Interaction of Ireland’s climate law and planning regime clarified

Louise McQuaid of Pinsent Masons in Dublin said the judgment issued by Ireland’s Supreme Court confirmed (94-page / 642KB PDF) has confirmed that the duties planning authorities face under climate legislation in the country are not absolute. This means it is within authorities’ discretion to refuse planning permission for climate-friendly projects.

Section 15(1) of the Climate Action and Low Carbon Development Act 2015, as amended in 2021, imposes a real and enforceable duty on public bodies to act “insofar as practicable” in a manner consistent with national climate objectives.

In January 2025, the High Court in Ireland interpreted this duty as, in practice, requiring planning authorities to “almost always” grant planning permission for renewable energy projects. This near absolute obligation to follow the aims of the climate law has, however, been watered down by the Supreme Court in its new ruling.

While the Supreme Court acknowledged that the duty arising under section 15(1) is significant, it confirmed it is qualified: it said public bodies must act "consistent with" climate plans but that this does not amount to a strict "comply with" obligation.

The Supreme Court recognised that full climate alignment may not always be feasible in specific situations. When assessing whether public bodies can be said to have met their duty under section 15(1), the Supreme Court said that judges in Ireland should ask if the decision taken by those bodies fell within the range of what's practically consistent with climate objectives given real world constraints.

According to the Supreme Court, the section 15(1) duty is just one factor among many that need to be weighed. It should operate as a climate “consistency” check on decisions, but within the wider context of the whole planning framework. It said: “The qualified consistency obligation imposed by s. 15(1) cannot be the sole or even principal determinant of the refusal or grant, or grant subject to conditions (subject to practicability) of planning permission”.

Further to this, the court confirmed that the local development plans that planning authorities in Ireland are responsible for developing, have primacy – providing they are aligned with Ireland’s climate laws. It said that only if a plan is demonstrably misaligned with updated climate targets or unduly restrictive in light of climate needs, should the authority consider overriding it.

The Supreme Court was considering how the section 15(1) climate duty applies in the context of a planning decision taken by Ireland’s planning authority, An Bord Pleanála, in a case involving developer Coolglass Wind Farm Limited (Coolglass).

An Bord Pleanála previously refused Coolglass planning permission for a 13-turbine wind farm in County Laois. It did so after determining that the proposed development would materially contravene the county’s development plan 2021-2027 – most of the proposed wind farm was to be situated in areas that were designated in the development plan as “not open for consideration” for wind farm development.

Coolglass lodged an appeal against that decision. Last January, the High Court ruled in the developer’s favour. At the time, the High Court ruled that the duties that public bodies in Ireland have under climate legislation trumped the development plan provisions and determined that An Bord Pleanála had been wrong to refuse Coolglass planning permission.

While the Supreme Court has now upheld the High Court’s decision on that matter, it has done so on narrower grounds. The Supreme Court held that An Bord Pleanála erred by not genuinely considering using its powers to grant planning permission, notwithstanding what the development plan provided. The authority had failed to weigh the project’s climate benefits at all, which the court said was an error of law.

Louise McQuaid of Pinsent Masons said: “The ruling represents an important recalibration of the legal landscape for renewable developers.”

“Section 15(1) remains a powerful tool, but this decision makes clear it’s not a silver bullet. Developers will need to engage more strategically with local development plans and ensure their climate arguments are robust, contextualised, and supported by planning policy,” she said.

“This decision provides welcome clarity for renewable energy developers navigating the planning system. While it confirms that climate obligations under section 15(1) are legally enforceable, it also reinforces the primacy of development plans. The key takeaway for energy clients is that climate alignment strengthens a project’s case but doesn’t guarantee approval – strategic site selection and early engagement with local planning policy remain essential,” she said.