The Historical Commission did not include the annex of the chapel--where the congregation's Sunday school meets--under the landmark designation. The annex, built in the 1960s, is home to the reverend's office.

Sullivan said the Historical Commission would be open to developers replacing the annex with a building of comparable size.

Meanwhile, the council adopted a motion requesting the Law Department and the Historical Commission to conduct a study on the possibility of designating interiors as historical landmarks.

Although Harvard supports the land-marking of the exterior of the chapel, Power said the University would not necessarily be in support of a measure allowing the city to designate any building's interior a historical landmark.

"It could potentially discourage adaptive reuse of historic properties," Power said. "Many of Harvard's properties are historic. If the landmark were to include the interior space, it might make it more difficult for Harvard to support land-marking in the future."

According to Charles M. Sullivan, chair of the Historical Commission, the commonwealth of Massachusetts only allows Boston building interiors to be designated as landmarks.

Until that happens, the building, if sold by a financially strapped School of Religion, could still cease to be a church.