Merck KGaA & Ors v Merck Sharpe & Dohme Llc & Anor (Approved)

Factual and Procedural Background

The Appellant is a 17-year-old minor who lived with his mother in an apartment rented by her from a housing association (the landlord), an approved housing body and not-for-profit housing charity operating Part 4 tenancies under the Residential Tenancies Act 2004 (“the 2004 Act”). The family was a one-parent household.

In 2023, when the Appellant was 14, his mother (the tenant) was killed in tragic circumstances. Under section 39 of the 2004 Act, a Part 4 tenancy terminates on the death of the tenant unless certain adult family members then residing in the dwelling elect in writing to become the tenant. The statutory list includes, among others, a spouse, cohabitant, adult child (18 or over), and parent. It does not permit succession by a child under 18.

Following the tenant’s death, the landlord took the view that no person qualified to succeed to the tenancy and, in September 2023, sought to terminate it. The Appellant, suing by his aunt and next friend (who had become his legal guardian and was willing to move into the dwelling to care for him), commenced judicial review proceedings. Initially, relief (including certiorari and injunctions) was sought against the landlord directly; that relief was later abandoned, and only a constitutional challenge to section 39 of the 2004 Act proceeded on affidavit evidence. The Appellant has since been living with his maternal grandparents, though the landlord has allowed him to visit and occasionally stay in the former family home. A doctor’s letter exhibited in the High Court described the deprivation of access to the family home as “damaging.”

On 8 November 2023, the High Court granted leave to seek judicial review. In a substantive judgment delivered on 8 July 2024, the High Court refused the Appellant’s claims, holding that he had not shown that section 39 was contrary to Article 40.1 (equality) or any other provision of the Constitution. The High Court also rejected his arguments under Articles 40.3, 40.5, 42A of the Constitution and Article 8 of the European Convention on Human Rights.

The Appellant appealed to the Supreme Court. The Irish Human Rights and Equality Commission (IHREC) was granted liberty to intervene as amicus curiae. At a preliminary stage, the Supreme Court asked the parties to address whether the constitutional challenge ought to have been brought by plenary summons rather than judicial review. By the time of the Supreme Court hearing, the tenancy remained effectively idle pending determination of the proceedings. In the Supreme Court, Judge Donnelly also questioned why the Appellant’s aunt had been joined as a co-applicant where no separate constitutional right of hers was asserted under section 39. All relief claimed in her own right was ultimately refused.

Legal Issues Presented

1. Whether it was appropriate to bring the constitutional challenge to section 39 of the 2004 Act by way of judicial review rather than by plenary summons.
2. To what extent the Appellant’s reliance on Articles 40.3, 40.5 and 42A of the Constitution had been pursued or abandoned in the High Court, and whether he could rely on those arguments on appeal.
3. Whether section 39 of the 2004 Act, insofar as it excludes minor children (under 18) from succeeding to a Part 4 tenancy on a tenant’s death while allowing certain adults (including adult children) to do so, is inconsistent with Article 40.1 (equality) or any other constitutional provision.

