Harmless Error, Irish-Language Obligations and Environmental Assessment:
Commentary on Wild Ireland Defence CLG v An Coimisiún Pleanála [2025] IEHC 726

1. Introduction

This High Court judgment, delivered by Humphreys J on 17 December 2025, arises from a challenge by Wild Ireland Defence CLG to a strategic infrastructure planning permission for a 13–turbine wind farm in the Múscraí Gaeltacht in Counties Cork and Kerry. The permission was granted by An Coimisiún Pleanála (formerly An Bord Pleanála) under the Strategic Infrastructure Development (SID) procedure.

The case sits at the intersection of three sensitive areas:

• the protection and promotion of the Irish language, particularly in Gaeltacht areas;
• rigorous application of EU environmental law (Habitats and Birds Directives, EIA Directive); and
• the urgent policy and legal imperative to facilitate renewable energy in the context of the climate emergency.

The judicial review was modularised. This judgment (Module I) deals with:

• Irish-language and constitutional issues (Core Ground 1 and the related constitutional attack in Core Ground 6);
• EU environmental law issues concerning Appropriate Assessment (AA) and conservation objectives/measures (Core Grounds 3 and 5);
• certain EIA complaints (Core Ground 4); and
• important procedural and evidential questions: pleadings, late evidence, burden of proof, harmless error and judicial discretion.

Only a narrow declaratory relief was ultimately granted (by consent) against the State. All operative challenges to the planning permission failed in Module I. A residual issue (the so‑called “Power/Knocknamona” point concerning the legal effect of missing site-specific conservation objectives in AA) is reserved for a later module once the Court of Justice of the EU (CJEU) answers questions referred in related proceedings.

2. Summary of the Judgment

2.1 Outcome

The court made the following key orders:

1. Declaration against the State: By consent, a declaration that, contrary to their EU law obligations, the second and third respondents (the State respondents) had failed to have site-specific conservation objectives (SSCOs) in place for The Gearagh SPA until 25 April 2025 (including at the time of the impugned decision).
2. All other Module I grounds dismissed:
   • Core Ground 1 (Irish-language / Article 8 challenge to the planning order) – dismissed.
   • Core Ground 2 (oral hearing) – not pursued.
   • Core Ground 3 (AA defects) – dismissed in part; remaining portion concerning the “Power issue” adjourned to the later module.
   • Core Ground 4 (EIA defects) – mostly abandoned; remaining point dismissed.
   • Core Ground 5 (general challenge to conservation objectives and measures) – dismissed beyond the limited declaration noted above.
   • Core Ground 6 (constitutional invalidity of s.20(3) of the Official Languages (Amendment) Act 2021 and SI 692/2024) – dismissed as academic.
3. Costs: Costs were largely reserved. The applicant’s costs on Core Ground 5 up to the State’s Statement of Opposition (insofar as they relate to the conceded declaration) are reserved; otherwise no order for costs in Module I as against the applicant, and opposing parties’ costs otherwise reserved.

2.2 Central holdings

The judgment makes (or consolidates) several important points of principle:

• Irish-language obligations in planning decisions:
  • The former statutory “Language Scheme” of An Bord Pleanála lost legal force when its enabling provisions in the Official Languages Act 2003 were repealed by the 2021 Amendment Act.
  • Article 8 of the Constitution does not oblige An Coimisiún Pleanála to issue planning orders bilingually, even for Gaeltacht developments where Irish submissions were made.
  • Section 9(3) of the Official Languages Act 2003 (communications “for furnishing information or marketing”) does not extend to the legal text of a planning order.
  • Issuing the order initially in English only, and later in Irish following an oversight, was at most a harmless error and did not warrant certiorari.
  • A challenge to the repealing legislation (s.20(3) 2021 Act and SI 692/2024) was academic because, even assuming unconstitutionality, no remedy against the planning decision would follow.
• EU nature protection law and conservation objectives/measures:
  • The absence of SSCOs for Gearagh SPA constituted a breach of EU obligations by the State, justifying declaratory relief; but it did not, on the evidence and arguments advanced, invalidate the Board’s AA or its permission.
  • Non‑qualifying species (Merlin, Golden Plover) only trigger obligations under the Birds Directive if “present in a significant manner” at the SPA (following the CJEU’s Elliniki judgment). The applicant failed to prove such significance.
  • Conservation measures were in fact in place; the applicant had pleaded a bare absence but did not displace the detailed factual evidence given by the State.
• Appropriate Assessment and EIA:
  • The Board’s AA for Hen Harrier and other species at Mullaghanish to Musheramore Mountains SPA and The Gearagh SPA was adequate on the material before it; the applicant did not adduce timely expert evidence showing any scientific deficiencies or “reasonable doubt”.
  • There is no general autonomous obligation on a decision-maker to keep abreast in real time of every new technical guidance document (such as updated NatureScot collision‑risk guidelines) absent evidence that such documents have become a widely-accepted new scientific standard.
  • The EIA in respect of White‑Tailed Eagle and landslide risk was adequate; the remaining complaint about the relocation of turbine T7 failed both on pleading and on substance.
• Procedural and evidential rules in judicial review:
  • The “eight‑fold path” to judicial review relief (articulated in Reilly v An Coimisiún Pleanála) is reaffirmed and applied.
  • Pleadings must be precise and self‑contained; applicants cannot expand their case via submissions or late affidavits.
  • Ex post facto expert evidence filed as “reply” (the Heffernan affidavit) was inadmissible; evidence must be substantially in place at leave/early affidavit stage.
  • The burden of proof lies on the applicant to show AA/EIA defects, usually by timely expert evidence or by exposing patent flaws on the face of the record.
  • The harmless error doctrine and judicial discretion have real bite: technical errors that make no material difference to outcome do not justify certiorari, including in the EU environmental law sphere.
  • The climate emergency and the strong legal framework favouring renewable energy are relevant factors in the exercise of discretion.

