A 115-year-old building on the Saint Mary's University campus was demolished Friday, despite pleas from a prominent heritage group that fought to save the Halifax Infants' Home.

The home was built in 1899 for single women and their children. The university bought it in 1998 from the Salvation Army and used it for classroom space until last fall.

The university said the building needed an expensive renovation if it were to be used again.

Bringing it back to good condition would cost an estimated $10 million while repurposing it would cost $13 million, the university said.

"While there was interest in the building, there was nobody, or individual, who was stepping forward with that level of investment," said Margaret Murphy, the university's vice-president of external affairs.

"We did take the time to study it, review the options, meet with the heritage groups and then report back to them at the end of the day with our conclusion."

But the Heritage Trust of Nova Scotia disputes the cost estimates. The group said one local architect, Syd Dumaresq, suggests the building could have been made "functional" at a third of the cost put forward by the university.

The group argued it may have been possible to find a donor willing to shoulder the lower cost and it is unhappy the university has torn down the building.

"It's a really important and, I think, neglected piece of our heritage in Nova Scotia," said Peggy Walt with the Heritage Trust of Nova Scotia.

"This building was built by women, for women, back in the day when there weren't a lot of social services being provided through government and things like that."

Walt said this should be the time to put an emphasis on women's history, given the outrage last fall over the frosh week chant at Saint Mary's that was seen to glorify non-consensual sex.

Saint Mary's University bought the building because it was interested in the land at the corner of Tower Road and Inglis Street.

The building housed the university's Teaching English as a Second Language Centre. The students were moved out in the fall of 2013 when a new ESL building opened.

Murphy said the Halifax Infants' Home did not have adequate space for students and it cost $300,000 a year to "keep the building just standing."

"That's money that can be better spent on students," she said.