The Land Development Agency (LDA) wrote to several local authorities asking them not to include properties they hoped to develop for a vacancy tax intended to encourage the building of homes.
In correspondence with councils, the LDA said it would be "premature" for sites they were involved in to be considered subject to the residential zoned land tax (RZLT).
This will be calculated at 3% of the property's value next February.
The agency told Dublin City Council they were hoping to develop housing on two sites in the capital, St Bricin's Military Hospital in Dublin 7 and the former St Teresa’s Gardens estate in Dublin 8.
On St Bricin’s, they said the site was still being used by the Defence Forces and while it was intended to phase out operations there, this was going to take some time.
They told the council they were in the process of commissioning a feasibility study to see how heritage buildings at the military hospital could be reused to provide housing.
"We have key concerns about the barriers and challenges, in particular [the] cost in adaptive reuse and the availability for funding streams [and/or] financial support," the LDA said.
"The inclusion of the building and lands on the RZLT will raise additional costs relative to the consideration of timeline of transfer of lands or purchase of sites and financial exposure," they added.
The LDA said they were aiming to develop 543 new social and cost rental houses on the site of the former flat complex at St Teresa’s Gardens, planning for which was granted in June.
At the time, the Land Development Agency were still awaiting a decision from An Bord Pleanála and said making the site subject to additional taxes could hit their plans for the site.
"The premature identifying [of] sites on the RZLT map will have a further impact on viability and [the] cost of affordable residential units," they said.
In correspondence with Dun Laoghaire Rathdown County Council, the LDA also raised concerns over the inclusion of the former site of the Central Mental Hospital in plans for the zoned land tax.
The LDA explained how they had been granted a ten-year grant of permission for development of a mixed use scheme that would include 977 residential units along with a community centre, childcare facility, and medical centre.
The letter said: "The LDA consider the inclusion of the Central Mental Hospital is premature as the building has only recently been vacated [and] the building is not yet cleared of artefacts, furniture and a miscellaneous of other items."
It said there were also question marks over the "adaptive reuse" of buildings on the site and whether it would be viable to convert them for residential use.
The LDA wrote as well to Cork City Council about land in Kilbarry that was listed for transfer to it from the IDA under the Housing for All plan.
The agency said inclusion of the land for the residential tax could end up having an impact on the "affordability" of housing that would be built there.
In addition, it said the site was not yet "appropriately serviced" and that infrastructure would need to be developed before any new housing could be provided.
Asked about the records, a spokesman for the LDA said they had nothing further to add.
Reporting by Ken Foxe
