Old Plan Policies Survive during s.31 Draft Direction where they 'Correspond' to the New Plan; Court Sets Six-Factor Test for Declaratory Relief and Reaffirms Harmless-Error Discretion in Renewable Energy Consents

Save The South Leinster Way & Anor v An Coimisiún Pleanála & Ors [2025] IEHC 541 (High Court, Humphreys J., 15 October 2025)

Introduction

This judgment addresses three interlocking themes of practical importance in Irish planning and environmental judicial review:

How section 31(6) of the Planning and Development Act 2000 operates when the Minister issues a draft direction under section 31(3), particularly whether and how provisions of an old development plan remain in force after a new plan has come into effect.
Whether identified legal error requires the blunt remedy of certiorari in circumstances where the error is technical, the project advances critical climate and energy policy, and the outcome would have been the same.
When declaratory relief should be granted if certiorari is refused, with the Court offering a structured six-criterion framework.

The case concerns a strategic infrastructure development permission for a 21-turbine wind farm at Castlebanny, Co. Kilkenny. The applicants—Save the South Leinster Way and Tara Heavey—sought to quash the decision of An Bord Pleanála (now An Coimisiún Pleanála) dated 26 September 2022. Central to their challenge was a technical contention arising from the Minister’s intervention in the development plan process: whether, pending a final direction under section 31, parts of the 2014 County Development Plan continued to apply by virtue of section 31(6)(b).

The respondents were the Commission and the State (Minister for Housing, Local Government and Heritage, Ireland and the Attorney General), with Springfield Renewables Ltd. as notice party. Following a prior time-limit appeal (resolved in the applicants’ favour by the Supreme Court), the High Court modularised the case, heard Module I (core grounds 1, 2, 5, 6, 7 in part, and 8), and reserved the s.146A correction issue and certain habitats issues to later modules.

Summary of the Judgment

Section 31(6) interpretation: The Court held that where the Minister issues a section 31(3) draft direction disapplying new-plan provisions, section 31(6)(b) preserves, to the extent of “correspondence”, the relevant provisions of the old plan—even after the new plan has taken effect. The term “corresponding” relates to the provisions themselves (including geographic correspondence), not the policy rationale behind them.
No quashing on discretion: Despite finding that the Commission should have proceeded on the basis that a vestigial part of the 2014 plan continued in force, the Court refused certiorari. It characterised the error as highly technical and harmless in outcome, and concluded that quashing would be perverse given the climate emergency, the policy framework favouring renewable energy, and the Minister’s intervention intended to facilitate such projects.
Declaratory relief framework: The Court refused a declaration and, significantly, articulated a six-criterion practical framework governing when declarations should be granted if certiorari is refused.
Reasons ground fails: A “reasons” challenge premised on the Board having considered and then materially contravened the 2014 plan failed as hypothetical: the Board did not in fact claim to consider the 2014 plan in that way.
EIA and AA grounds fail: The environmental impact assessment and appropriate assessment challenges failed. The applicants did not discharge their onus; the record, including a detailed further information (RFI) response, supported the Board’s evaluative conclusions; and the applicants did not cross-examine the developer’s experts (RAS Medical principle). The Court described certain arguments as ultracrepidarianism (non-expert critique of expert evidence).
Orders: Module I grounds (1, 2, 5, 6, 7 insofar as it concerns Lesser Black-backed Gull, and 8) dismissed; costs reserved on a set-off basis; the s.146A condition-correction challenge and related time-extension, together with remaining habitats issues (awaiting CJEU in Case C-27/25, Knocknamona) to proceed as Modules II and III.

Analysis

1. The Precedents and Authorities Cited and How They Influenced the Decision

(a) Judicial review standards and reading decisions in the round

Sweeney v. Fahy, Meadows, State (Keegan), and UK authorities like Cart were invoked to emphasise legality not merits; courts do not substitute their judgment for that of the decision-maker. Evaluative planning judgments attract deference absent legal, procedural or factual error and are generally reviewed on an irrationality standard (see Sherwin; Graymount House Action Group).
A large suite of authorities stress reading decisions sensibly and holistically—avoiding micro-parsing, semantic nit-picking, and “reading as invalid if a valid reading is available” (e.g., M.R. (Bangladesh), Rostas, St. Margaret’s Recycling, Walsh v. Jones Lang LaSalle, O’Sullivan v. HSE).

