Notice Parties Cannot Obtain Pre‑Emptive Aarhus “Not Prohibitively Expensive” Costs Protection When Defending Conceded Planning JR Grounds

1) Introduction

Glaister and Ors v An Coimisiun Pleanala (Approved) [2026] IEHC 264 is a High Court costs decision arising within a planning judicial review challenging a grant of permission for a poultry development in Co. Mayo. The applicants had appealed the local authority’s grant of permission; the Commission ultimately granted permission contrary to its Inspector’s recommendation to refuse, principally due to Appropriate Assessment/European site concerns.

Before the substantive hearing, the Commission conceded two pleaded grounds (within Core Ground 3) alleging inadequate reasons for departing from the Inspector, in breach of section 34(10) of the Planning and Development Act 2000 (as amended). The developer (as notice party) nonetheless wished to defend those conceded grounds.

The developer sought, in substance, a pre-emptive protective costs order for the module hearing those conceded grounds—either: (i) confirmation of no order as to costs in advance; or (ii) a declaration that any adverse costs would be assessed on a “not prohibitively expensive” (NPE) basis under the Aarhus Convention/Irish implementing provisions.

2) Summary of the Judgment

  • The Court (Farrell J) accepted (as all active parties agreed) that the underlying planning judicial review fell within section 50B of the Planning and Development Act 2000, as interpreted by the Supreme Court in Heather Hill Management Company CLG v. An Bord Pleanála [2022] IESC 43, [2024] 2 IR 222.
  • The Court refused to make any pre-emptive order insulating the developer from costs risk. Whether a costs order might arise under section 50B(3) depends on how the proceedings are conducted and can only be assessed after the relevant module (or proceedings) concludes.
  • The Court held the Aarhus/NPE principle is directed to the party bringing environmental challenges, not a party defending an administrative decision (including where the decision-maker has conceded invalidity).
  • The notice party’s application for pre-emptive costs protection was refused. The Court proposed no order as to costs for the costs of this interlocutory application (subject to short written submissions if any party sought a different order).

3) Analysis

3.1 Precedents Cited

Ballyboden TTG v. An Bord Pleanála [2024] IESC 4

The Supreme Court confirmed a notice party need not satisfy any threshold test to defend judicial review proceedings where the respondent decision-maker concedes relief. Crucially, a concession does not remove the presumption of validity: the applicant still must persuade the court to grant relief. Farrell J relied on this to frame the developer’s entitlement to defend—while separating that entitlement from any entitlement to advance costs immunity.

Heather Hill Management Company CLG v. An Bord Pleanála [2022] IESC 43, [2024] 2 IR 222

Heather Hill established that section 50B costs protection applies broadly to grounds challenging planning decisions of the relevant kind, aligning domestic law with the Aarhus Convention. Farrell J treated Heather Hill as dispositive of the threshold question: section 50B governed the proceedings. However, the dispute in this case concerned how section 50B operates where a notice party seeks pre-emptive protection while defending conceded grounds.

Hunter v. Environmental Protection Agency [2013] IEHC 591

Hunter was cited for two points: (i) section 50B(2A) addresses pre-litigation acts/omissions; and (ii) adverse costs under section 50B(3) are in the nature of a penalty and do not require “moral turpitude”. Farrell J accepted that moral turpitude is not required, but stressed that it does not follow that a notice party becomes cost-liable merely because it loses a contested module.

Rafferty v. An Bord Pleanála [2025] IEHC 19

Rafferty illustrated that a developer notice party can, in appropriate circumstances, be exposed to costs under section 50B(2A) where its acts/omissions contributed to the error leading to relief. Farrell J distinguished Rafferty factually: here, the conceded wrong (inadequate reasons for departing from the Inspector) was the Commission’s alone, so section 50B(2A) could not found a costs order against the developer. Rafferty was also treated as not establishing that an unsuccessful defence of conceded grounds, without more, triggers section 50B(3)(b).

Southwood Park Residents Association v. An Bord Pleanála [2019] IEHC 504

Southwood Park was used to illustrate circumstances where a party’s stance in litigation was found unreasonable, contributing to unnecessary costs. Farrell J treated it as context-specific: it did not stand for a general rule that a defender of conceded grounds is automatically exposed to adverse costs.

EPUK Investments UK v. Environmental Protection Agency [2023] IEHC 138

Although section 50B did not apply on the facts in EPUK, Farrell J found Holland J’s obiter observations helpful: “conduct” in section 50B(3) should be read alongside the neighbouring categories (frivolous/vexatious and contempt), indicating a relatively high bar—conduct meriting significant judicial deprecation. Farrell J adopted this as consistent with her interpretation of section 50B(3)(b).

Doyle v. An Bord Pleanála (No. 2) [2025] IEHC 205

Doyle was referenced for the observation that Irish Aarhus-style costs protection is materially “imbalanced” in favour of applicants. Farrell J accepted the statutory asymmetry as a policy choice of the Oireachtas, but refused to extend Aarhus/NPE concepts beyond their proper scope.

North East Pylon Pressure Campaign Ltd v. An Bord Pleanála (No. 5) [2018] IEHC 622 and C-470/16 North East Pylon Pressure Campaign Ltd v. An Bord Pleanála ECLI:EU:C:2018:185

Farrell J relied on the CJEU decision for the meaning and purpose of the NPE requirement under Article 9 of the Aarhus Convention: it is designed to ensure effective access to justice for persons seeking to enforce environmental law. She rejected the developer’s attempt to use “NPE” as a shield for the defence of a decision already conceded unlawful by the decision-maker. She also treated the domestic “no order as to costs” approach (noted in (No. 5)) as not supporting a forward-looking immunity for a notice party.

