The demolition of the 19th-century Presbyterian church in Sandymount, Dublin, is to go ahead despite protests from local people, supported by An Taisce.
Ms Linda Ray, residential services manager, of the Presbyterian Residential Trust, said: "We are looking at it from a safety perspective and the way we can best meet the needs of the community."
The church, in Tritonville Road, has been derelict for the past 20 years, she said. There is a dry rot fungus in the building and a crack in the structure.
"We have had no other option, because of the dry rot, but to demolish the building.
"We really want to be meeting the needs of the community and the best way we feel we can do that will be to build sheltered housing."
The church already operates sheltered housing behind the building and has received planning permission for an additional 14 units and eight two-bedroom apartments.
The site for the apartments may be sold to a developer to fund the building of the sheltered housing. Two sisters from the area, Ms Barbara and Ms Hilary Tonge, began protesting outside the church railings on Tuesday when earth-moving equipment was brought in to prepare the area around the church for the demolition.
Ms Barbara Tonge said she was protesting because "I believe buildings like this should be preserved as part of our heritage".
With friends and neighbours they have put up placards and have received 600 signatures for a petition calling for the building to be saved.
Their banners included the messages "Don't destroy our heritage" and to passing traffic "Beep if you support us".
Ms Tonge said: "I am optimistic until the very last."
She added that "because architects are so good these days, they should surely be able to incorporate the church into any ideas they have for developing the sheltered housing. I've heard they've done this in Germany".
She added that while the building had been condemned it was being used up to last year for Irish dancing.
However, Ms Ray said it was the hall attached to the church which had been used up to about a year ago. She said the plans for the site included the provision of an area for community use. The Presbyterian Church reiterated in a statement that it "has at all times tried to follow correct procedures and to obtain all necessary approvals before taking any action in this matter. It is always willing to listen to the concerns of others, provided those concerns are expressed in the proper way at the proper time.
"We value our architectural heritage highly and seek to preserve it where possible, but this cannot be our only concern. Churches are not merely monuments to the past."
An Taisce has appealed to the Presbyterian Church to hold off on the demolition, and Mr John Gormley, the local Green Party TD, said that while it was accepted the church had followed the procedures correctly, nobody had been aware until recently that the demolition was planned.
