An appeal is to be lodged with An Bord Pleanála against a decision to grant planning permission for apartments in the 17th-century Kilmainham Mill.
Kilmainham residents and trustees of the gaol museum agreed at a public meeting to lodge two separate appeals against the decision of Dublin City Council.
The permission is for the five-storey mill building in Kilmainham village to be converted into 10 apartments and for a two-storey annexe to become a duplex apartment. One of the conditions is that the facade of the listed building be protected.
Mr Damien Cassidy, chairman of the board of trustees of the museum, said the development was not acceptable.
"We intend to take the two appeals during the next two weeks. The mill is 17th-century and is the last example of a working mill in Ireland to our knowledge," Mr Cassidy said.
The mill went back to monastic times with connections to St Minan from whom Kilmainham got its name, he said.
"They say the outside of the building is to be protected but we don't want any new building on that part of the South Circular Road. The museum is just in front of the mill," he said.
The applicant for development of the mill is Charona Ltd.