3.2 Legal Reasoning

(a) The statutory architecture of section 50B

Farrell J analysed section 50B as establishing:

  • Default rule (s.50B(2)): each party (including any notice party) bears its own costs.
  • Qualified applicant benefit (s.50B(2A)): a successful applicant may recover appropriate costs from the respondent/notice party to the extent their acts/omissions contributed to the applicant obtaining relief.
  • Sanction-based departure (s.50B(3)): costs may be awarded against a party due to frivolous/vexatious claims, the manner of conducting proceedings, or contempt.
  • Exceptional public importance (s.50B(4)): costs may be awarded in special circumstances (not invoked here).

The developer accepted it could not recover costs, but sought to eliminate (or cap) exposure to adverse costs. The Court found that the statutory scheme does not provide for pre-emptive immunity. Instead, it contemplates a retrospective assessment, particularly under section 50B(3)(b), which is drafted in the past tense (“has conducted”).

(b) Why section 50B(2A) could not apply to the developer here

On the conceded grounds, the alleged illegality was inadequate reasoning by the Commission when departing from its Inspector. The Court found it was not suggested the developer contributed to that failure; therefore, even if the applicants succeeded on those grounds, section 50B(2A) could not found a costs order against the developer.

(c) Why section 50B(3)(b) could not be decided in advance

The only realistic route to costs against the developer was section 50B(3)(b) (“manner” of conducting proceedings). Farrell J held it is logically and legally impossible to determine now whether the developer’s future conduct will meet the standard for a section 50B(3)(b) order. The mere fact of defending conceded grounds (and losing) was not equated with culpable “conduct”. The Court also indicated that factors such as whether the litigation concerned settled law, whether the defence impeded efficient resolution, and whether costs were unnecessarily inflicted could become relevant—but only at the end.

(d) Aarhus/NPE does not protect the defender of a challenge

The central new clarification is the Court’s construction of Aarhus Article 9(2)–(4) and its domestic implementation: NPE is to prevent members of the public being deterred from bringing environmental law challenges. It does not create an entitlement for a beneficiary of a contested decision to defend it on an NPE basis, particularly where the defence is not itself a “challenge” seeking environmental compliance. The Court considered this consistent with the CJEU’s emphasis that extending NPE beyond the legislature’s intent would be impermissible.

(e) No pre-emptive costs order under EMPA or inherent jurisdiction

Although argued mainly under section 50B, Farrell J also rejected the attempt to obtain equivalent pre-emptive protection under the Environment (Miscellaneous Provisions) Act 2011 or the court’s inherent jurisdiction, for the same reasons: costs consequences are to be determined after the relevant conduct and outcomes are known.

3.3 Impact

(1) A practical rule for conceded-planning JR litigation

This decision gives concrete guidance for a recurring scenario after Ballyboden: where a decision-maker concedes a pleaded illegality but a developer notice party insists on defending, the notice party cannot obtain an advance ruling eliminating costs risk, nor can it claim the Aarhus/NPE principle to cap adverse costs exposure.

(2) A narrower understanding of “NPE” in Irish practice

The Court’s reasoning confines NPE to its access-to-justice purpose: facilitating challenges to environmental illegality. This is likely to be relied upon to resist attempts by respondents or notice parties to recast Aarhus as a general “costs moderation” principle for all participants.

(3) Section 50B(3)(b) remains fact-sensitive but not automatic

The decision also discourages any assumption that an unsuccessful defence of conceded points automatically equals sanctionable “conduct”. Future courts will likely focus on whether the defence unnecessarily prolonged proceedings or imposed avoidable cost burdens—rather than the fact of losing.

(4) Settlement incentives and litigation strategy

By refusing advance costs immunity, the judgment increases the financial uncertainty for a notice party choosing to defend after concession. That may encourage earlier, more realistic evaluation of whether the defence serves any legitimate forensic purpose (for example, where the legal issue is genuinely uncertain), and may reduce contested hearings on plainly conceded errors.

4) Complex Concepts Simplified

Notice party
A person or entity directly affected by the outcome (here, the developer who benefited from the permission) and entitled to participate in the judicial review.
Certiorari
A court order quashing an unlawful administrative decision (here, potentially quashing planning permission).
Section 50B “costs protection”
A statutory regime in certain environmental/planning cases where the default is each party bears its own costs, with limited departures—especially to protect challengers.
Section 50B(2A)
A provision allowing a successful challenger to recover costs from those whose acts/omissions caused or contributed to the unlawfulness that led to relief. It is not a general costs-shifting rule; it is causation-linked.
Section 50B(3)(b) (“conduct” costs)
A mechanism for adverse costs where a party’s manner of conducting the proceedings warrants it (a sanction-type departure from the default). The Court stressed this cannot be decided prospectively.
“Not prohibitively expensive” (NPE)
An Aarhus Convention requirement ensuring environmental law challenges are not priced out of reach by costs risk. Farrell J held it protects challengers, not those defending an impugned decision.
Modularisation
Splitting proceedings so a preliminary issue is determined first (here, the conceded “reasons” grounds), potentially narrowing what remains.

5) Conclusion

[2026] IEHC 264 clarifies that while a developer notice party may defend a planning permission even after the decision-maker concedes unlawfulness, the notice party cannot obtain a pre-emptive order guaranteeing “no costs” or importing Aarhus “not prohibitively expensive” protection to its defence. Any adverse costs exposure for a notice party will arise, if at all, only after the court can assess whether section 50B(3) is engaged by how the proceedings were conducted.