3. Background and Procedural Context

3.1 The project

The project is a strategic infrastructure wind farm comprising 13 turbines (after omission of T12 by condition), substation and associated works spread across townlands in County Cork and County Kerry, substantially within the Múscraí Gaeltacht. The application was made directly to An Coimisiún Pleanála under s.37E of the Planning and Development Act 2000 (the PDA) following pre‑application consultation under s.37B, where the development was designated as SID.

The application was accompanied by:

• an Environmental Impact Assessment Report (EIAR);
• a Screening for Appropriate Assessment and a Natura Impact Statement (NIS);
• reports from prescribed bodies including NPWS (via DAU), Geological Survey, IAA, Inland Fisheries, Uisce Éireann, TII; and
• two detailed internal reports: an Ecologist’s report and an Environmental Scientist’s report to the Board.

The Board requested further information (RFI) in July 2023. Having received the response in September 2023, it considered that no new significant information arose requiring further public consultation. The Inspector recommended granting permission, omitting T12. The Board’s decision of 25 February 2025 followed that recommendation.

3.2 The applicant and grounds of challenge

Wild Ireland Defence CLG participated in the process, making bilingual submissions (Irish and English) and requesting an oral hearing. It then brought judicial review under s.50 PDA and s.3 of the Environmental (Miscellaneous Provisions) Act 2011, advancing six “Core Grounds” (plus reliefs). By the hearing of Module I:

• Core Ground 2 (oral hearing) and much of Core Ground 4 (EIA – eagle and landslide points) were abandoned.
• The remaining grounds raised:
  • Core Ground 1: invalidity of the decision for being issued only in English, contrary to Article 8 and the Board’s Irish-language practice and scheme.
  • Core Ground 3: allegedly defective AA in respect of Mullaghanish to Musheramore Mountains SPA and The Gearagh SPA, especially Hen Harrier, Merlin, Golden Plover.
  • Core Ground 4 (residual): alleged EIA shortcomings in relation to the movement of T7.
  • Core Ground 5: alleged failure by the State to establish adequate site-specific conservation objectives and conservation measures for Gearagh SPA and Mullaghanish to Musheramore Mountains SPA, including obligations arising from the CJEU’s Elliniki judgment.
  • Core Ground 6: constitutional invalidity of the repeal of the language scheme provisions in the Official Languages Act 2003 by the 2021 Act and its commencement SI.

3.3 Modularisation and the “Power/Knocknamona” issue

The proceedings were modularised. Module I concerned the Irish language issues, the “Power and validity” aspects of AA arising from missing SSCOs, and related EU law issues affecting the validity of the Board’s decision. A separate module was reserved for the more general question whether a Board can lawfully carry out AA in the absence of SSCOs – an issue already referred to the CJEU by the Court of Appeal in Knocknamona (Case C‑27/25), and also engaged in Massey (Case C‑356/25).

4. Analysis of the Judgment

4.1 Irish Language, Article 8 and the Effect of Repealing Language Schemes

4.1.1 Factual and legal context

Historically, An Bord Pleanála operated a formal “Language Scheme” under the Official Languages Act 2003. The 2021–2024 Scheme included a policy to issue bilingual Board orders:

• where an application or appeal in a Gaeltacht area was made in Irish; and
• as a matter of practice, for significant developments in Gaeltacht areas even without Irish submissions.

