South Dublin County Council v Threshford Ltd and Ors, O'Neill v Branach Developments Ltd and Anor (Approved)

Factual and Procedural Background

The City planning authority (Company A) issued proceedings under s.160 of the Planning and Development Act 2000 seeking injunctive and restorative relief in respect of unauthorised works carried out from mid‑August 2025 at lands in The City (a former caravan/mobile‑home site). Company B, Company C and Company D were the entities responsible for the works; an individual (Applicant) living c.200 m from the lands also obtained s.160 relief in related proceedings. The Circuit Court (Judge O'Connor) heard both sets of s.160 applications on 4 and 9 December 2025 and on 19 December 2025 made orders restraining the unauthorised development and directing restoration. The entities appealed to the High Court (Judge Humphreys) and sought stays; a limited stay was granted by Judge Farrell permitting restricted weatherproofing works. The High Court heard the appeals on 13 May 2026, reserved judgment, circulated a draft on 22 May 2026, and delivered the judgment on 3 June 2026.

Legal Issues Presented

1. Whether the works constituted exempted development under s.4(1)(h) of the 2000 Act (maintenance, improvement or other alteration) or were new unauthorised development.
2. Whether certain affidavits and fresh evidence tendered on appeal should be admitted.
3. Whether the development pre‑dated 1 October 1964 (pre‑1964 defence) and the consequences of the seven‑year rule in s.160(6).
4. Whether tree cutting/vegetation works amounted to development and whether any exemption under s.4 applied.
5. The onus of proof applicable to an exemption defence and the consequences of absence of cross‑examination.
6. The exercise of the court's discretion under s.160 in light of objective and subjective factors.
7. The appropriate form of any mandatory/remedial order and costs consequences.

Arguments of the Parties

Company A's Arguments

• The photographic and affidavit evidence demonstrated demolition of caravan/mobile‑home type structures and construction of new dwelling‑type modular homes and extensive site works; the works were not maintenance or improvement under s.4(1)(h).
• The appellants failed to discharge the onus to show an exemption; their affidavit evidence was contradicted and in parts not reality‑based.
• Fresh affidavits filed on appeal were inadmissible under Order 61 r.8 RSC and s.37 Courts of Justice Act 1936 because no special leave was sought; in any event the content added nothing of substance.
• Tree‑cutting and site clearance are works constituting development and, given the context, not exempt; environmental assessment and appropriate assessment issues were not excluded.
• Objective factors (high amenity zoning, heritage/water/traffic impacts, continuation and intensification of works after warnings and proceedings) warranted full remediation and costs in favour of Company A.

Appellants / Respondents' Arguments (Companies B, C & D)

• The works were maintenance, improvement or alteration of existing structures and thus exempt under s.4(1)(h); foundations were retained and footprints/dimensions not increased.
• There was an established residential use said to date from before October 1964 (or longstanding use) and a seven‑year defence was invoked.
• Additional affidavit evidence (including from a planner and a deponent described as an architect) should be admitted and considered; the appellants sought to address aspects of form of order and alleged errors in the draft judgment.
• The appellants relied on authorities (including Michael Cronin (Readymix) and Cairnduff v O'Connell) to argue a broader margin for works covered by s.4(1)(h) and invoked defences such as genuine mistake and disproportionate hardship.

