Planning permission granted to Cairn for over 300 new homes in Blessington

Seán McCárthaigh

Planning permission has been granted to one of the country’s largest building firms to construct over 300 new homes in Blessington, Co Wicklow despite fears by a community group and anglers on the River Liffey that the development would increase the risk of water pollution in the area.

An Coimisiún Pleanála approved the application by Cairn Homes Properties Limited for the construction of 329 residential units on a 25-hectare site to the north-west of the town close to the Wicklow-Kildare border.

The ruling was a reversal of a decision made by the Commission last year under its former identity as An Bord Pleanála.

The site is part of the 63-hectare historic Blessington Demesne which is now owned by Cairn Homes and includes the ruins of Downshire House which was burnt down during the 1798 Rebellion.

The Commission rejected appeals by both the Ballymore Eustace Trout & Salmon Anglers Association and the Ballymore Eustace Community Development Association against the decision of Wicklow County Council to grant planning permission for the large-scale residential development.

Subject to compliance with a number of planning conditions, the Commission said the proposed development would provide an acceptable quantum of residential development at the location which would be served by an appropriate level of physical and social/community infrastructure.

It noted that the project would also provide an acceptable form of residential amenity for future occupants and would not seriously injure the visual amenities of the area or impact on other properties in the vicinity.

The Commission said the development was also acceptable in terms of urban design, height and scale as well as traffic safety and convenience.

It was also satisfied that it was not at risk of flooding or causing flooding on other lands while the water supply infrastructure would not adversely impact on water quality or services in the area.

The proposed development by Cairn Homes had originally been approved by Wicklow County Council despite materially contravening a local area plan for Blessington.

However, it was subsequently successfully appealed to the commission’s predecessor, An Bord Pleanála, by the Ballymore Eustace Trout & Salmon Anglers Association and the Ballymore Eustace Community Development Association.

In a split decision in September 2024, the board allowed two elements of the plan to proceed – a new 10.65-hectare town park and a 700-metre extension to the Blessington Inner Relief Road – but refused planning permission for the residential development.

In May 2025, however, the High Court quashed the decision of the board to refuse planning permission for the 329 homes following a judicial review sought by Cairn Homes.

The court directed that the case should be remitted back to the Commission for a fresh determination.

In a new report, an inspector with An Coimisiún Pleanála acknowledged that there had been significant changes to national and local planning policy in terms of the recognition of the need to plan for increased population growth since the original ruling on the development was first made.

The inspector said the changes provided for greater flexibility on the matter of zoned land and the ability to exceed projected housing and population targets.

The appellants had raised concerns about the capacity of the local wastewater treatment plant in Blessington to cater for the large-scale residential development proposed by Cairn Homes.

The two groups also complained that Blessington Lake – which is the largest drinking water supply reservoir in Ireland – was already affected by major algal blooms.

They claimed water quality in the area was not what it should be even before the proposed development was considered.

They argued any development that posed a further risk to such waterbodies should not be approved.

The Ballymore Eustace Community Development Association said the issue was also about the heightened pressure on the River Liffey with 40 per cent of its waters already extracted from Golden Falls near Poulaphouca to cater for the drinking needs of Dublin’s population.

The group claimed there were some towns like Blessington that were just not suitable for further development with their current infrastructure.