In this case, the applicant’s submission was bilingual, the EIAR non‑technical summary was available in Irish, and the development lay substantially in the Múscraí Gaeltacht. Nonetheless, the Board’s order of 25 February 2025 issued in English only. An Irish translation was later published on 9 July 2025, with notification to the parties.

The applicant argued that:

• Article 8 of the Constitution, making Irish the first official language, required a bilingual order, at least in these circumstances;
• the Board’s language scheme (para. 3.1(i)) committed it to issuing bilingual orders in such Gaeltacht cases;
• repeal of the statutory basis for language schemes by s.17 of the Official Languages (Amendment) Act 2021, commenced on 21 December 2024 by SI 692/2024, without putting substitute “language standards” in place, was itself unconstitutional and invalid;
• section 9(3) of the (amended) 2003 Act obliged the Board to communicate its decision in Irish (or bilingual) to those who participated in the process.

4.1.2 The court’s treatment of the Board’s language scheme

A key doctrinal innovation in this judgment is the clear holding that a statutory language scheme has no continuing legal force once its enabling provisions are repealed.

Humphreys J reasoned that:

• Language schemes are “statutory measures”. When the legislative power under which they are made is repealed, they cannot survive in force unless express transitional/saving provisions say otherwise.
• The idea that a scheme can perpetuate its own legal force by declaring that it remains in force until replaced, regardless of repeal of the enabling power, is legally “frivolous and unstateable”. A subordinate instrument cannot override the Oireachtas’s decision to repeal its statutory basis.
• Therefore, after the 2021 Act repealed the language scheme provisions, the Board’s scheme had at most policy status, not binding legal effect.

This is a significant clarification for all public bodies that had language schemes: repeal of the scheme regime does not leave them labouring under surviving quasi-statutory obligations; what remains is policy and practice, subject to public law principles but lacking hard-edged justiciable duties.

4.1.3 Article 8 and the absence of a bilingual order

On the constitutional claim, the court held that Article 8 does not impose a requirement that an administrative decision such as a planning permission be issued bilingually, even where:

• the development is in the Gaeltacht, and
• submissions have been made through Irish.

Humphreys J stressed:

• No specific statutory or constitutional provision was identified that mandated issuing the order in Irish, or in both languages, on pain of invalidity.
• The applicant’s own reliance on Ó Beoláin, Ó Maicín and Glann Mór Céibh did not assist: those authorities recognise language rights and obligations, but they do not create a free‑standing duty to issue all (or all Gaeltacht‑related) administrative decisions bilingually.
• Given that even primary legislation is not unconstitutional merely because the Irish‑language version is not simultaneously available, it is “beyond implausible” to argue that a delay in issuing an Irish translation of a planning order is unconstitutional.

He also noted features undermining the claimed prejudice:

• The applicant’s pleadings and legal submissions on the language issue were entirely in English.
• The delayed Irish translation did not prevent or impede the lodging of judicial review within time.
• No tangible harm to participation, comprehension or rights was shown; the ground was “formalistic and abstract”, a “technical gotcha point” rather than a substantive rights violation.

4.1.4 Section 9(3) Official Languages Act 2003

Section 9(3) requires public bodies, where communicating “with the general public or a class of the general public for the purpose of furnishing information … or for the purpose of the marketing of the public body or its services”, to ensure such communication is in Irish or bilingual.

The court held this provision does not extend to the legal text of a planning order itself. It is directed at information or promotional communications, not the core instrument of decision-making. Hence, it provided no pathway to invalidating the permission.

4.1.5 Harmless error and judicial discretion in language cases

Even if there had been a legal breach (which the court decisively rejected), Humphreys J would have refused certiorari:

• The error, if any, was minor, technical and temporary – a simple oversight later corrected.
• It had no impact on the substance of the decision, the reasoning, the AA/EIA, or the applicant’s ability to litigate.
• No prejudice to the applicant or other parties was demonstrated.
• The Board had clear bilingual policies and practices and took prompt steps to rectify once the omission was realised.

He therefore categorised any lapse as a harmless error and invoked judicial discretion to refuse relief. Importantly, he brings the climate context explicitly into the discretionary analysis:

• The court reminded that there is an urgent climate emergency, with a dense body of international, EU and domestic law (UNFCCC, Paris Agreement, EU Climate Law, Irish Climate Action legislation, carbon budgets, Renewable Energy Directives, EU Regulation 2022/2577) mandating rapid expansion of renewable energy.
• Quashing critical renewable infrastructure on purely technical, formalistic grounds would be disproportionate and “improvident” in that context.

