Mass Ave and Essex Street, said Charles M. Sullivan executive director of the Historical Commission.

In 1982, the Commission first voted to let the building's owner, Jay Schochet, demolish the buildings. Schochet did not destroy the buildings then, perhaps because "the interest rates were too high to make the project work," Sullivan said.

But in 1986, when Schochet again requested permission to raze the complex, the Commission imposed a six-month delay on the proposed demolition, before eventually deciding that the complex "didn't warrant a designation" of landmark status, Sullivan said.

Schochet was unavailable for comment yesterday.

Tenants of the three buildings, located on 595-605 Mass Ave, were ordered last fall by Schochet to leave the complex by March 31, Sullivan said.

In its place, Schochet Associates is proposing to construct a seven-story building for office space and apartments, including 24 units for low-to-moderate-income housing units, said Clifford A. Truesdell '66, vice-chair of the Area 4 Neighborhood Coalition, a Central Square group which supported the demolition.

Truesdell said Area 4 is supporting Schochet's latest proposal for the demolition of the complex, after opposing it for the last five years, based on the merits of the latest development proposal. Unlike Schochet's two previous construction plans in 1982 and 1984, the current plan includes "well-designed" low-income housing, said Truesdell.

This new complex "is going to be one of the best buildings in Central Square," Truesdell said. "The city needs housing," he said.

But other area residents, who opposed the razing at recent City Council meetings, said yesterday that the buildings are "historically valuable," and their demolition will end the cultural diversity for which the area is known.

"The cultural diversity in Central Square is an issue right now. The building houses cultural groups which remain true to the spirit of the original builder," Aileen S. Y. Chong-LeBlanc, a dancer who used to work at 595 Mass Ave.

"The artists keep getting pushed into the background."