Arguments of the Parties

Appellant's Arguments

• Form of proceedings: There is no rigid rule that constitutional challenges must proceed by plenary summons. Judicial review was chosen for reasons of urgency and procedural efficiency, and the essential facts were not in dispute.
• Article 40.1 – Equality:
  • Section 39’s purpose is to provide continuity and stability of housing for households after a tenant’s death. Excluding the class most in need of stability – minor children – is inconsistent with that purpose and lacks a rational connection to it.
  • The section is under-inclusive and arbitrarily distinguishes between minor and adult children of a deceased tenant who were living in the dwelling, particularly disadvantaging children of one-parent families who have no adult in occupation to succeed to the tenancy.
  • In two-parent families, a surviving parent can remain under section 39, whereas in a one-parent family the child is forced to leave, creating unjust and discriminatory outcomes.
  • Articles 40.3, 40.5 and 42A reinforce the equality claim by underscoring the State’s constitutional obligations to protect children, their personal rights, and the home.
• Article 42A – Rights of the Child:
  • Article 42A.1 requires the State, and by extension the courts, to adopt a child-centred approach and to take the rights and best interests of children seriously.
  • Relying on the immigration decision labelled AZ, the Appellant argued that decisions and laws which “seriously affect” children must take account of their rights and best interests; section 39 fails to do so where it deprives bereaved minor children from one-parent families of the possibility of remaining in their home.
  • The unique vulnerability of a bereaved minor child makes the under-inclusive nature of section 39 incompatible with Article 42A.
• Article 40.3 – Personal rights:
  • Article 40.3 protects not only bodily integrity but also the integrity of the human mind and personality. Acute mental distress can itself breach Article 40.3.2.
  • The Appellant’s need to retain his family home is heightened by the mental health impact and emotional harm from the loss of his mother and displacement from the home.
  • The failure of section 39 to protect minor children in single-parent families fails to vindicate their personal and family rights to dignity, stability and a secure family home.
• Article 40.5 – Inviolability of the dwelling:
  • Article 40.5 is said to provide substantive protection for the dwelling and the private enjoyment of the home, not merely procedural safeguards on entry.
  • The Appellant argued that the application of section 39 allows for his eviction, despite his being a lawful occupant, without sufficient procedural safeguards and without a mechanism for him to defend his right to remain in his home.
  • Children in single-parent families are uniquely vulnerable to eviction compared to those in two-parent families; this difference amounts to arbitrary and unequal treatment, supporting the core equality argument.
  • He contended that the strong protections for the home recognised in Damache should apply where he is to be permanently deprived of his home.
• Interaction of rights and standard of review:
  • The interplay between Articles 40.1, 40.3, 40.5 and 42A should inform a stricter standard of scrutiny under the equality guarantee.
  • Even if each of those provisions is not independently breached, their engagement “reinforces” the conclusion that section 39 is unconstitutional due to cumulative deficiencies.

Respondent State's Arguments

• Form of proceedings:
  • Where the primary relief sought is a constitutional declaration of invalidity, the normal, “well-established” and “correct” procedure is plenary proceedings. The present claim should have been brought by plenary summons.
  • The constitutional challenge was only briefly pleaded in the original Statement of Grounds and evolved into the central issue after other relief was abandoned, leaving the evidential basis “rudimentary and evolving.”
  • Proceeding by judicial review hampered exploration of factual matters, such as alternative accommodation arrangements for the Appellant and the wider functioning of the housing and care system, and therefore disadvantaged the Court.
• Article 42A:
  • The Appellant failed to articulate a coherent or particularised basis for saying that Article 42A is engaged by section 39.
  • Reliance on Article 42A, especially the “primary consideration” standard for the child’s best interests, would significantly extend its scope beyond contexts such as child protection or discretionary decision-making, and would be stricter than the test applied in Donnelly.
  • Cases like Re JJ and AZ concerned discretionary administrative decisions rather than direct constitutional challenges to primary legislation and are distinguishable.
• Article 40.3:
  • The Appellant did not have a property right in the dwelling, and his grounds under Article 40.3 were inadequately particularised and unsupported by proper evidence.
  • The Appellant’s suggestion that section 39 operates as a “constitutional tort” against him was rejected.
• Article 40.5:
  • Article 40.5 has a narrow textual base. The Court has previously endorsed an incremental development of its scope and has cautioned against broad expansion beyond its traditional sphere of influence.
  • Key decisions such as McDonagh emphasise that proportionality under Article 40.5 is context-specific and has not been clearly extended to disputes between private entities, particularly where no State body is seeking possession.
  • The Appellant and his guardian have no independent legal interest in the property; tenancies are by nature time-limited occupation rights, and Article 40.5 does not require individualised proportionality review in every private law dispute.
  • Minor children do not have legal autonomy to choose their residence. When a parent’s interest in property terminates, a child has no free-standing constitutional right to remain in that property.
• Article 40.1 – Equality:
  • The appeal rests on a “radical proposition” that treating children differently from adults in relation to property rights violates the Constitution.
  • Age-based distinctions are a routine and legitimate feature of the legal system, including in voting, jury service, benefits, criminal responsibility, and the regulation of harmful products.
  • Article 40.1 expressly allows the State to have due regard to “differences of capacity” when legislating, which encompasses age-related differences.
  • The Appellant’s argument that his legal guardian could take the tenancy on his behalf concedes that some age-based distinctions are legitimate and undermines his equality case.
  • The proper test under Article 40.1 is whether differential treatment is grounded on arbitrary, capricious or irrational considerations. The Appellant and IHREC were said to be seeking to import a Heaney-style proportionality test into equality analysis, contrary to Donnelly.
  • No infringement of other constitutional rights was established; mere “engagement” of those rights cannot justify applying a stricter standard. To hold otherwise would undermine legal certainty and distort the separation of powers by overextending judicial oversight of legislative policy choices.
  • The Legislature rationally drew the line at 18 because minors lack full contractual capacity and because, where parents cannot care for them, the State’s childcare and welfare system lawfully assumes responsibility in a paternalistic manner.
  • Given that Part 4 protections are a significant constraint on landlords’ property rights, section 39(2) is a limited privilege for certain close adult relatives and its scope, including the adult-minor distinction, is rational.

