Derelict Sites CPOs: “Occupier” Includes Unlawful Occupants, but Defective Service May Be Cured by Actual Notice, Participation, and Delay

1. Introduction

This decision concerns a local authority’s attempt to recover possession of a derelict dwelling at 18 Cadogan Road, Fairview, Dublin 3, acquired by compulsory purchase under the Derelict Sites Act 1990. The local authority sought orders requiring the defendants—individuals occupying the property, and “persons unknown”—to vacate so that urgent works could be carried out and the dwelling returned to use as social housing.

The central dispute did not turn on whether the building was derelict (the statutory process had already determined that), but on whether the compulsory purchase order (“CPO”) and vesting order were invalid due to defective statutory notice to an occupant, and—if title was valid—whether eviction would be disproportionate given constitutional and Convention “home” protections.

Although several individuals were named, only two defendants actively participated at the special hearing; the judgment’s core legal findings arise from the arguments advanced by the remaining “live” occupant-defendant (unrepresented).

2. Summary of the Judgment

• “Occupier” under the Act includes unlawful occupiers: the Court held that a person in factual control of the land can fall within the inclusive statutory definition of “occupier”, even if occupying without lawful entitlement.
• Defective service was established: the local authority failed to comply with s.6(1) because the CPO notice was not addressed to the relevant occupant by name; and it could not rely on s.6(2) (“name cannot be ascertained by reasonable inquiry”) because it had not shown reasonable inquiry.
• Nonetheless, the CPO/vesting order stood: because the occupant had actual notice, objected and participated in the CPO process without raising service defects, suffered no prejudice, and delayed—she was barred (waiver/estoppel/approbate-and-reprobate, and delay) from using service defects to mount a late collateral challenge to title in the possession proceedings.
• Eviction was proportionate: applying the constitutional and ECHR proportionality framework (drawing especially on Clare County Council v McDonagh [2022] IR 122), the Court held that, despite personal vulnerabilities, eviction was necessary and proportionate to vindicate lawful title, abate dereliction risks, and enable social housing allocation through the lawful scheme rather than self-help occupation.

3. Analysis

3.1 Statutory architecture and the service dispute

The local authority’s title depended on a valid CPO route under the Derelict Sites Act 1990, in particular:

• s.15(1)(b): the authority must serve notice of intention to acquire on “every owner, lessee and occupier” (subject to the tenant exception).
• s.6(1): notices must be “addressed to the person concerned” and served by specified methods (including leaving at the residence).
• s.6(2): if the occupier’s name “cannot be ascertained by reasonable inquiry”, the notice may be addressed to “the occupier”.
• s.17–s.18: following An Bord Pleanála consent, a vesting order vests the fee simple free from encumbrances on the vesting date.

The Court accepted that affixing the notice to the property’s railings/gate was, as a matter of location/visibility, adequate. The defect lay elsewhere: the authority addressed it generally to “the occupants” rather than to the particular occupant by name, and it did not establish a factual basis for invoking s.6(2) because it had not taken meaningful steps (such as attending to ask identities) to ascertain names by “reasonable inquiry”.

3.2 The meaning of “occupier”: unlawful occupation can still qualify

A key interpretive holding is the Court’s refusal to read “lawful” into “occupier”. The authority argued that extending service/objection rights to trespassers would be “absurd” and would confer greater procedural rights than those given to very short-term tenants.

Kennedy J rejected that implied restriction. The inclusive definition—“includes any person … having, for the time being, control of the land”—naturally captured a person exercising factual control, even if that control was not legally authorised. The Court was influenced by orthodox statutory interpretation: if the Oireachtas had intended to confine “occupier” to lawful occupiers it could have said so, and the Court cautioned against policy-driven re-writing, citing Heather Hill v An Bord Pleanála [2022] IESC 13.

Practical consequence: where a property is in fact occupied (including by “squatters”), a local authority should assume s.15(1)(b) is engaged and should either identify and name occupants (where reasonably possible) or build an evidential record of “reasonable inquiry” to rely on s.6(2).