Table of Precedents Cited

Precedent	Rule or Principle Cited For	Application by the Court
Dublin County Council v. Hill [1994] 1 I.R. 86, [1992] I.L.R.M. 397	Historical enforcement attempt mentioned in factual history.	Referenced as part of prior enforcement history on the lands.
O'Sullivan v. Health Service Executive [2023] IESC 11 (Unreported, Supreme Court, 10 May 2023)	Draft judgment procedure and limits on reargument.	Invoked to explain limits of draft‑judgment comments (para.72).
O'Sullivan v. Sea Fisheries Protection Authority [2017] IESC 75, [2017] 3 I.R. 751, [2018] 1 I.L.R.M. 245	Limits on procedures that approximate criminal trial in draft judgment engagement.	Cited to caution against treating draft process as new substantive hearing.
Attorney General v. Crosland (No. 2) [2021] UKSC 58, [2022] 1 W.L.R. 367	Why restriction on publication of draft judgments is in the interests of administration of justice.	Supported Court's direction on confidentiality of the draft judgment.
Baigent v. Random House Group Ltd [2006] EWHC 1131 (Ch), [2006] 5 WLUK 45	Confidentiality and handling of draft judgments.	Referred to in context of draft judgment confidentiality guidance.
R. (Counsel General for Wales) v. Secretary of State for Business, Energy and Industrial Strategy [2022] EWCA Civ 181, [2022] 1 W.L.R. 1915	Procedural authority on handling draft judgments.	Used for guidance on draft judgement practice.
Public Institution for Social Security v. Banque Pictet & Cie SA and others [2022] EWCA Civ 368	Confidentiality of draft judgments.	Referred to in support of draft judgment confidentiality direction.
Itkin v. Wood [2023] JRC 101 (Unreported, Royal Court of Jersey, 22 June 2023)	Draft judgment confidentiality examples.	Cited with other authorities to justify confidentiality direction.
Tesco Ireland Limited v. Stateline Transport Limited [2024] IECA 46	Rule that court is not obliged to accept vague and unsubstantiated averments.	Applied to reject vague/unsubstantiated averments by respondents.
South Dublin County Council v. Fallowvale Limited [2005] IEHC 408 (Unreported, High Court, McKechnie J., 28 April 2005)	Onus on defendant to establish exempted development.	Used to state the onus lies with the respondents to prove exemption.
Doorly v. Corrigan [2022] IECA 6 (Unreported, Court of Appeal, 21 January 2022)	Onus of proof and matters the court may have regard to when evaluating evidence.	Cited in support of resolving conflicts of evidence against party bearing onus.
Diamrem Ltd. v. Cliffs of Moher Centre Ltd [2018] IEHC 654 and [2021] IECA 291	Affidavit evidence must enable defence to be distilled from the evidence; fresh evidence rules.	Applied to refuse admission/weight to fresh evidence not before Circuit Court.
Michael Cronin (Readymix) v. An Bord Pleanála [2017] IESC 36, [2017] 2 I.R. 658	Discussion of margin in exemption context (noted by respondents).	Court held the case has no bearing to civil enforcement standard asserted by respondents.
RAS Medical Ltd v. Royal College of Surgeons in Ireland [2019] IESC 4, [2019] 1 I.R. 63	Where conflict of admissible evidence exists, absence of cross‑examination generally leads to resolution against the party bearing the onus.	Applied: respondents failed to cross‑examine; conflicts resolved against them.
Re Bayview Hotel (Waterville) Limited [2022] IEHC 516	Court may prefer affidavit over oral evidence where appropriate; evaluation of inherent defects in evidence.	Cited to support court's ability to assess inherent credibility issues in affidavits.
Koulibaly v. Minister for Justice, Equality and Law Reform [2004] IESC 50, [2004] 7 JIC 2906	Affidavit credibility and court's role in preferring evidence.	Used by analogy to justify evaluating and preferring one account over another.
Murphy v. Minister for Defence [1991] 2 I.R. 161	Strict rules on admission of fresh evidence on appeal; need for special leave.	Applied to refuse admission of affidavits not put before Circuit Court without special leave.
Emerald Meats v. Minister for Agriculture [2012] IESC 48	Rules on admission of fresh evidence on appeal are strict; finality of litigation.	Referred to support refusal to admit late affidavits and fresh evidence.
Student Transport Scheme Limited v. Minister for Education and Skills [2015] IECA 303	Strict approach to fresh evidence; need for special leave where evidence was available earlier.	Applied to conclude late affidavits should not be admitted.
Wicklow County Council v. Beattie [2018] IEHC 282	Order 61 r.8 and s.37 engagement in s.160 appeals referenced.	Cited as example of refusing late evidence without special leave.
Kerry County Council v. McElligott [2021] IEHC 542	Fresh evidence rules and need for special leave; s.160 appeals practice.	Applied as authority that respondents should have sought special leave.
Lyons v. McDonagh [2024] IEHC 471	Requirement to apply for special leave to tender fresh evidence on appeal.	Referred to support inadmissibility of affidavits filed on appeal.
