Climate Objectives and Planning: A Review of the Decision of Coolglass Windfarm Limited v An Comisiún Pleanála

Introduction

The Supreme Court delivered a significant judgment in the case of Coolglass Windfarm Limited v. An Comisiún Pleanála [2026] IESC 5 on 5 February 2026 dismissing an appeal made by An Comisiún Pleanála (the "Commission") against the High Court's ruling which quashed the Commission's decision to refuse planning permission to Coolglass Wind Farm Limited ("Coolglass") for a wind farm development.

Background to the Case

Coolglass applied to the Commission for the development of a 13-turbine wind farm and associated works in County Laois. The Commission refused the application for planning permission in August 2024 as the proposed turbines were located in areas designated as "not open for consideration" under Policy Objective CM RE 7 of the Laois County Development Plan 2021-2017 ("LCDP") and Policy Objective WES 7 of the Laois County Wind Energy Strategy and would have significantly impacted the visual integrity and character of the landscape.

High Court Case

Coolglass applied for and was granted leave to apply for a judicial review of the Commission's decision. It sought inter alia:

1. an order of certiorari quashing the decision of the Commission to refuse permission;
2. a declaration that the Commission, in failing to approve adequate planning applications to meet Ireland's 2030 renewable energy targets in the Climate Action Plan 2024, failed to comply with its obligations under p 15 of the Climate Action and Low Carbon Development Act 2015 (as amended) (the "2015 Act"). p 15 provides that a relevant body shall, "in so far as practicable, perform its functions in a manner consistent with-(a)the most recent approved climate action plan...(d) the furtherance of the national climate objective and (e)the objective of mitigating greenhouse gas emissions and adapting to the effects of climate change in the state"; and
3. an order remitting the decision back to the Commission.

Two of the core grounds of challenge were that 1) the decision to refuse was invalid as the Commission erred in law by failing to adhere to its obligations under p 15 of the 2015 Act and 2) the Commission had failed to exercise its discretion to grant a permission which was in material contravention of the LCDP under p 37G and/or 37(2)(b) of the Planning and Development Act 2000 ("PDA 2000").

In the High Court Mr Justice Humphreys granted the order of certiorari and an order remitting the matter to the Commission to consider the application again finding, inter alia, that the Commission had failed to exercise its powers in a manner compliant as far as practicable with the climate objectives and policies outlined in p 15 of the 2015 Act. The court indicated that there was a strong presumption in favour of the grant of a permission for a renewable energy project however considerations of proper planning and sustainable development can have the effect of leading to a refusal of a permission but it must be assessed "in an evaluative way that furthers climate goals".

Supreme Court Decision

The Supreme Court dismissed the Commission's appeal, albeit for different reasons than the High Court. Some key takeaways from the decision are as follows:

1) Nature of the Obligation under the 2015 Act

The Supreme Court held that p 15 of the 2015 Act, in particular the amendments effected in 2021, created a real and legal binding obligation on the Commission to perform its functions in a manner consistent with the climate objectives insofar as is practicable and the Commission's obligations could not simply be reduced to a "procedural obligation". Mr Chief Justice O'Donnell stated that "the evident purpose and effect of s. 15 of the 2015 Act is to strengthen obligations imposed upon bodies (including the Commission) and to make the performance of all functions consistent with climate objectives insofar as is practicable. That obligation is, in principle, enforceable by a court". The Commission failed in this obligation when it refused to grant planning to Coolglass on the grounds that the proposed development contravened the LCDP. The Commission is required to consider the 2015 Act where practical and it was held that it had failed to engage with the question of compliance in "any real and substantive way".

2) Substantive Consideration

The Commission erred in law by failing to engage with climate considerations in its recommendation, and ultimate refusal, of Coolglass's planning application. The Commission ought to have considered whether the wind farm's climate objectives justified a material contravention of the LCPD.

3) Traffic Light System

Whilst the Supreme Court dismissed the Commission's appeal from the High Court, it did sway from the "simple formula" adopted in the High Court decision and disagreed that climate goals in the 2015 Act automatically trump a local development plan. The Supreme Court noted that planning law is nuanced and such considerations are a balancing act in dismissing the High Court's "simple formula" noting that it is "much more complex than a traffic light system of climate friendly (go) (unless impracticable) and climate unfriendly (stop)."

4) A Presumption of Compliance

The Supreme Court held that the Commission is entitled to presume that a local development plan adopted is in itself compliant with climate objectives and the 2015 Act and that any decision consistent with such plan will itself be consistent with those objectives however it should be able to explain why the decision it has come to is indeed consistent with climate objectives.

Conclusion

The Supreme Court determined that the decision of the Commission and underlying report of the Inspector on which it placed reliance, did not address the fundamental question as to whether the Commission should have exercised its discretion under S. 37G(6) of the PDA 2000 in granting the permission even if it was in material contravention of the LCDP and therefore erred in law. The Supreme Court upheld the order of High Court on this ground.

The court was also of the view that the matter should be remitted to the Commission for the Commission to consider whether it should exercise its power under p 37G(6) of the PDA 2000 in light of p 15(1) of the 2015 Act however the court invited the parties to submit brief subsmissions as to the appropriate order to made in this regard.

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