(b) Pleading discipline

The Court drew on a long line of cases requiring precision in judicial review pleadings (Order 84 rule 20(3)), confining applicants to pleaded grounds: A.P. v. DPP, Khashaba, Casey, Concerned Residents of Treascon, Ballyboden Tidy Towns, Rushe, Sweetman (XV), Alen-Buckley. Attempts to advance unpleaded arguments (e.g., public consultation on the RFI; NatureScot guidance compliance) were impermissible.

(c) Onus of proof and expert evidence

RAS Medical was pivotal: where factual or expert issues are controverted by affidavit, failure to cross-examine is fatal. The Court repeatedly applied this to EIA/AA complaints, noting unchallenged expert affidavits from the notice party and characterising certain applicant assertions as ultracrepidarian.

(d) Harmless error and discretion

The Court relied on EU and domestic authorities endorsing a harmless-error approach where the outcome would not have been different (e.g., CJEU Altrip). It also referenced Save Cork City suggesting disproportionate to quash for “technical procedural error”, and reaffirmed that JR remedies are discretionary (O’Connell v. Behan; Westwood Club).
Ballyboden Tidy Towns (SC) confirmed the court’s entitlement to exercise discretion of its own motion—even if not pleaded by respondents.

(e) Climate and policy context

The Court situated the case within a dense climate law matrix: the Climate Act 2015 as amended (public body duties under ss.14B, 15), EU governance and climate law, Regulation 2022/2577 and Directive 2023/2413 establishing presumptions of “overriding public interest” and acceleration, and the ECHR judgment in KlimaSeniorinnen.

(f) Development plan/material contravention in SID

On SID applications, the Board may grant permission notwithstanding material contravention (s.37G(6)); no special “material contravention procedure” is required, and the Board may reason from “first principles” of proper planning and sustainable development (the Court referenced Ryanair DAC).

2. The Court’s Legal Reasoning

(i) Interpreting section 31(6): “corresponding” provisions continue

Section 31(6)(a) disapplies the new plan’s provisions referred to in the Minister’s section 31(3) notice. Section 31(6)(b) then preserves, save where section 31(17) applies (i.e., a final direction has issued), the “part of a plan proposed to be replaced” that “contains a matter that corresponds” to the matter referred to in the notice. This reading gives real work to paragraph (b). If the old plan necessarily ceased in toto upon the new plan taking effect (s.12(17)), paragraph (b) would be otiose—an interpretation the Court rejected.
“Corresponding” concerns the substantive content of the provision (and its geography), not the shifting policy rationale behind it. If the new and old provisions align in substance and area, the old provision “continues” for that area despite the new plan being “made,” until the section 31 process is concluded.
Applied here, both the 2014 plan and the adopted 2021 plan used a matrix disallowing large-scale wind farms in areas not designated “preferred”/“acceptable in principle.” For the overlapping geography at Castlebanny, the Court held there was correspondence and therefore survival of the 2014 “open for consideration” effects to that extent.

(ii) Why relief was refused despite an error

The Court carried out a principled discretionary analysis, concluding that quashing would be inappropriate:

The error was highly technical and arose in an interregnum between a draft direction and any final direction. The “vestigial” survival of part of an old plan in a technically complex statutory scheme did not speak to substantive planning harm.
No tangible environmental harm was pleaded or demonstrated from the error; the Inspector’s evaluation addressed proper planning concerns comprehensively; national and EU climate imperatives strongly favoured renewables.
The Minister’s intervention aimed to make the new plan more permissive for wind energy; quashing because of a collateral, not-consciously-intended technical consequence of that intervention would be “perverse” and bring the law into disrepute.
In the SID context, s.37G(6) allows grant notwithstanding material contravention. The Board’s decision proceeded from first principles of proper planning and sustainable development, consistent with the broader policy framework.
The harmless-error logic (what would have happened but for the error) is legitimate in EU and domestic law (CJEU Altrip); the Court expressly rejected the contention that separation of powers forbids asking whether the outcome would have differed absent the error.