Dillon v. Irish Cement Limited 2004 WJSC-SC 2866, [1986] 11 JIC 2602	Exemptions to be construed strictly.	Used to justify narrow construction of s.4(1)(h).
Corajio Unlimited v. An Bord Pleanála [2023] IEHC 373	Strict construction of exempted development categories.	Applied to reinforce narrow approach to s.4 exemptions.
Leitrim County Council v. Dromaprop Ltd [2024] IEHC 233	Exemptions construed narrowly; relevant to s.4(1)(h).	Relied on for strict approach to exemption.
Cairnduff v. O'Connell 1986 WJSC-SC 209, [1986] I.R. 73, [1986] I.L.R.M. 465	Principle that total or near‑total replacement is not maintenance/improvement/alteration.	Main authority for holding that substantial replacement cannot be an exemption.
Dublin Corporation v. Arnold Lowe and Signway Holdings Limited [2000] IEHC 161	Replacement vs improvement distinction.	Cited in support of principle that substantial replacement is not exempted.
Fingal County Council v. Crean [2001] IEHC 148	Authority on exempted development interpretation.	Used to show consistent caselaw on scope of s.4 exemptions.
Dublin City Council v. Lowe [2004] IESC 106, [2004] 4 I.R. 259	Replacement/maintenance distinction reinforced at appellate level.	Referred to support narrow construction of s.4(1)(h).
McCabe v. Coras Iompair Éireann and Iarnród Éireann [2006] IEHC 356, [2007] 2 IR 392	Relevant caselaw on replacement vs repair principles.	Listed among authorities showing total replacement is not an exemption.
Sligo County Council v. Martin [2007] IEHC 178	Consequences of granting relief or withholding relief; integrity of planning system and public participation.	Applied to support remedial relief where enforcement is necessary to protect public interest.
Pierson v. Keegan Quarries Ltd [2010] IEHC 404	Intensification and requirement for permission.	Used to show intensification defeats seven‑year defence.
Wicklow County Council v. Lee [2019] IEHC 19	Abandonment/resumption and seven‑year defence principles.	Applied to show abandonment/resumption defeats seven‑year defence.
Lanigan and Benghazi Ltd t/a Tullamaine Castle Stud v. Barry and Motor Speedway Ltd t/a Tipperary Raceway [2008] IEHC 29	Intensification requires permission; significance for seven‑year rule.	Referred to among authorities on intensification defeating long‑use defences.
Cork County Council & Ors v. Slattery Pre Cast Concrete Ltd & Ors [2008] IEHC 29	Case law on development/use changes requiring permission.	Listed in discussion of intensification and need for permission.
Lanigan v. Barry [2016] IESC 46, [2016] 1 I.R. 656	Supreme Court authority on intensification and permission necessity.	Referenced to show intensification may require planning permission.
Kildare County Council v. Goode [1999] IESC 43, [1999] 2 I.R. 495	Abandonment/resumption principles and long‑use defences.	Cited as authority on abandonment defeating long‑use defences.
Patterson v. Murphy [1978] I.L.R.M. 85	Intensification/works requiring permission.	Listed in authorities on intensification and permission.
Killegland Estates Ltd v. Meath County Council [2023] IESC 39, [2023] 12 JIC 2109	Planning decisions and separation of powers; objective approach to planning decisions.	Applied to caution against subjective considerations in enforcement discretion.
daa v. Fingal County Council [2024] IEHC 589	Application of Killegland principles to planning disputes.	Used to support objective weighting in discretion analysis.
Krikke v. Barranafaddock Sustainability Electricity [2020] IESC 42	Public importance of orderly operation of planning code and approach to remedies.	Quoted for the proposition that relief will only be refused in exceptional circumstances.
Meath County Council v. Murray [2018] 1 IR 189	Factors the court can consider in exercising discretion under s.160.	Relied on for factors relevant to discretionary relief.
Lawlor v. Dundalk Town Council [2005] IEHC 73, [2005] 2 I.L.R.M. 106	Form and clarity of enforcement relief.	Considered and distinguished on facts re: self‑executing enforcement notices versus equitable injunctions.
Rehabilitation Institute v. Dublin Corporation 1988 WJSC-HC 626, [1988] 1 JIC 1401	Ancillary works doctrine (when ancillary works may be treated with main use).	Court noted that ancillary works argument cannot succeed where substantive development is not exempt.
Rutledge v. Fingal County Council [2026] IEHC 223	Abandonment/resumption principles in relation to uses.	Applied analogously to works to show abandonment defeats seven‑year defence.
Clonres v. An Bord Pleanála [2021] IEHC 303	Permission for inconsistent use can be evidence of abandonment.	Referred to among authorities on abandonment/resumption.
Murphy v. An Bord Pleanála [2024] IEHC 186	Case on abandonment/resumption and planning permission consequences.	Referenced in context of abandonment/resumption principles.
Ó Murthuile v. An Bord Pleanála [2026] IEHC 36	Recent authority on use/abandonment principles.	Cited to illustrate contemporary jurisprudence on abandonment/resumption.