Thus, the case sets a pragmatic precedent: language oversights, absent real prejudice, will not derail major renewable energy projects via judicial review, even in Gaeltacht settings, provided the error is corrected and the overall language regime is functioning.

4.1.6 Academic constitutional challenge and standing

Core Ground 6 argued that the repeal of language schemes and commencement of s.17 of the 2021 Act were unconstitutional and invalid because alternative protective mechanisms (language standards) were not yet operational, allegedly weakening language protection for Gaeltacht communities.

The court treated this as impermissibly abstract and academic:

• The applicant’s standing derived from its participation in a concrete planning process culminating in a specific permission.
• Even if the repeal provisions were unconstitutional and the Board’s language scheme somehow remained in force, the scheme was in substance complied with (via later translation) and any temporary non‑compliance would still not warrant certiorari for the reasons already given.
• Accordingly, the constitutional question could not affect the validity of the permission; deciding it would be advisory or abstract, contrary to well‑established Irish jurisprudence on locus standi (Nawaz, McGreal, etc.).

This reinforces the principle that constitutional challenges to general measures must be anchored in a live, outcome‑determinative controversy. They cannot be used to litigate systemic language policy divorced from a concrete remedy.

4.2 Conservation Objectives, Conservation Measures and AA: Core Grounds 3 & 5

4.2.1 Key EU law framework

The case engages core provisions of EU nature law:

• Habitats Directive – Article 6(1) and 6(2) (conservation measures, avoiding deterioration), and Article 6(3) (Appropriate Assessment for plans/projects likely to affect a site).
• Birds Directive – Article 3 (general habitat protection duty), Article 4(1)–(2) (designation and protection of SPAs for Annex I and other migratory species).
• National transposition – in particular Regulation 26 of SI 477/2011, and ss.177U–177V PDA 2000.

Two Natura 2000 sites are central:

• Mullaghanish to Musheramore Mountains SPA – designated for Hen Harrier, with site-specific conservation objectives (SSCOs) since 2022.
• The Gearagh SPA – a complex wetland system; SSCOs were only formally published on 25 April 2025 (i.e. after the planning decision).

The applicant alleged:

• the State failed to have proper SSCOs and conservation measures in place, particularly for The Gearagh; and
• the Board’s AA was consequently flawed, both for Qualifying Interest (QI) species (Hen Harrier, waterbirds) and for non‑QI species (Golden Plover, Merlin) that allegedly should have been treated as protected “additional species” under the Birds Directive.

4.2.2 State concession on Gearagh SSCOs and declaratory relief

The State respondents conceded that, at the time of the Board’s decision, there were no SSCOs formally published for The Gearagh SPA. They accepted a declaration that this was contrary to their obligations under EU law.

However, SSCOs were in fact published on 25 April 2025, shortly afterwards. The key question was whether the absence of SSCOs at the moment of decision invalidated the planning permission.

Humphreys J refused to take that step:

• The applicant did not demonstrate, with evidence, that the missing SSCOs caused any substantive flaw in the AA or changed the ecological conclusions.
• As in Carrownagowan and Massey, there is no automatic rule that the absence of SSCOs invalidates AA; the court must examine materiality/harmlessness.
• Applying the burden of proof, the applicant failed to move beyond assertion to show any actual inadequacy or gap in the AA attributable to missing SSCOs.

Thus, the declaration stands as a formal acknowledgement of State non‑compliance with EU obligations, but without knock‑on invalidity for the Board’s decision.

4.2.3 Conservation measures: factual existence and pleading

The applicant pleaded, in broad terms, that the State had failed to establish necessary conservation measures for The Gearagh SPA and Mullaghanish to Musheramore Mountains SPA. The State, via detailed affidavit from Ciara Carberry, set out a raft of specific existing measures – some formal, some operational – relating to these SPAs.

Critically:

• The applicant did not plead a requirement that conservation measures must be contained in a discrete, standalone, published document of a particular kind.
• Its case, on the pleadings, was simply that there were no such measures.
• Once the State produced cogent evidence of measures, the onus shifted back to the applicant to rebut that evidence; it did not do so.

Accordingly, the allegation of an “absence” of conservation measures collapsed on an evidential basis. The judgment stresses that technical arguments about the adequacy or format of measures must be firmly rooted in precise pleadings and supported by expert evidence; they cannot be built on bare, disproved assertions.

4.2.4 Non‑qualifying species and the CJEU’s Elliniki judgment

A more subtle aspect of the case relates to two non‑qualifying species:

• Merlin at Mullaghanish to Musheramore Mountains SPA; and
• Golden Plover at The Gearagh SPA.