3.3 Why the defective service did not unravel the CPO

Despite finding non-compliance with s.6(1) and inability to rely on s.6(2), the Court held that the vesting order remained effective and could be enforced. The reasoning is best understood as a convergence of procedural fairness, waiver/estoppel, and public-law timing discipline.

• Actual notice and no prejudice: the occupant demonstrably received the notice, understood it, and objected within time; the statutory purpose of notification (participation and opportunity to be heard) was achieved in substance.
• Waiver / approbate and reprobate: having participated in the statutory process to its conclusion without raising defective service, the occupant could not later treat the process as valid for participation but invalid for enforcement once unsuccessful.
• Delay as a bar: the challenge was articulated only months after the vesting order (and in defence to possession proceedings), when any defect could have been cured earlier by re-service with limited delay.
• Collateral challenge disfavoured: the Court aligned with the idea that challenges to vesting orders ordinarily belong in timely judicial review, relying by analogy on the delay reasoning in Tobin v Limerick City and County Council & Ors [2023] IEHC 626 and the collateral-attack concern reflected in Doran v Tailte Éireann [2023] IEHC 209.

The Court also observed that even if judicial review had been brought, discretionary relief would likely have been refused because the defect caused no prejudice, the challenge was delayed, and quashing would likely be nugatory (the CPO would predictably be recommenced and re-confirmed) while harming public interest objectives.

3.4 Precedents cited and how they shaped the outcome

(a) Dereliction definition and statutory purpose

The Court referenced Hussey & Ors v Dublin City Council [2007] IEHC 425 as a helpful analysis of the statutory definition of “derelict site”. While dereliction was not ultimately re-litigated in the enforcement proceedings, this contextualised the public interest underpinning the Act: preventing continued dereliction and enabling active land management, including CPOs, to remediate derelict structures.

(b) Possessory title authorities (raised by defendants)

The defendants invoked classical possession principles—Kennan v Murphy (1880) 8 LR IR 285, Webb v Ireland [1988] I.R. 353, [1988] I.L.R.M. 565, and the possession test in JA Pye (Oxford) Ltd v Graham [2003] 1 A.C. 419—to argue that physical control gives a superior right to possession against anyone who cannot show better title.

The Court treated these points as largely beside the statutory mechanism: the Derelict Sites Act can lawfully transfer title via vesting order provided statutory steps are complied with, and once the vesting order stands, possessory claims cannot defeat it. The real work these cases did in the judgment was narrower: they helped illustrate why “occupation” is a factual condition (control) rather than necessarily a lawful entitlement—supporting the Court’s broad reading of “occupier” (even though the Court did not have to validate any possessory title claim).

The defendants also cited Hume v Tennyson [1987] NI 139, [1987] 2 NIJB 12 for the proposition that prior possession can ground an action in trespass. Again, the Court accepted the general proposition but held that the vesting order resolved the “better title” question in the authority’s favour.

(c) Service where identity is unknown

On “reasonable inquiry” before serving generically, the Court considered Pepper Finance Corporation (Ireland) v. Persons Unknown [2023] IESC 21 relevant by analogy. Although it concerned service of court orders (and contempt), it reinforced a broader procedural principle: where parties are unknown, a claimant must demonstrate appropriate, reasonable efforts and a method likely to bring proceedings (or notices) to attention. In this case, the absence of meaningful inquiry prevented reliance on s.6(2).

(d) Public law timing and finality: Tobin and Doran

Tobin v Limerick City and County Council & Ors [2023] IEHC 626 was relied on primarily for delay and the disciplined approach to time limits in challenges to vesting orders. Kennedy J distinguished aspects of Tobin on “occupier” (it did not conclusively decide whether a bare licence suffices) but drew on its delay/finality logic.

Doran v Tailte Éireann [2023] IEHC 209 supported the Court’s reluctance to allow a collateral challenge to a completed statutory outcome when the proper route was a timely direct challenge.

