Supreme Court refuses appeal in challenge to Ennis data centre

Ireland’s Supreme Court has refused opponents permission to appeal a High Court decision upholding approval for a planned €1.6 billion data centre outside Ennis, County Clare, RTÉ reported on 12 October. The decision closes this route of challenge to Art Data Centres Ltd’s project; the developer says further arrangements must be completed before construction begins.

According to RTÉ, the court found that the proposed grounds of appeal did not meet the constitutional threshold for permission to proceed. It said that ‘no point of general public importance arises.’ RTÉ reported the ruling, but the court’s determination was not retrieved for this account.

Why opponents challenged the Ennis project

The applicants were Colin Doyle, Friends of the Irish Environment CLG, Futureproof Clare, Martin Knox and Christine Sharp, RTÉ reported. They argued that emissions from building the data centre, and a failure to offset greenhouse gases, raised an issue of general public importance in light of climate targets. Their argument concerned the grounds for allowing an appeal as well as the environmental effects they said the project would have.

An Coimisiún Pleanála opposed the application. According to RTÉ, the planning commission argued that emissions alone did not establish exceptional circumstances and that the applicants overlooked its attempts to mitigate greenhouse gas emissions. The Supreme Court’s refusal means the opponents cannot take this proposed appeal forward on the grounds they presented.

What is planned beside Ennis’s Tulla Road

Planning permission was granted in April 2024 for six data halls on a 145-acre site beside Tulla Road, on the eastern outskirts of Ennis, according to RTÉ. The ruling removes the appeal route described in its report for a project that has spent years moving through planning and court processes. It does not itself mark the start of construction.

Data Center Dynamics reported in March 2026 that permitting and legal challenges had stretched over six years. It said the 145-acre parcel was rezoned in 2019. That history helps explain why a decision on leave to appeal matters to the project’s timetable.

The specialist publication described a proposed 200MW campus with six data halls and an 83MVA off-grid power source. Those are project specifications rather than operating figures. They also put the scale of the development behind the court dispute in clearer terms than the investment figure alone.

RTÉ reported the developer’s estimate of up to 1,200 construction jobs and up to 1,000 permanent jobs over the facility’s operational life. Both numbers are projections tied to the planned development.

Energy questions and the developer’s response

Electricity demand is part of the wider Irish context for the dispute. Data Center Dynamics cited Central Statistics Office figures showing that data centres accounted for around 20% of metered electricity consumption in Ireland. That national share does not measure the planned Ennis campus’s future use, but it shows the scale of the sector’s electricity demand.

Art Data Centres joint founders Tom McNamara and Vincent Fogarty welcomed the ruling, RTÉ reported. They said it recognised a future for what they called environmentally sensitive data centres, pointing to renewable energy, grid-supporting generation and heat recycling. Those are the founders’ descriptions of the project’s intended approach; its eventual environmental performance remains unknown.

The founders also called the decision good news for the campus and for Clare, describing the development as a pillar of the Ennis 2040 Economic Plan, according to RTÉ. Their response followed the applicants’ challenge over construction emissions and climate targets.

What remains before construction

The company said connection applications could now be processed and that work would begin in 2027 once everything was in place, RTÉ reported. That is a conditional forecast: the report does not establish that the connections have been completed.

In March, Data Center Dynamics reported that the first phases were then expected to go live by the end of 2028. That was an earlier target, not a confirmed schedule after the Supreme Court decision. The available reports do not establish a completion date or whether opponents will pursue another legal route.