Section 12(8)(b)(i) PDA 2000: Listing a Submission “Maker” Includes the Agent, the Principal, or “Agent on Behalf of”—and Minor Procedural Errors Do Not Necessarily Ground Certiorari

1. Introduction

This Supreme Court decision (O'Donnell v Dublin City Council (Approved) [2026] IESC 36) concerns the validity of a Dublin City Council development plan decision where, in the Chief Executive’s (“CE”) statutory report on submissions relating to a proposed material alteration, the CE listed the respondent’s planning agent (“Doyle Kent Ltd”) rather than the respondent company as the submitting party.

The dispute arose in the context of the adoption of the Dublin City Development Plan 2022–2028, specifically a material alteration (MA D-0004) rezoning lands owned by the notice party (the “Uniphar site”) from employment/enterprise zoning to mixed-use zoning. The respondent company owns adjoining industrial lands and argued that residential-led redevelopment would be incompatible with its operations.

The High Court (Holland J.) quashed the development plan decision by certiorari, holding that s. 12(8)(b)(i) of the Planning and Development Act 2000 (the “2000 Act”) imposed a mandatory obligation to list the principal who made the submission, not merely the agent. Dublin City Council appealed.

Key issues

1. Construction of s. 12(8)(b)(i): What is the purpose/intention of the requirement to “list the persons or bodies who made submissions”, and is it satisfied by listing an agent?
2. De minimis / substantial compliance: If there were a breach of a mandatory statutory obligation, can it be treated as de minimis?
3. Remedy / certiorari: What principles govern whether a breach of planning statutory requirements should lead to quashing?

2. Summary of the Judgment

Woulfe J. (delivering judgment on 2 July 2026) allowed the appeal and set aside the High Court order of certiorari.

• No breach: Properly construed, s. 12(8)(b)(i) is complied with if the CE lists (a) the agent, (b) the principal, or (c) “agent on behalf of principal”. Listing “Doyle Kent Ltd” therefore satisfied the statutory requirement.
• Even if there were a breach: The Court endorsed the analytical approach in Gillen v. Commissioner of An Garda Síochána [2012] 1 IR 574 (a two-stage inquiry) and stated that, on the assumed facts, any non-compliance would be trivial/technical, caused no demonstrated prejudice, and would not justify certiorari (a “harmless error”).

3. Analysis

3.1 The statutory setting: development plans, material alterations, and the CE report

Under the development plan process, the elected members adopt the plan, but they do so informed by a CE report which (under s. 12(8)(b)) must:

1. list the persons/bodies who made submissions/observations;
2. summarise those submissions/observations; and
3. give the CE’s response to the issues raised.

The High Court treated the “list” requirement as serving a democratic/representational function: helping elected members identify which submissions to focus on by knowing who made them (particularly local constituents and employers). The Supreme Court rejected that as the controlling interpretation.

3.2 Precedents cited and their influence

(A) Statutory interpretation method: Heather Hill v. An Bord Pleanála [2022] IESC 43

The Supreme Court treated Heather Hill as the “method statement” for interpretation: start with ordinary meaning, read in context (including statutory scheme, practical operation), and only then consider purpose if ambiguity remains. The Court considered that applying the Heather Hill approach yielded a clear meaning: “persons who made submissions” can naturally include either the agent (who physically lodges it) or the principal (on whose behalf it is made), or both.

(B) Agency and “who acted”: Donegal County Council v. Quinn [2025] IESC 19 and Dalton v. An Bord Pleanála [2020] IEHC 27

A central move in the reasoning was to treat “who made” as capable of embracing both operational and juridical actors, particularly where agency is involved. The Court drew a close analogy with Donegal County Council v. Quinn [2025] IESC 19, where a statutory requirement to specify the “person who applied” for a summons was held satisfied by naming either the prosecutor (principal) or solicitors (agent), or both. The Court used this to support the proposition that identifying the agent is not “wrong” or “non-compliant” where the agent is indeed the entity that made the submission in a literal and authorised sense.

The High Court had relied on orthodox agency principle (as referenced in Dalton v. An Bord Pleanála [2020] IEHC 27) to argue that the principal is the “real” submitter. The Supreme Court effectively accepted agency doctrine but drew a different conclusion: agency doctrine means the act can properly be attributed to the principal, but it does not mean the agent is an invalid descriptor of “who made” the submission.

(C) Ownership and planning “blindness”: Killegland Estates Ltd v. Meath County Council [2023] IESC 39

The High Court distinguished Hogan J.’s statement in Killegland that planning/zoning should generally be blind to ownership, reasoning that the Oireachtas created a specific statutory exception by requiring names to be listed. The Supreme Court instead treated the High Court’s “alerting elected members” theory as inconsistent with the “blindness” principle: submissions should be evaluated on content, not on the identity of the submitting party. On that view, the list is more plausibly administrative (recording/verification) than a mechanism to privilege certain submissions for attention.

