A Cambridge ordinance designed to limit institutional expansion will probably control both the use and density of institution-owned buildings, a city planner said yesterday.

All current institutional land holdings have been catalogued and mapped, the official, who said the ordinance will be ready for a council vote as early as February, said yesterday.

"We're developing a categorization scheme for types of institutions and for the type of use--how many people and cars it will attract," Don Balcom, the city official drafting the bill, said yesterday.

Balcom explained that different limits might be placed on universities than on church schools. "We are looking for what's appropriate for a given neighborhood," Balcom said.

The city council instructed the planning office to draw up the ordinance last summer after obtaining state approval for the plan.

"Institutions are among the greatest destabilizing factors for our neighborhoods--they are like monsters eating up our city," councilor Mary Ellen Preusser told the council at the time.

Harvard is exempt from the ordinance because of its special protection under the state constitution.

City councilor-elect David Sullivan, however, has said he will introduce a resolution to eliminate that exemption at the state level after he takes office in January. "We should at least not have the exemption specified in the legislation," Sullivan said.

The council had asked that the ordinance be drafted by the end of the year. "We will have our basic approach outlined by Christmas," Balcom said yesterday. "But we have tried to go very slowly and deliberately on this, we are breaking new ground, and writing new law," he added.

Lewis Armistead, a Harvard community relations official, refused comment on the proposed ordinance. "It's all hypothetical at this point," Armistead said.