And Dean Maurice Sirr of the Church of Ireland has said he would be surprised if objections were not submitted to City Council, before a decision is due on February 20.
The proposed building is on a site at the corner of Pery Square and Barrington Street, which architect Michael Healy is hoping to acquire for his own purposes.
Dean Maurice Sirr and representatives from Healy Architects presented the plans to the parents' council of the school before Christmas, where an open discussion followed.
"There was a very mixed reaction of course. Some people were adamantly against it. But whenever one looks at any new development, people aren't fully aware of how it could look and tend to fear it," said Dean Maurice Sirr.
Several parents are opposed to the plans as they believe they are not in keeping with the historic Georgian area of Pery Square.
"I suspect there are people who feel the school environment might be enfringed upon," he said.
The building is planned for a site adjoining the 170 year-old St Michael's Church, which is a protected structure, as are the lands surrounding it. However, Dean Maurice Sirr said details of the sale have yet to be finalised.
"From our point of view we've monitored the plans and feel it's a very handsome building. We are very content with the plans so far. We certainly felt it was a good plan and that the building is in keeping with the area," he said.
Local architect Michael Healy previously told the Limerick Leader that the people would "be paying tributes" to the building when the plans are publicly available.
"You can be assured that we want to be associated with an appropriate building. It will be carefully and sensitively designed for the site," said Michael Healy. He commented that it is certainly not the case that the building would ruin the look of the area.
The proposed development will contain a gallery/office/commercial unit on the ground and lower ground floor, an architectural studio on the first floor and a mezzanine level.
The principal of St Michael's School, Ms Rosalind Stevenson, was not available to comment.