The “Mc Gowan Principles”
Particularity, Consistency and Developer-Control in Irish Planning Judicial Review

1. Introduction

Mc Gowan & Anor v An Coimisiún Pleanála ([2025] IEHC 405) is a significant High Court judgment delivered by Humphreys J on 16 July 2025. Aileen Donagher McGowan and the Mayo Sligo Energy Concern Group sought to quash An Coimisiún Pleanála’s decision granting permission for a 13-turbine wind-farm, sub-station, grid connection and hydrogen plant straddling Counties Mayo and Sligo. They mounted a three-fold attack:

1. EIA allegedly defective for failure to assess ongoing turf-cutting.
2. Alleged misinterpretation / material contravention of the Mayo County Development Plan and Renewable Energy Strategy.
3. Alleged failure to carry out a “joint” EIA with the EPA and absence of monitoring conditions.

Humphreys J dismissed the challenge in its entirety, refusing a late amendment and ordering the pleadings to be pared back. The judgment consolidates, clarifies and—for some points—extends earlier case-law on (1) pleading rigor, (2) onus of proof in planning JR, (3) preclusion where the applicant argued the opposite before the decision-maker, and (4) the limits of conditioning land outside a developer’s control.

2. Summary of the Judgment

• Pleadings & Amendment: A proposed new ground (¶84A) alleging inconsistent biodiversity methodology was refused because it could have been raised at the outset, lacked explanation and would have prejudiced the expedited timetable.
• Ground 2 (Development Plan): Rejected for want of particularity, for factual inaccuracy (the plan & RES were in fact considered) and because the Board lacked power to impose conditions on land and turbary rights it did not control.
• Ground 1 (EIA—Turf Cutting): Failed on pleading, proof and merits. The Inspector and Board had assessed turf-cutting; applicants offered only assertion, no expert proof; and their position before the Board had actually supported turbary rights.
• Ground 3 (EPA / Joint Assessment): Dismissed as misconceived—EU and domestic law do not require centralised or “joint” assessments and the EPA had, in fact, been consulted.
• Costs & Orders: Proceedings dismissed; applicants directed to file a cleaned-up statement excluding the refused ground; no order as to costs unless parties apply.

3. Analysis

3.1 Precedents Cited and their Influence

• Burden of Proof & Particularity: Meadows, Sherwin, Ballyboden, Concerned Residents of Treascon, among others, were relied on to re-affirm that (i) applicants carry the evidential burden to show an illegality and (ii) Order 84 r.20(3) demands precise grounds. Humphreys J applied these to strike down sprawling, “kitchen-sink” pleadings.
• Esprit d’escalier / Inconsistent Case: North Great Georges Street, Clifford, Ballyboden demonstrated that applicants cannot ambush the decision-maker or contradict their own earlier stance. This was fatal where the Concern Group previously sought preservation of turbary rights but later claimed the Board should have extinguished them.
• Multiplicity of Consents: Concerned Residents of Treascon line of authority clarifies that EU law tolerates multiple consenting authorities. Thus, absence of a “joint EPA–Board” EIA was not unlawful.
• Limits on Planning Conditions: Weston v An Bord Pleanála and Shadowmill endorsed the view that conditions cannot regulate land outside the applicant’s control—central to rejecting the demand to stop third-party turf-cutting.

3.2 Court’s Legal Reasoning

1. Pleading Failures – The Court dissected each ground, showing they were either (a) unparticularised, (b) internally contradictory or (c) merits-based disagreement dressed up as law. Order 84 was applied robustly.
2. Burden of Proof – Applicants supplied opinions, rhetoric and selective quotation but no admissible expert evidence capable of rebutting the Board’s assessment on biodiversity, GHG or hydrology.
3. Developer-Control Principle – Section 34(4)(a) PDA 2000 only allows conditions regulating “land … under the control of the applicant.” Seeking cessation of turf-cutting on lands the developer did not (and could not) own was therefore ultra vires and irrational. If such a restriction were essential, the correct outcome would have been refusal, not conditional approval.
4. Consistency Doctrine – By lobbying for turbary access during the application process the applicants forfeited the right to argue the exact opposite in court.
5. No Mandatory Joint EIA – Article 2(3) EIA Directive permits multiple authorities; domestic ss.173A & 173D simply facilitate, they do not compel, joint assessment. The EPA’s two submissions satisfied the consultation duty.
6. Reasons – Applying Connelly, Killegland Estates and Sherwin, the Court held the Board’s order, inspector’s report and ecologist’s report collectively supplied the “main reasons on the main issues”.

3.3 Likely Impact of the Judgment

• Pleading Culture: Mc Gowan will be cited to resist diffuse, policy-heavy, evidence-light pleadings, especially in environmental JR. It fortifies the trend towards “forensic, ground-by-ground” statements.
• Strategic Litigation Strategy: NGOs and objectors must now weigh carefully any inconsistent submissions during the administrative stage; inconsistency may bar subsequent relief.
• Planning Conditions Jurisprudence: The express linkage between s.34(4) and applicant control clarifies that boards and planning authorities cannot impose restorative or preventative obligations on third-party land through a permission. Developers and authorities alike gain certainty on the scope of permissible conditions.
• Multi-Consent Projects: The endorsement of separate yet coordinated assessments (Board / EPA) supports the State’s existing “split” system for windfarms with ancillary power-generation or IPPC elements.
• Climate-Focused Objectors: The case signals that climate-based objections must be (a) pleaded with precision, (b) supported by expert evidence and (c) tied to an actual legal duty of the decision-maker, not aspirational policy alone.

4. Complex Concepts Simplified

• Pleading Particularity (Order 84 r.20(3)) – A JR statement must set out each legal ground, the facts relied on and the causal chain to the relief. Vague claims like “breach of the EIA Directive” without specifying which article/how/why are inadmissible.
• Turbary Rights – Ancient Irish property right allowing holders to cut turf (peat) for fuel. A planning applicant cannot unilaterally extinguish third-party turbary rights.
• Joint / Coordinated Procedure (EIA) – Article 2(3) enables Member States to run parallel processes (e.g., planning + EPA licence) so long as cumulative effects are eventually assessed; it does not force a single “joint” decision.
• Material Contravention – A development that significantly conflicts with a development plan. Even then, the Board may still grant permission under special statutory grounds, but applicants must identify the specific policy breached.
• Net Biodiversity Gain – A planning concept where, after mitigation/offset, a project delivers more or better habitat than existing baseline. The Inspector calculated gain because windfarm works end turf-cutting on controlled plots and add a 10.6 ha restoration area.

5. Conclusion

Mc Gowan & Anor v An Coimisiún Pleanála crystallises a trio of practical rules—the “Mc Gowan Principles”:

1. Plead with Surgical Precision. Wide-angle, policy-laden pleadings are vulnerable; every ground must map facts → legal duty → breach → remedy.
2. Maintain Consistency. What you ask of the decision-maker binds—or haunts—you. Courts will not entertain an about-turn.
3. Respect Developer-Control Limits. Conditions cannot commandeer land or rights the applicant does not own; climate or biodiversity aspirations cannot override that basic jurisdictional brake.

By applying these principles the Court dismissed a high-profile renewable-energy challenge and, in doing so, provided a clear, workable framework for future planning judicial reviews. Objectors must now marshal precise, evidence-based, legally tethered complaints, while decision-makers can rely on Mc Gowan to defend permissions where they have: (1) documented a coherent EIA, (2) explained their main reasons, and (3) stayed within their statutory lane.