Thornton Hall, on the site of the proposed new prison in north Dublin, is set to become a protected structure, following the recommendation of Fingal County Council's conservation department.
Councillors are likely to accept the recommendation at their monthly meeting on Monday, having previously requested the entire Thornton lands be made an Architectural Conservation Area (ACA) .
The council's conservation officer Fionnuala May will present councillors with a proposal which would see only Thornton Hall, a mid-19th century house to the east of the site, being placed on the Record of Protected Structures.
In her report Ms May says the two-storey house is of "significant architectural merit"; buildings of a similar style throughout Fingal county are included on the council's Record of Protected Structures. She had said previously that an ACA designation was not suitable for the site.
A preservation order referring to the house alone and not the surrounding lands is less likely to lead the council into confrontation with the Minister for Justice, whose department is already facing legal action in relation to the site.
The Government has full ownership of the site, including the house, having purchased it for €30 million last October.
High Court proceedings challenging the procedure adopted by the Minister in selecting the Thornton site, and claiming that the site is a national monument, are to begin on February 14th.
Fingal council engineer Richard Merne, Dunwater, Newbarn, Kilsallaghan, who is taking the action on his own behalf, claims the site is unsuitable, with inadequate water, sewerage and transport facilities.
Mr Merne also contends the Minister was required under an EU directive to carry out an environmental impact assessment prior to entering into the contract for the site but failed to do so.
While the council's plans to make Thornton Hall a listed building would make it an offence to damage the house or alter it without specific planning permission, this will not affect plans for the jail, a Prison Service spokesman said.
Under the Planning and Development Act 2000, a development by the State is exempted from normal planning procedures if it is intended for the administration of justice or national security.
However, Prison Service spokesman Jim Mitchell said it may not be necessary to demolish the house.