Relying on the CJEU’s decision in Elliniki Ornithologiki Etaireia (C‑66/23, 12 September 2024), the applicant argued that these species are Annex I or otherwise protected migratory birds, regularly present in the SPAs, and therefore should have:

• specific conservation objectives and measures, and
• featured in the AA as additional “conservation interests”.

Elliniki held that conservation objectives of an SPA must take account not only of the “classification species” (QI species) but also of other bird species protected under the Birds Directive that are present in a significant manner in the site.

Humphreys J accepted that principle but highlighted the crucial qualifier: significant presence. He drew on the Advocate General’s analysis, which, using the Natura 2000 data forms, associates “significant” with higher abundance categories (e.g. A, B, C), not mere occasional or very rare occurrence.

On the facts:

• The State’s evidence (from an NPWS official) was that Merlin and Golden Plover were not present at these SPAs in a manner requiring designation as additional protected species.
• The applicant produced no admissible, timely expert evidence to demonstrate the contrary – for example, population data, survey evidence or any systematic showing of significant presence.

Since the burden of proof lay with the applicant, the court held that:

• there was no proven obligation to create separate objectives/measures for Merlin or Golden Plover; and
• the Board’s AA could not be faulted for not treating them as QI‑equivalent species.

This application of Elliniki is important: it confirms that the decision does not create an automatic requirement to add any “regularly occurring” protected bird to the list of QI species. There must be evidence of significant presence, and that evidence must be brought to the court in a timely way if it is to underpin a judicial review.

4.2.5 Hen Harrier at Mullaghanish to Musheramore Mountains SPA

For Hen Harrier (a QI species for Mullaghanish), the applicant’s central complaint was that the Board did not “expressly consider” the SSCOs or apply up‑to‑date collision risk methodologies, including more recent NatureScot guidance.

The court’s response had two strands:

1. Consideration of SSCOs:
   • The inspector’s report set out a detailed assessment of the SPA and its objectives, including direct reference to the NPWS website and documentation.
   • The absence of an explicit narrative cross‑reference to the SSCO document did not prove it was not considered. Irish administrative law does not equate “no express mention” with “no consideration”.
   • The applicant failed to provide evidence that a reasonable expert, reading the AA and supporting reports as a whole, would detect any lacuna or unresolved scientific doubt.
2. Collision risk and evolving technical guidance:
   • The EIAR’s collision modelling relied on 2017 NatureScot guidance. Newer guidance emerged in 2024.
   • The court emphasised the principle of workability: decision‑makers cannot be subject to a continuous, open‑ended duty to monitor and autonomously evaluate all new technical publications worldwide, particularly from non‑EU, sub‑national authorities.
   • Only where new guidance attains widespread recognition as a “new standard” might there be an obligation to take account of it. No evidence was adduced to establish that status for the 2024 NatureScot guidance.
   • The burden lay on the applicant to demonstrate that the Board’s reliance on 2017 guidance was scientifically deficient; that burden was not discharged.

In short, the AA for Hen Harrier was upheld as lawful and scientifically adequate on the material before the Board at the time.

4.2.6 Alleged failure to seek further submissions (NPWS/DAU)

The applicant criticised the Board for not re‑consulting NPWS/DAU on the RFI response. The court noted:

• No statutory obligation to re‑consult was identified.
• The NPWS itself did not complain of being denied an opportunity to comment further.
• The applicant, as a third-party, cannot rely on NPWS’s participation rights – that would offend the ius tertii rule (asserting another’s rights).
• Recent CJEU case law (Asociación Petón do Lobo C‑461/24) underlines that public participation is not an endless loop; there is no right to comment on comments.

The complaint therefore disclosed no legal defect in the AA or decision-making process.

4.3 EIA Complaints and Turbine T7 (Core Ground 4)

Most of Core Ground 4 was abandoned (White‑Tailed Eagle, landslide risks). The remaining live point related to condition 4(b), which required turbine T7 to be shifted slightly south to avoid impinging on a local road.

The applicant suggested this meant the “whole project” had not been made subject to prior EIA, contrary to Articles 2–3 of the EIA Directive. Humphreys J rejected this:

• The pleading was vague and lacked a “route‑map” from alleged legal error to the relief of certiorari; this fell foul of Order 84 r.20(3) RSC (precision in grounds).
• Substantively, the inspector had assessed the project including the proposal for T7; the subsequent minor adjustment to ensure compliance with road safety and engineering constraints fell within normal planning conditioning practice.
• Condition 4(b) required submission of revised drawings and agreement with the planning authority; this provided appropriate scrutiny of any changes, and any resulting decision would itself be amenable to judicial review.