Amicus Curiae (IHREC) Arguments

• Form of proceedings:
  • The Rules of the Superior Courts should not be read as imposing a rigid requirement that constitutional challenges be brought only by plenary action; the right of access to the courts supports flexibility.
  • What matters is whether there is sufficient evidence to address the constitutional issues. No evidential deficiency was apparent in this case.
  • Order 84 rules 22 and 27 empower the court, on its own motion or on application, to direct that judicial review proceedings be brought or continued by way of plenary hearing, preserving flexibility.
• Relevance of other constitutional provisions:
  • Articles 40.3, 40.5 and 42A are relevant both to the appropriate level of scrutiny under Article 40.1 and to the assessment of whether the legislative distinction is constitutionally justifiable.
  • The constitutional provisions must be interpreted harmoniously; the equality guarantee cannot be considered in isolation from provisions protecting the family, children, and the dwelling.
• Article 40.1 – Equality and level of scrutiny:
  • The core constitutional problem is the age-based distinction in section 39(3)(a)(iii), which allows adult children to succeed to a tenancy but excludes minor children, even where both were resident at the tenant’s death.
  • The appropriate comparator for the Appellant is an adult child of a deceased tenant living in the dwelling. Had the Appellant been over 18 at his mother’s death, he would have qualified under section 39.
  • Minor children are a group vulnerable to prejudice and stereotyping and should attract closer judicial scrutiny under the principles in Donnelly.
  • Because a young adult child, who has no rights under Article 42A, enjoys the benefit of section 39 while an older minor child with additional constitutional protection does not, this dichotomy strongly suggests constitutional infirmity.
  • The case does not concern complex fiscal or moral policy choices warranting heightened deference to the Legislature; it concerns the regulation of private tenancies, where the ordinary presumption of constitutionality suffices.
  • Section 39 is intended to mitigate the serious impact of a tenant’s death on co-residing family members by extending security of tenure as of right to specified relatives. Minor children are often those most affected and most in need of stability, yet they are the only close family category completely excluded.
  • IHREC argued there is no absolute bar in Irish law to minors entering residential tenancies, especially where the contract relates to “necessaries,” and highlighted legal analysis suggesting that minors can, in certain circumstances, incur binding obligations for such contracts.
  • This undercuts the State’s reliance on contractual capacity as a complete justification for excluding all minors from succession rights under section 39.