(D) Workability and administrative burden: Save Cork City Community Association CLG v. An Bord Pleanála [2024] 1 IR 205 and Waltham Abbey v. An Bord Pleanála [2022] 2 ILRM 417

The Court invoked a “workable interpretation” approach, citing its own earlier reliance on Hogan J.’s statement in Waltham Abbey (as discussed in Save Cork City Community Association CLG) that statutes should, where possible, be construed to produce a coherent and workable scheme. The development plan process involves large volumes of submissions and tight timelines (here, 1,096 submissions on material alterations, with an eight-week statutory deadline). Requiring the CE to “look behind” each named submitter to determine whether it is an agent and then identify the principal was considered an additional burden risking delay and undermining workable administration.

(E) Mandatory/directory, de minimis, substantial compliance, and remedy discretion: from Alf-a-Bet to Gillen

Although the Court held there was no breach, it went on (because of public importance) to articulate the governing framework for the consequences of breach.

• Monaghan Urban District Council v. Alf-a-Bet Promotions Ltd [1980] ILRM 64: Henchy J.’s formulation anchors the “substantial compliance / de minimis” idea: even where a procedure is prescribed as obligatory, deviation may only be overlooked if trivial/technical/peripheral/insubstantial such that the obligation is substantially complied with.
• The State (Elm Developments Limited) v. An Bord Pleanála [1981] ILRM 108: introduced a strong “integral and indispensable” test for whether apparent “shall” requirements are truly mandatory, but also permitted overlooking technical breaches in the interests of justice where the requirement is essentially informative/directory.
• McAnenley v. An Bord Pleanála [2002] 2 IR 763 and Ní Chonghaile v. Galway County Council [2004] 4 IR 138: illustrate the tension: difficulty of treating express statutory non-compliance as de minimis, yet the court may still refuse certiorari where the error misled no one and caused no injustice.
• Ballyedmond v. Commission for Energy Regulation [2006] IEHC 206: emphasised that “significant and unauthorised” deviation from mandated procedure cannot be ignored—language the Supreme Court treated as consistent with the substantial compliance/de minimis spectrum.
• Gillen v. Commissioner of An Garda Síochána [2012] 1 IR 574: the Court treated Gillen as providing the modern organising framework. It endorsed Finnegan J.’s two-part approach (itself influenced by R v. Soneji [2006] 1 AC 340 and Project Blue Sky Inc. v. Australian Broadcasting Authority (1998) 194 CLR 355):
  1. Did the legislature intend invalidity to result from breach?
  2. If not, has there been substantial compliance / is the breach de minimis, considering prejudice, injustice, and public interest?

(F) Planning cases and discretion not to quash: Byrnes, Southwood, and “harmless error”

The Court noted that some planning cases have not explicitly applied the Gillen structure:

• Byrnes v. Dublin City Council [2017] IEHC 19: despite an entire omission of the statutory “list” of submitters in a s. 179 context, the High Court refused to quash, describing the error as minor/trivial and emphasising the discretionary nature of judicial review (with reference to McMahon v. An Bord Pleanála [2010] IEHC 431). The Supreme Court suggested this outcome can be understood as, in substance, an exercise akin to stage-two discretion.
• Southwood v. An Bord Pleanála [2019] IEHC 504: illustrates the opposite situation: non-compliance affecting effective public participation (a missing online document relating to protected species) was not trivial and led to quashing.

The Court also addressed the “harmless error” strand, linked to EU law language from Case C-72/12 Altrip and recent High Court decisions (including Carrownagowan Concern Group v. An Bord Pleanála (No. 3) [2024] IEHC 549 and Doyle v. An Bord Pleanála [2025] IEHC 158). Woulfe J. treated “harmless error” as largely a modern label for a familiar discretionary factor: absence of prejudice to the applicant/public (with earlier Irish examples including The State (Toft) v. Galway Corporation [1981] ILRM 439 and Blessington and District Community v. Wicklow County Council [1997] 1 IR 273).

3.3 The Supreme Court’s legal reasoning

(1) Ordinary meaning: “persons … who made submissions” can include agent or principal

The Court held that listing “Doyle Kent Ltd” satisfied s. 12(8)(b)(i) because:

• the agent literally made/lodged the submission;
• by agency principles, the principal also “made” the submission; and
• there is no textual requirement that the CE must identify the underlying principal as distinct from the entity that actually transmitted the submission.

The Court therefore rejected the High Court’s binary approach (“only the principal counts”), and instead adopted a permissive compliance set: agent, principal, or “agent on behalf of”.

(2) Context and workability: development plan scale and statutory time constraints

The Court treated the planning context as decisive. The CE must compile a list, summary, and responses within eight weeks. Imposing an implied duty to investigate whether a named submitter is an agent and to identify its principal would add administrative burden and risk delay. The Court viewed its interpretation as better aligned with a workable statutory scheme.