Court's Reasoning and Analysis

The court proceeded by considering the admissibility of fresh evidence, the factual findings, statutory definitions and applicable caselaw, and the exercise of discretion under s.160.

Admissibility: The appellants sought to introduce affidavits on appeal (de bene esse filings). The court applied Order 61 r.8 RSC and s.37 Courts of Justice Act 1936, concluding no special leave had been sought and that the new evidence was therefore inadmissible or entitled to little weight. The court emphasised the strict rules on fresh evidence and finality of litigation (Murphy; Emerald Meats; Student Transport; Wicklow v. Beattie; Kerry v. McElligott).

Onus and evidence: The court reiterated that the respondents/appellants bore the onus of proving the works were exempted development (South Dublin County Council v. Fallowvale; Doorly v. Corrigan). Where admissible evidence conflicted and there was no cross‑examination, conflicts were resolved against the party bearing the onus (RAS Medical). The court found significant credibility problems in respondent affidavits, including misdescription of a deponent as an "architect" when not registered and statements that "fly in the face of reality."

Definition of development and tree works: The court examined s.3 and s.2 of the 2000 Act and concluded that cutting trees/hedges and other works are "works" on land and thus development, subject to exemptions; s.4 expressly contemplates tree works as exempt in limited circumstances.

Exemption under s.4(1)(h): The court applied established authority that exempted categories are construed narrowly (Dillon; Corajio; Leitrim v. Dromaprop). The court held two insuperable obstacles to the respondents' s.4(1)(h) defence: (i) total or near‑total replacement is not maintenance/improvement/alteration (Cairnduff; Dublin City Council v. Lowe; cretoria cited); and (ii) the works materially affected external appearance so as to render the new structures inconsistent with prior character. Photographic evidence showed demolition and complete replacement with larger, different dwellings and new foundations; some parts of the site had no prior structures and could not therefore be "improvements". The court rejected the appellants' foundation/footprint arguments and held such contentions insufficient given the onus and contrary photographic evidence.

Seven‑year / pre‑1964 defence: The court found no evidential basis for a pre‑1964 defence; even if historic use had existed, the intensive works commencing August 2025 constituted a new development and any seven‑year defence was defeated by abandonment/intensification principles (Rutledge; Patterson; Wicklow v. Lee and authorities cited).

Discretion under s.160: The court set out objective and subjective considerations. Objective factors (integrity of planning system; high‑amenity zoning; traffic, water, heritage impacts; continued works despite warnings and proceedings) overwhelmingly favoured granting full remedial relief. Subjective factors (any hardship claimed) carried limited weight and were not established here. The court emphasised the separation of powers and that denying enforcement would amount to de facto permission contrary to statutory scheme (Killegland; Meath v. Murray; Krikke).

Form of relief and costs: The court found s.160 empowered wide remedial orders, including removal, restoration and consequential measures, and that the precise form should be the subject of limited submissions within the contours of the judgment. The court accepted that, in practice, the planning authority may be required to carry out remediation if respondents fail to comply. Costs were to follow the event subject to s.161(1) and (2).

Holding and Implications

APPEALS DISMISSED; CIRCUIT COURT ORDERS AFFIRMED

Holding: The High Court dismissed the appeals, affirmed the Circuit Court s.160 orders (varied to include prohibitory, mandatory and ancillary relief as described), and ordered that respondents submit a detailed remediation and landscaping plan and comply with timelines for removal of unauthorised works and restoration. Costs were ordered against the respondents in both the Circuit Court and High Court (with taxation/adjudication mechanisms specified).

Implications: The direct effect is that the respondents must remove structures erected since August 2025, restore the lands in accordance with a remediation plan (or surrender vacant possession for council remediation), and pay costs. The decision applies established principles rather than creating new precedent: exemptions are to be construed narrowly; total or near‑total replacement is not maintenance/improvement; fresh evidence on rehearing requires special leave; the court's discretion under s.160 predominantly favours enforcement where objective factors demand it. No new legal principle was established beyond application of settled authorities.