The court viewed the T7 complaint as merit‑based quibbling rather than a genuine EIA law defect; it failed on pleading, on evidence and on substance.

4.4 Procedural and Evidential Principles Reaffirmed and Applied

4.4.1 The “eight‑fold path” to judicial review

A particularly useful aspect of the judgment is its restatement of what Humphreys J (following Reilly v An Coimisiún Pleanála) calls the “eight‑fold path” – eight cumulative conditions for granting judicial review relief:

1. Jurisdictional compliance (time limits, standing to bring the proceedings).
2. Legal correctness and workability of the point (no relief on the basis of unworkable interpretations).
3. Proper pleading with requisite specificity.
4. Standing to raise each specific point (including ius tertii limitations).
5. Material before the decision‑maker must have triggered a duty to consider the point (subject to limited exceptions).
6. Onus of proof – the applicant must establish all facts necessary for relief.
7. Error must be material – must go beyond harmless/technical, with real‑world consequences.
8. Discretion – relief must be appropriate, proportionate and not futile.

The court’s analysis of each contested ground is explicitly structured through this lens. Notably:

• Core Ground 4 failed both at (3) (pleading) and, even assuming a plausible legal point, at (6)–(8) (no evidential foundation, harmless error and discretion).
• The Irish-language challenge failed at multiple stages: (2) (no workable legal rule requiring bilingual orders), (3) (no pleaded route-map from breach to invalidity), (6) (no prejudice) and (7)–(8) (harmless error/discretion).

4.4.2 Pleadings: precision and limits on expansion

The judgment strongly reinforces existing Court of Appeal and Supreme Court jurisprudence on strict pleading requirements in judicial review. Key points include:

• Order 84 r.20(3) RSC requires precise statement of each ground, with particulars and identification of supporting facts; general or abstract assertions are insufficient.
• Applicants are confined to their pleadings; they cannot, via written submissions, turn a loosely-drafted ground into a far broader challenge (e.g. an unpleaded precautionary principle argument).
• “Scattergun” pleadings, reciting high‑level principles without mapping them onto the concrete facts and impugned decision, are discouraged (citing Hellfire Massy, Ballyboden Tidy Towns).
• While courts may sometimes grant unpleaded relief within the contours of the pleaded case, they may not entertain entirely new grounds that appear only in submissions.

In practice, this meant:

• Core Ground 4’s residual T7 argument was found too vague and formless to justify relief.
• The applicant’s attempt to rely on the precautionary principle (only raised in submissions) was disregarded.

4.4.3 Late expert evidence and “reply” affidavits

The affidavit of Marie Louise Heffernan, an ecologist, was filed very late – nearly six months after proceedings commenced and three weeks before the hearing. It purported to “reply” to the Board’s and developer’s expert material by critiquing the EIAR, NIS and ecological assessments.

The court held this affidavit inadmissible (or of no weight) because:

• It was not a true reply; it introduced substantial new expert criticisms that could, and should, have been put forward at leave stage or in the first applicant affidavit.
• Applicants must “marshal” their evidence before opposition papers are filed; there is no open‑ended entitlement to drip‑feed new evidence whenever an opponent exposes a gap in their case.
• Permitting such practice would create procedural chaos, prejudice respondents and undermine case‑management.
• Much of the affidavit consisted of ex post facto argumentation and commentary on the merits of the ecological assessment, which is generally inadmissible in affidavit form.

The decision builds on other recent cases (Oxigen Environmental, Kennedy, Fahybeg) and sends a clear message: in environmental judicial review, applicants must front‑load their expert evidence. “Reply” affidavits cannot be used to reconstruct or enlarge the case at the eleventh hour.

4.4.4 Burden of proof and “lens of the material”

Humphreys J reiterates two linked principles:

1. Lens of the material before the decision‑maker:
   • Legality is assessed primarily on the basis of the material before the decision‑maker at the time of decision.
   • New evidence is generally inadmissible save in defined exceptions (e.g. where the authority had an autonomous duty to consider a matter but failed to gather the necessary information).
   • If the applicant did not raise a point during the administrative process, and the decision‑maker had no autonomous obligation to consider it, it is usually too late to rely on it in judicial review.
2. Burden of proof on the applicant:
   • In AA/EIA challenges, the applicant must prove defects – either by showing patent errors on the face of the record or by adducing expert evidence that demonstrates scientific shortcomings or unresolved “reasonable doubt”.
   • Mere assertions, suspicions, or disagreement with the decision-maker’s evaluative judgments are insufficient.
   • If there is a conflict of expert evidence and no cross‑examination, the conflict is ordinarily resolved against the party with the onus of proof (normally the applicant).