(3) Purpose: administrative recording rather than “alerting elected members”

While the Court considered purpose not strictly necessary given the clarity it found, it nonetheless preferred the Council’s “administrative recording/verification” explanation over the High Court’s “alerting” function, for several reasons:

• it fits the text and the overall structure of s. 12(8)(b) as an administrative reporting device;
• it is consistent with the general planning principle (as expressed in Killegland) that identity/ownership is ordinarily irrelevant to the merits;
• historically, when s. 12(8) was enacted there was no obligation to publish submissions online (only later introduced by the Planning and Development (Amendment) Act 2018 inserting s. 12(8A)), weakening the idea that the list was meant to help members select submissions to read; and
• there was no evidence from elected members supporting the asserted “alerting” function.

(4) Remedy framework (obiter but authoritative): endorsing Gillen for planning statutory breaches

Even though unnecessary to dispose of the appeal, the Court set out a structured approach for when statutory non-compliance is alleged under the 2000 Act:

1. Stage 1 (interpretation): ask whether the legislature intended invalidity to result from the breach (using Heather Hill-style interpretation: text, context, scheme, purpose).
2. Stage 2 (discretion): if invalidity is not intended, the court exercises discretion considering all relevant circumstances, including substantial compliance, whether the breach is trivial/technical/de minimis, prejudice (or lack of it) to the applicant/public, and countervailing public interest.

Applying that framework hypothetically, the Court indicated it would not infer legislative intent to invalidate a development plan because of how a submitter is named on the list; and, absent prejudice, any such misnaming would be a trivial “harmless error” not warranting certiorari.

3.4 Impact of the decision

(A) Practical operation of development plan processes

The decision reduces the risk that development plans (and potentially other planning processes with “list submitters” obligations) will be vulnerable to judicial review on the narrow basis that a CE listed a planning consultant/agent rather than the underlying client/principal. In high-volume exercises with short statutory timelines, the ruling supports administrative practicality.

(B) Clarification of “listing” compliance standards

A clear compliance rule emerges: for s. 12(8)(b)(i), naming the agent is not inherently an error. Planning authorities may still prefer “agent on behalf of principal” as best practice for transparency, but the Court has held it is not legally required as a condition of validity.

(C) Doctrinal consolidation: Gillen as the organising framework for consequences of procedural breaches

The Court’s endorsement of Gillen (and its emphasis on legislative intent for invalidity, followed by discretionary analysis) is likely to influence how Irish courts structure their reasoning in planning judicial reviews involving procedural defects—potentially making outcomes more predictable and explicitly tied to statutory construction plus demonstrated prejudice/public interest.

(D) “Harmless error” placed within Irish discretionary tradition

By treating “harmless error” as essentially the absence-of-prejudice limb of the discretion analysis, the Court signalled that (outside express invalidity provisions) Irish planning judicial review will generally not favour quashing for purely formal errors that do not affect participation, consideration, or outcome.

4. Complex Concepts Simplified

4.1 Certiorari

Certiorari is a court order that quashes (sets aside) an administrative decision. In planning, it can invalidate permissions, plans, or steps in statutory processes. It is discretionary, not automatic.

4.2 Mandatory vs directory requirements

Courts historically asked whether a statutory “shall” requirement is “mandatory” (breach invalidates) or “directory” (breach may be excused). This case (following Gillen) treats that classification as secondary to the real question: did the legislature intend invalidity as the consequence?

4.3 De minimis and substantial compliance

De minimis means too trivial to matter legally. Substantial compliance means the essential substance of the obligation was fulfilled even if not perfectly executed. Under Alf-a-Bet, even an “obligatory” requirement may sometimes survive minor defects if the breach is trivial/technical/peripheral and the obligation is substantially met.

4.4 Harmless error

A harmless error is a defect that causes no material prejudice and makes no difference to the legality or outcome in any meaningful way. The Court treated this as overlapping with the traditional Irish discretion/prejudice analysis.

4.5 Agency in submissions

Where a planning consultant submits on behalf of a client, both can sensibly be described as having “made” the submission: the consultant operationally lodges it; the client authorises it and is legally responsible for it. This case holds that the statute accommodates either description for listing purposes.

5. Conclusion

The Supreme Court held that s. 12(8)(b)(i) of the 2000 Act is satisfied where the CE lists the submitting agent, the principal, or “agent on behalf of principal”. On that basis, there was no statutory breach and the High Court’s quashing order was set aside.

More broadly, the judgment consolidates a structured approach—drawn from Gillen and consistent with Heather Hill—for assessing the consequences of procedural non-compliance in planning law: first determine whether invalidity was intended by the legislature; if not, exercise judicial review discretion with close attention to substantial compliance, triviality, prejudice, and public interest. The decision therefore strengthens legal certainty and administrative workability in development plan-making, while preserving the courts’ capacity to quash decisions where procedural defects are significant, participation-affecting, or prejudicial.