(iii) A structured test for declaratory relief where certiorari is refused

The Court articulated a practical six-criterion guide for declarations:

(1) There must be a legal error.
(2) Certiorari or other imperative relief is being refused (declarations do not “labour in vain”).
(3) The declaration should relate to the specific error in the case—not to restating the law generally, which the judgment itself already does—thus avoiding orders that affect third parties who were not heard.
(4) Typically, the decision-maker should have denied the error prior to hearing; otherwise, a practice of “admit-error-but-argue-harmlessness” should not automatically attract declarations and costs.
(5) There should be a sufficiently affirmative public benefit in “marking” the error (e.g., repeated breaches; a serious point meriting formal censure).
(6) Overall discretionary factors must not militate against the grant.

Applying this framework, the Court refused a declaration: the point was technical; there was no public benefit in marking it; and the same discretionary factors that justified refusing certiorari applied to refusing a declaration.

(iv) Reasons: no hypothetical relief

The “reasons” complaint was framed in the alternative—if the Board had considered the 2014 plan and then materially contravened it. Since the Board did not claim to have considered the 2014 plan in that way, the ground was hypothetical and therefore non-justiciable under settled principle.

(v) EIA and AA: onus, RFI, and expert evidence

The EIAR and the developer’s RFI response contained detailed assessment, including clarifications on turbine dimensions (tip height, hub height, rotor diameter), noise, and collision risk modelling for birds. The Inspector recorded that the RFI did not materially alter the development and did not require further public participation.
Applicants did not adduce expert evidence to contradict the developer’s experts nor did they cross-examine. In such circumstances, and given the evaluative nature of EIA/AA (Holohan; Champion), the onus was not discharged. The Court rejected assertions premised on mismatched turbine configurations because the record addressed the maximum parameters and the modelling logic.

3. Likely Impact of the Judgment

(a) Development plan-making and decision-making during section 31 interventions

Planning authorities, the OPR, and the Commission must treat section 31(6)(b) as operative: where a section 31(3) notice disapplies parts of a new plan, corresponding provisions of the old plan continue to apply, to the extent of substantive and geographic correspondence, until a final direction issues (or the process otherwise concludes).
Decision-makers should explicitly identify the “corresponding” provisions and their spatial extent and explain how they were weighed. Mapping overlays (as the notice party produced) may become best practice.

(b) Remedies: a more structured and proportionate approach

The six-criterion guide for declaratory relief will likely reduce the incidence of “declaration-only” wins for technical errors, especially where respondents candidly accept error but show it to be harmless.
Harmless-error discretion is decisively affirmed in planning and environmental JR, particularly where quashing would thwart overarching statutory and EU policy objectives—here, renewable energy deployment during a climate emergency.

(c) Litigation strategy and evidential discipline

Applicants must bring expert evidence and be ready to cross-examine opposing experts; otherwise, EIA/AA criticisms couched as “scientific doubt” will be treated as ultracrepidarian and insufficient.
Unpleaded complaints (e.g., on RFI advertisement or technical guidance compliance) will not be entertained. The decision also underlines the judicial preference for reading a decision “in the round” rather than by micro-parsing.

(d) Climate policy mainstreamed into planning JR discretion

The judgment operationalises the climate emergency across the remedial stage: where the asserted error is technical and outcome-neutral, and the project serves urgent national/EU climate targets, the court is slow to quash.
Regulation (EU) 2022/2577 and Directive (EU) 2023/2413, establishing presumptions of overriding public interest and acceleration for renewables, now feature as salient background norms in Irish planning JR.

Complex Concepts Simplified

Section 31 “draft direction” and “corresponding provisions”: When the Minister issues a draft direction to disapply parts of a new plan, the old plan does not vanish in those areas. Instead, any part of the old plan that “corresponds” (matches in substance and geography) to the disapplied new provision continues in force until the Minister’s process concludes.
SID and material contravention (s.37G(6)): For strategic infrastructure development, the Commission can grant permission even if the proposal materially contravenes the development plan. No special contravention procedure applies; the Commission must still justify the decision by reference to proper planning and sustainable development.
Harmless error: Even if there is a legal mistake, courts won’t quash if, realistically, the outcome would have been the same. This requires the court to assess what would have happened but for the error; it does not offend separation of powers.
Declaratory relief (the six-criterion guide): Declarations are discretionary. They are not a consolation prize for every technical error. Courts will mark an error with a declaration only where that serves a concrete public value and where other equitable and discretionary considerations align.
Onus of proof and expert evidence in EIA/AA cases: Applicants must substantiate technical critiques with expert evidence. If the notice party puts in expert affidavits and they are not cross-examined, the court will ordinarily accept them.
Reading decisions “in the round”: Courts avoid ultra-literal, hyper-technical readings that convert minor infelicities or semantics into fatal errors. The key is whether, read as a whole, the decision demonstrates lawful reasoning and evaluation.