Applying this here:

• The applicant failed to demonstrate scientifically that Hen Harrier, Merlin or Golden Plover were inadequately assessed or that new guidance invalidated previous modelling.
• It failed to prove that “other plans or projects” in‑combination effects were neglected, or that conservation measures/mechanisms were lacking or inadequate as a matter of evidence.

4.4.5 Harmless error and discretion in EU environmental cases

The judgment provides a robust and practical reaffirmation of the harmless error doctrine, even where EU environmental directives are engaged:

• Citing Altrip and Irish determinations in Carrownagowan, Massey, the court notes that not every defect, even if established, compels nullification of a decision.
• The court may rely on evidence (including from developers) to conclude that the decision would have been the same even without the error.
• The test is whether there is any reasonable possibility that the error might have changed the outcome, not whether one can imagine any conceivable, remote theoretical scenario.

While AA must remove “reasonable scientific doubt” as to adverse effects on site integrity, that does not equate to absolute certainty or to erasing every hypothetical risk. Similarly, EIA must be “as complete as possible”, but not “impossibly onerous or unworkable”.

In this case, the court treats:

• the absence of SSCOs at The Gearagh SPA; and
• the late publication of the Irish translation of the planning order

as errors (or arguable errors) that did not pass the threshold of materiality. When combined with the climate imperative and the manifest public interest in renewable infrastructure, the balance of judicial discretion firmly favoured refusing to quash.

5. Complex Concepts Simplified

5.1 Appropriate Assessment (AA)

AA is a specific EU law procedure (Article 6(3) Habitats Directive) required where a plan or project is likely to have a significant effect on a Natura 2000 site. It involves:

1. Identifying the potential effects on the conservation objectives of the site.
2. Using best scientific knowledge and data.
3. Reaching a conclusion that there will or will not be an adverse effect on the integrity of the site.
4. Only approving the project if no such adverse effect is found (unless very strict Article 6(4) “derogation” tests are met, not in issue here).

The standard is that the assessment must remove “all reasonable scientific doubt” but need not reach absolute perfection or certainty.

5.2 Environmental Impact Assessment (EIA)

EIA (under Directive 2011/92/EU as amended by 2014/52/EU) is a broader procedure for major projects. It requires:

• An EIAR identifying, describing and assessing likely significant effects on the environment (population, biodiversity, land, water, air, climate, cultural heritage, etc.).
• Public participation in the assessment process.
• A reasoned conclusion by the competent authority on the significant effects.

The assessment must be as complete as reasonably possible, but again not “impossibly onerous”. Some residual uncertainty is acceptable.

5.3 Site-Specific Conservation Objectives (SSCOs) vs Conservation Measures

• SSCOs are precise statements of what is to be maintained or restored in a Natura 2000 site (e.g. population levels, habitat area, structure and function for each QI species or habitat).
• Conservation measures are concrete actions or regimes (e.g. restrictions, management plans, restoration works) adopted by the State to achieve those objectives.

While SSCOs greatly facilitate AA (by making it clear what integrity involves), their absence does not automatically mean AA is impossible or invalid. Courts now routinely ask: has the missing objectives actually led to a deficient AA in substance?

5.4 Qualifying Interest (QI) vs Non‑Qualifying Species

• QI species are those formally listed in the designation of an SPA or SAC as reasons for protection.
• Non‑QI species may nonetheless be protected under the Birds or Habitats Directives and may have to be considered if they are present in a significant way in the site.

Following Elliniki, SSCOs must, where relevant, encompass such significant non‑QI species. But a sporadic or negligible presence does not trigger this obligation.

5.5 Gaeltacht and Official Languages Regime

• The Gaeltacht comprises areas where Irish is the traditional community language. State policy and law give them special recognition.
• The Official Languages Act 2003 originally required public bodies to adopt “Language Schemes” setting out how they would provide services in Irish and English.
• The Official Languages (Amendment) Act 2021 shifted the model towards standardised language “standards” and repealed the scheme provisions; this repeal came into force by SI 692/2024.

This case clarifies that once the scheme provisions are repealed, any existing schemes lose their statutory force; they may persist only as non‑binding policy.

5.6 Harmless Error

“Harmless error” means a legal or procedural defect that, even if established, did not and could not reasonably have affected the outcome of the decision. Under both Irish and EU law:

• Courts should not quash decisions for harmless errors, especially where doing so would be disproportionate or futile.
• The burden lies on the party invoking harmlessness (usually the respondent/developer) once some error is shown.
• The court may rely on affidavits and the record to determine that the outcome would have been the same.

