Section 12(8)(b)(i) Planning Act: Listing a Submission’s Agent Suffices; Gillen Two‑Stage Invalidity/Discretion Test Confirmed in Planning JR

1. Introduction

In O'Donnell v Dublin City Council [2026] IESC 36, the Supreme Court (judgment delivered by Woulfe J.) allowed an appeal from the High Court and restored Dublin City Council’s adoption of the Dublin City Development Plan 2022–2028 insofar as it contained a material alteration rezoning the “Uniphar site” at Chapelizod.

The judicial review challenge arose from how the Council’s Chief Executive (“CE”) compiled the statutory report required by s. 12(8) of the Planning and Development Act 2000. The CE’s report included a list of “persons or bodies who made submissions” on proposed material alterations. The neighbouring landowner (a company operating an industrial business on adjacent lands) had opposed the rezoning via its planning consultant; the CE’s list named the consultant (“Doyle Kent Ltd”) rather than naming the company itself.

The core issues were (i) whether s. 12(8)(b)(i) required the CE to list the principal (the client) rather than an agent (the consultant), (ii) whether any such failure could ever be treated as de minimis / substantially compliant, and (iii) what general principles govern when breaches of planning procedures justify certiorari.

2. Summary of the Judgment

  • No breach: The Court held that s. 12(8)(b)(i) is complied with if the CE lists (a) the agent who lodged the submission, or (b) the principal, or (c) “agent on behalf of principal”. Listing the planning consultant alone therefore satisfied the statute.
  • Purpose of the list: The list’s primary function was characterised as administrative—a formal record of receipt/processing of submissions— rather than as an “alerting” tool enabling elected members to prioritise reading submissions by reference to the identity of the submitter.
  • De minimis / discretion principles: Although unnecessary to decide (given no breach), the Court addressed the certified questions and endorsed the two-stage approach in Gillen v Commissioner of An Garda Síochána [2012] 1 IR 574 for assessing consequences of non-compliance: first, interpret whether the legislature intended invalidity; if not, the court considers substantial compliance, de minimis, prejudice, and public interest in exercising its discretion whether to grant certiorari.
  • Hypothetical outcome: Even if listing the agent had been a breach, the Court indicated it would likely be trivial/technical with no demonstrated prejudice, i.e. a “harmless error”, and certiorari would have been refused.

3. Analysis

3.1 Precedents Cited (and How They Shaped the Decision)

(a) Statutory interpretation: Heather Hill as the starting point

The Court treated Heather Hill v. An Bord Pleanála [2022] IESC 43 as the controlling modern restatement of statutory interpretation: begin with the text’s ordinary meaning; read it in context (including the statutory scheme and practical setting); only then (if ambiguity remains) turn to purpose/mischief. Applying that approach, Woulfe J. reasoned that:

  • “persons … who made submissions” can literally include the person who did the operational act of lodging the submission (the agent);
  • because an agent acts with authority, the principal can also properly be said to have “made” the submission;
  • therefore identifying either (or both) is consistent with the statutory language when read naturally and contextually.

(b) Agent/principal naming: transposing Donegal County Council v. Quinn

A key move in the Court’s reasoning was to analogise to Donegal County Council v. Quinn [2025] IESC 19, where a summons had to “specify the name of the person who applied for the issue of the summons” under the Courts (No. 3) Act 1986. The Supreme Court there held a summons is valid if it names either the prosecutor or the solicitor-agent (or both). Woulfe J. adopted the same functional view of “who applied/made”: a statutory naming requirement can be satisfied by identifying either the operational actor (agent) or the authorising party (principal), absent clear legislative direction to insist on one only.

(c) “Workable interpretation” in large-scale planning exercises

The Court relied on the “workability” principle (citing Woulfe J.’s own discussion in Save Cork City Community Association CLG v. An Bord Pleanála [2024] 1 IR 205, and Hogan J.’s statement in Waltham Abbey v. An Bord Pleanála [2022] 2 ILRM 417) to interpret s. 12(8)(b)(i) in the practical reality of development plan making: high volumes of submissions and strict timeframes. Requiring the CE to “look behind” each named submitter to determine whether they were an agent (and then to identify the principal) was viewed as potentially imposing an additional burden and risking delay.

(d) Identity as a planning consideration: limiting the High Court’s reliance on “alerting elected members”

The High Court had treated the list as enabling elected members to identify constituents/employers and thereby find submissions of interest. The Supreme Court rejected that as a primary statutory purpose, invoking the planning law norm that planning decisions should not turn on identity/ownership, referencing Killegland Estates Ltd v. Meath County Council [2023] IESC 39 (Hogan J.: planning and zoning “blind” to ownership). Woulfe J. considered the High Court’s “alerting” rationale inconsistent with equal treatment of submissions on their merits.