Key Precedents and Their Roles

Discretion and harmless error: CJEU Altrip; Save Cork City (strong dicta on proportionality of quashing for technical errors); O’Connell v. Behan; Westwood Club; Ballyboden Tidy Towns (discretion exercisable by court of its own motion).
Pleadings discipline: A.P. v. DPP; Casey; Concerned Residents of Treascon; Rushe; Sweetman (XV); Alen-Buckley; Order 84 r.20(3) RSC.
Onus/cross-examination: RAS Medical (failure to cross-examine is usually fatal to contested factual propositions).
Reading decisions in the round: M.R. (Bangladesh); Walsh; O’Sullivan v. HSE; St. Margaret’s Recycling.
EIA/AA standards: Holohan; Champion; C-50/09 (EIA completeness); principles about not disproving hypothetical risk and focusing on appreciable effects.
Climate framework and policy relevance: Climate Acts (2015/2021), Regulation 2018/1999, Regulation 2021/1119, Regulation 2022/2577, Directive 2023/2413, and ECtHR KlimaSeniorinnen.

Practical Guidance Emerging from the Case

When a section 31(3) notice issues, identify and map “corresponding” old-plan provisions for the affected geography and record in the planning assessment how they are considered.
Do not assume the section 31 process is self-executing to finality; in the interregnum, the old plan lives on to the extent of correspondence. Equally, do not treat the rationale shift between old and new plans as defeating correspondence.
In SID cases, remember s.37G(6): even if a plan provision bites, the Commission may lawfully grant permission on proper planning grounds.
For EIA/AA disputes, provide expert evidence and be prepared to cross-examine. Purely argumentative assertions or reliance on unaired methodological preferences will not suffice.
Consider the six factors before seeking declarations when certiorari is unlikely. The Court will not “mark” every error; a concrete public value is required.
Expect climate imperatives and EU acceleration measures for renewables to be salient in the court’s remedial discretion, especially where alleged errors are technical and outcome-neutral.

Conclusion

Humphreys J has delivered a judgment of real operational significance for both plan-makers and decision-makers. First, it provides clear guidance that section 31(6)(b) preserves the effect of “corresponding” provisions of the old development plan during a draft-direction interregnum, even after a new plan takes effect—importantly, “correspondence” is about substance and geography, not the mutable policy rationale. Second, the judgment robustly applies harmless-error and proportionality principles within a climate-policy frame, refusing to quash where the error is technical, outcome-neutral, and quashing would have the perverse effect of frustrating the very policy the Minister’s intervention was designed to advance. Third, the Court sets out a coherent six-criterion framework for declaratory relief in the absence of certiorari, which should help calibrate future remedies and moderate incentives for technical litigation.

The message to parties is clear: plead precisely; substantiate technical objections with expert evidence and cross-examination; read decisions sensibly; and expect the court to deploy discretion—grounded in climate and energy law imperatives—against drastic remedies where errors are minor, technical, and harmless in outcome. Meanwhile, authorities must carefully identify and reason through “corresponding” old-plan provisions whenever a section 31(3) notice disapplies new-plan policies, documenting spatial correspondence and its weight in the overall proper planning balance.

Finally, the Court has left open further modules on the section 146A correction of Condition 8 and on habitats issues pending the CJEU’s ruling in Knocknamona (C‑27/25). Those forthcoming determinations may yet add further contours to the law on administrative correction powers and appropriate assessment in the Irish planning system. For now, this judgment marks an important consolidation of statutory interpretation, remedial discretion, and climate-contextualised judicial review in the planning sphere.