In this case, the late issuance of an Irish translation and the absence of SSCOs at a particular moment were found to be, in effect, harmless with respect to the permission.

6. Impact and Significance

6.1 Irish-language litigation and public bodies

The judgment is a cautionary note to litigants seeking to leverage language technicalities to quash decisions:

• Article 8’s recognition of Irish as the first official language does not morph into a guarantee that all or even all Gaeltacht‑related administrative decisions will be bilingual.
• Former language schemes no longer have binding legal force after repeal of the scheme regime; breaches of them cannot, without more, ground certiorari.
• Minor oversights in language practice, promptly corrected and causing no prejudice, will be treated as harmless error – particularly where the stakes are high (e.g. climate‑critical infrastructure).

For public bodies, the decision:

• removes uncertainty about the status of old language schemes post‑repeal;
• encourages continued robust bilingual practice, especially in Gaeltacht matters, while providing reassurance that honest mistakes are not fatal; and
• underscores the importance of quickly rectifying any language oversights and documenting bilingual policies and practice.

6.2 Environmental NGOs and community objectors

For environmental litigants, the judgment carries several messages:

• Challenges must be tightly pleaded and backed by early, independent expert evidence; the court will not “fill in the gaps”.
• AA/EIA arguments based on missing SSCOs, alleged lack of conservation measures, or treatment of non‑QI species must be fully evidenced with population data, survey analysis, and a clear causal link to flaws in the Board’s reasoning.
• Reliance on the latest technical guidance (e.g. from NatureScot) must be accompanied by evidence that such guidance represents an accepted scientific standard at the relevant time.
• Courts are increasingly ready to apply harmless error and discretionary principles, even in EU environmental contexts, where defects are shown to be non‑material.

6.3 An Coimisiún Pleanála and NPWS

The decision supports:

• the lawfulness of the Board’s current AA/EIA practices, provided that:
  • they are rooted in up‑to‑date, defensible scientific reports; and
  • internal ecologists and scientists engage with both QI and relevant non‑QI species.
• NPWS’s approach to defining when a non‑QI species is “significantly present” for the purposes of Elliniki, while implying that clear, published criteria and data would help withstand future challenges.

At policy level, the declaration against the State regarding Gearagh SSCOs is a reminder that compliance with EU obligations on conservation objectives must be rigorous and timely – even if individual planning decisions may not always be vitiated by transitional gaps.

6.4 Climate emergency and planning law

Finally, the judgment explicitly weaves into Irish public law the global and European case law recognising climate obligations. By setting out in detail the international climate architecture, EU Climate Law, Irish Climate Acts, carbon budgets and Renewable Energy Directives, the court signals that:

• Renewable energy projects benefit from a strong legal presumption in favour of expeditious deployment.
• Judicial review must not be used as “politics by other means” to derail climate‑aligned infrastructure through technical quibbles.
• In exercising discretion, courts may legitimately consider the climate emergency and broader public interests alongside procedural imperfections.

This is likely to influence future planning judicial reviews involving energy and climate-related infrastructure.

7. Conclusion

Wild Ireland Defence CLG v An Coimisiún Pleanála is a dense, carefully structured judgment that advances Irish administrative, constitutional and EU environmental law along several fronts.

On the Irish-language front, it draws a clear line between legal obligations and policy practices, holding that the repeal of the language scheme regime extinguished the binding nature of the Board’s scheme, and that Article 8 does not confer a justiciable right to bilingual planning orders. Language oversights, absent prejudice, are folded into the harmless error and discretion doctrines rather than treated as automatic triggers for nullity.

On EU nature law, the court:

• acknowledges a State breach in failing to have timely SSCOs for The Gearagh SPA,
• but insists that invalidating a permission requires proof of substantive defects in AA/EIA causally linked to that breach, not a formalistic reliance on missing documents.
• It applies Elliniki in a measured way, limiting obligations toward non‑QI species to cases where their presence is shown to be significant.

Procedurally, the judgment is an important consolidation of:

• the eight‑fold test for judicial review;
• strict pleading rules;
• front‑loading of expert evidence;
• the lens‑of‑material principle; and
• the robust application of harmless error and judicial discretion, including in EU law contexts.

Ultimately, the case stands for a principled but pragmatic approach: courts will enforce language and environmental duties, and will grant declaratory relief where State obligations are breached, but they will not lightly set aside complex, climate‑critical planning decisions on technical or minor lapses that have no demonstrated material effect on outcomes. This strikes a deliberate balance between legal rigour, rights protection, and the pressing public interest in timely decarbonisation and environmental protection.