Plans for a major business and technology park in the grounds of Castletown House, Co Kildare, have been turned down by An Bord Pleanála.
In its ruling, the board said the proposed office-based scheme, incorporating 3,225 car-parking spaces, near an interchange on the M4 motorway, would be remote from public transport and not readily accessible by rail.
This would result in extensive use of the motorway by car-borne commuter traffic and tend to lead to traffic congestion at the interchange, it said, adding that this would be contrary to sustainable development.
The proposed development would also be contrary to the Strategic Planning Guidelines for the Greater Dublin Area, which seek to focus further development in north Kildare in areas accessible to public transport.
The appeals board also found that the location of the scheme planned by Janus Securities Ltd would contravene Kildare County Council's policy of maintaining the physical separation of Celbridge and Leixlip.
It would also materially contravene the development plan for the area, which has as one of its objectives the retention of the demesne lands associated with Castletown House for primarily agricultural use.
The nature and scale of the business park, consisting of 21 buildings, would "adversely affect the setting and character" of Castletown House notwithstanding a proposal to transfer 121 acres of land to amenity use.
An Taisce, which took the appeal, welcomed the board's decision, saying it amounted to "an indictment of the role of Dúchas [the Heritage Service] in protecting this great house and its surroundings".
Mr Ian Lumley, An Taisce's heritage officer, said it fundamentally disagreed with Dúchas for supporting the plan on the basis that an area of land near the house would be transferred to amenity use.