(e) Article 8 ECHR and Article 40.5: eviction proportionality

The Court rejected the authority’s submission that unlawful occupiers cannot rely on “home” protections. It drew on:

• The People (Director of Public Prosecutions) v. Lynch [2009] IECCA 31, [2010] 1 IR 543 for the proposition that whether a place is a “dwelling” is a factual question.
• European authorities cited by the defendants—Chiragov and Others v. Armenia, no. 13216/05, ECHR 2011, McCann v. The United Kingdom [2008] 47 EHRR 40, and Winterstein v. France [2013] ECHR 984—as supporting that Article 8 “home” can be engaged even absent domestic-law entitlement.
• The Supreme Court framework in Clare County Council v McDonagh [2022] IR 122, and the diluted-but-real protection for unlawful occupation reflected in Meath County Council v. Murray [2017] IESC 25, [2018] 1 I.R. 189.

Applying those principles, Kennedy J undertook an independent proportionality assessment and held eviction proportionate, emphasising: confirmed lawful title via vesting order; the public interest in remediating dereliction and allocating social housing through lawful prioritisation; the risk of incentivising self-help occupation; the occupiers’ inability to meet statutory obligations to remediate the derelict site; and the defendants’ failure to join/maintain social housing applications (relevant to the weight of hardship arguments).

3.5 The decision’s practical and doctrinal impact

• Service practice for derelict-site CPOs: local authorities should document “reasonable inquiry” to identify occupants where there is actual occupation. Absent that record, s.6(2) may be unavailable and a court may find formal non-compliance even if notice in fact came to hand.
• But formal defects may not be fatal: the judgment signals that where the affected occupant had actual notice, participated fully, suffered no prejudice, and delayed, the court may refuse to allow defective service to unravel an otherwise completed CPO—particularly when raised defensively after vesting.
• Home rights for unlawful occupiers: the Court reinforces that Article 8 and Article 40.5 can be engaged by factual residence, even if occupation is unlawful. However, once title is established and statutory/public-interest objectives are strong, proportionality may favour eviction.
• Queue-jumping rationale in proportionality: in the social housing context, the Court gave significant weight to the integrity of lawful allocation systems; hardship to unlawful occupants was weighed against the rights of those awaiting allocation and broader public duties under the Act.

4. Complex Concepts Simplified

4.1 What is a vesting order?

A vesting order is the legal instrument by which, after statutory steps (including An Bord Pleanála consent), the local authority acquires the property. Under s.18(2), it vests the property in fee simple, free from other interests, on the “vesting date”.

4.2 “Occupier” vs “owner” under the Derelict Sites Act 1990

“Owner” for CPO notice purposes is tightly defined (s.15(2)). “Occupier” is broader and inclusive; in this case it extended to a person who, as a matter of fact, controlled and lived in the property, even without legal entitlement.

4.3 “Reasonable inquiry” and s.6(2)

If a notice-giver cannot identify a person after reasonable steps, the Act allows generic addressing (“the occupier”). The Court treated “reasonable inquiry” as an evidential question: it must be demonstrated, not assumed.

4.4 Collateral challenge

A collateral challenge is an attempt to undermine a completed administrative/legal act (here, a vesting order) indirectly in later proceedings, rather than by a timely direct challenge (typically judicial review). The Court treated this as especially problematic where the party had notice, participated, and delayed.

4.5 Proportionality in evictions involving a “home”

Even where occupation is unlawful, eviction from a factual home can engage Article 8 ECHR and Article 40.5. Courts must balance the severity of the interference with the legitimacy and necessity of the public authority’s aims, and whether eviction is a proportionate means to achieve those aims.

5. Conclusion

Dublin City Council v O'Reilly and Ors (Approved) [2026] IEHC 309 clarifies two important points for Derelict Sites Act CPO practice and enforcement. First, “occupier” is not confined to lawful occupation: factual control can suffice, requiring careful compliance with statutory service rules and genuine “reasonable inquiry” before resorting to generic service. Second, where defective service caused no prejudice because the occupant had actual notice and actively participated, and where there has been significant delay, the court may treat the CPO and vesting order as unimpeachable and refuse a late defensive attack on title. Finally, while unlawful occupiers may invoke “home” protections, a rigorous proportionality assessment may still strongly favour eviction where dereliction remediation and lawful social housing allocation are at stake.