(e) De minimis, substantial compliance, mandatory/directory, and discretion: from Alf-a-Bet to Gillen

The Court undertook a wide review of authorities on procedural non-compliance:

  • Monaghan Urban District Council v. Alf-a-Bet Promotions Ltd [1980] ILRM 64: Henchy J.’s formulation that even “obligatory” requirements may be overlooked only where deviation is so trivial/technical/peripheral that the obligation is substantially complied with—placing the burden on the party seeking excuse.
  • The State (Elm Developments Limited) v. An Bord Pleanála [1981] ILRM 108: the “mandatory vs directory” distinction depends on the statutory scheme and whether the requirement is integral and indispensable.
  • McAnenley v. An Bord Pleanála [2002] 2 IR 763 and Ní Chonghaile v. Galway County Council [2004] 4 IR 138: illustrate the courts’ varying responses where non-compliance exists—sometimes treating defects as not excusable, sometimes applying de minimis where no-one is misled.
  • Ballyedmond v. Commission for Energy Regulation [2006] IEHC 206: Clarke J.’s statement that significant unauthorised deviations from mandated procedure cannot be ignored.
  • Gillen v. Commissioner of An Garda Síochána [2012] 1 IR 574: the Court treated Gillen as the best modern synthesis—reframing “mandatory/directory” as ultimately a question whether the legislature intended invalidity. Woulfe J. expressly endorsed Finnegan J.’s two-stage structure and applied it as the organising principle for planning judicial review.

(f) Post-Gillen planning cases and “harmless error”

The Court acknowledged that some planning decisions did not explicitly cite Gillen, including: Byrnes v. Dublin City Council [2017] IEHC 19 (failure to include any list under s. 179(3)(b)(iii) treated as minor/trivial in discretion), and Southwood v. An Bord Pleanála [2019] IEHC 504 (breach undermining effective public participation; relief granted). Woulfe J. explained these through the lens of discretionary consequences rather than as displacing Gillen.

The judgment also situated the recent “harmless error” language—drawn from EU law and domestic application— as substantially overlapping with prejudice-based discretion: Case C-72/12 Altrip; Carrownagowan Concern Group v. An Bord Pleanála (No. 3) [2024] IEHC 549; Doyle v. An Bord Pleanála [2025] IEHC 158. The Court treated “harmless error” as, in effect, a modern label for the long-established inquiry into whether the defect made any material difference.

Finally, the Court referenced older Irish authority consistent with refusing relief absent prejudice, including The State (Toft) v. Galway Corporation [1981] ILRM 439 and Blessington and District Community v. Wicklow County Council [1997] 1 IR 273.

3.2 Legal Reasoning

  1. Text + agency: “made submissions” can truthfully describe the agent who lodged them and, by attribution, the principal who authorised them. The statute did not expressly confine “made” to principals only.
  2. Context of development plans: The Court placed significant weight on the development plan process as a large-scale, time-bound administrative exercise. Reading s. 12(8)(b)(i) to require investigation of agency relationships was considered inconsistent with a workable scheme.
  3. Purpose as administrative record-keeping: The list was treated as primarily ensuring formal recording/transparency of receipt and handling of submissions, especially in a system where (historically) submissions were not necessarily readily accessible to members.
  4. Consequences analysis (even though unnecessary): The Court clarified that, where the legislation does not prescribe invalidity, the court should not assume “automatic quashing”; instead it should ask whether invalidity is intended, and if not, whether discretion should be exercised given the nature of the breach, substantial compliance, prejudice/harmlessness, and public interest in stability of decisions.

3.3 Impact

  • Reduced vulnerability of development plans to clerical/naming defects: Planning authorities are less exposed to having development plans quashed solely because a CE list identifies a planning consultant rather than the underlying client, provided the submission is otherwise captured and processed.
  • Clarified compliance standard for s. 12(8)(b)(i): Authorities may list the agent, the principal, or both. Best practice may still favour “agent on behalf of principal” for clarity, but it is not a condition of validity on this judgment’s reading.
  • Doctrinal consolidation: The judgment is a significant Supreme Court statement importing and reaffirming the Gillen two-stage framework into planning judicial review: (i) interpret legislative intention on invalidity; (ii) if invalidity not intended, apply discretionary factors including de minimis, substantial compliance, prejudice, and the public interest.
  • Limits on identity-based “alerting” arguments: The Court’s rejection of the list as an “alerting” mechanism may constrain future challenges that attempt to build procedural prejudice from the proposition that members would have been more attentive if the submitter’s identity were highlighted.

4. Complex Concepts Simplified

Certiorari
A judicial review order quashing (setting aside) an administrative decision.
Mandatory vs directory
A traditional way of asking whether a statutory requirement must be strictly complied with on pain of invalidity. The Supreme Court emphasised that the real question is legislative intention: was invalidity meant to follow from breach?
De minimis / trivial breach
A very minor non-compliance that the court may overlook, particularly where the “spirit” of the requirement is met and no practical harm is shown.
Substantial compliance
Even if there is some departure from the literal requirement, the essential aim has been met sufficiently. The court treats the obligation as adequately performed in substance.
Harmless error
A defect that did not (and could not realistically) affect the outcome or impair participation/rights in any material way. The Court treated this as closely aligned with the prejudice inquiry long familiar in Irish judicial review.
Agent and principal
An agent (e.g. a planning consultant) acts with authority for a principal (the client). In law, authorised acts of the agent are attributable to the principal, so describing either as the “maker” of the submission can be correct depending on context and statutory wording.

5. Conclusion

[2026] IESC 36 establishes that the s. 12(8)(b)(i) requirement to “list the persons or bodies who made submissions” is satisfied by listing the submitter’s agent, the principal, or agent on behalf of principal. It also provides an important Supreme Court consolidation of how Irish courts should approach the consequences of procedural defects in planning law: interpret whether the legislature intended invalidity, and—if not—apply discretionary principles including de minimis/substantial compliance, prejudice (or harmlessness), and the public interest in orderly administration.