Table of Precedents Cited

Precedent	Rule or Principle Cited For	Application by the Court
Donnelly v Minister for Social Protection [2023] 2 IR 415; [2022] IESC 31	Sets out the modern test under Article 40.1: differential treatment must not be based on arbitrary, capricious or irrational considerations; lists general propositions on presumption of constitutionality, burden of proof, deference, and “suspect” grounds / “categorisations of concern”.	Used as the primary framework for the equality analysis, including the requirement that legislative classifications serve a legitimate purpose and be rationally connected to that purpose; also relied on to justify closer scrutiny where discrimination affects vulnerable groups or intrinsic aspects of personality.
O'Meara v Minister for Social Protection [2024] 1 ILRM 437; [2024] IESC 1	Affirms and applies Donnelly; illustrates under-inclusiveness in legislation affecting children and recognises the equality of children regardless of their parents’ marital status.	Drawn on as a close comparator: the Court analogised the exclusion of the Appellant (a minor child of a deceased lone parent) from section 39’s protection to the under-inclusiveness identified in O'Meara, and followed the remedial approach of declaring inconsistency “insofar as” the provision fails to cover the excluded category.
Galvin v DPP [2020] IECA 319; [2025] IESC 35	Addresses when constitutional issues raised in judicial review should be remitted for plenary hearing; emphasises that constitutional challenges are normally taken by plenary proceedings; discusses the operation of Order 84 rules on converting JR to plenary.	Used to frame the preliminary issue on form of proceedings and to guide the Supreme Court’s assessment of whether it should decide the appeal notwithstanding procedural deficiencies; distinguished because prematurity was not an issue here and the High Court had already ruled substantively.
DP v Governor of the Training Unit [2001] 1 IR 492; [2000] IEHC 104	Holds that the rule now in Order 27(5) (Order 84) can be engaged at the leave stage, allowing the court to refuse JR relief and direct that matters proceed by plenary summons where appropriate.	Relied on to support the view that courts can, at any point including an early stage, direct that proceedings “continue as if they had been begun by plenary summons,” underscoring the High Court’s capacity to require plenary procedure for constitutional challenges.
SM v Ireland [2007] 3 IR 283; [2007] IESC 11	States that where there is an underlying administrative or judicial decision under challenge in JR, a constitutional challenge to enabling legislation can sometimes be “tacked on.”	Cited to show that the “tack on” principle must be treated with caution and that, once the challenge to the administrative decision was abandoned here, there was no longer an underlying decision to which the constitutional claim could be attached.
Riordan v An Taoiseach (No. 2) [1999] 4 IR 343	Indicates that where the main relief sought is a constitutional declaration, proceedings should typically be brought by plenary summons.	Relied on by the State to argue that the present constitutional challenge ought to have been framed as a plenary action rather than judicial review.
Lough Swilly Shellfish Growers Co-Op Society Ltd v Bradley [2013] 1 IR 227; [2013] IESC 16	Describes a spectrum of situations in which new arguments may be advanced on appeal and when it is inappropriate to raise entirely new issues or evidence.	Used to assess whether the Appellant’s reliance on Articles 40.3, 40.5 and 42A on appeal went beyond what had been argued below. The Court concluded the arguments were within permissible bounds and not abandoned in the High Court.
Gilchrist v Sunday Newspapers Ltd [2017] 2 IR 284; [2017] IESC 18	States that the Constitution is intended to function harmoniously; fundamental rights provisions must be interpreted in their overall constitutional context.	Invoked to justify considering Articles 40.3, 40.5, and 42A together with Article 40.1, and to support an integrated approach to equality analysis informed by other rights.
NVH v Minister for Justice and Equality [2018] 1 IR 246; [2017] IESC 35	Links the right to work with dignity and freedom, and applies Article 40.1 to prevent an absolute denial of certain rights to non-citizens.	Cited as an example of reading equality rights in light of human dignity and other constitutional values, illustrating how substantive rights can inform the scope of equality guarantees.
Heaney v Ireland [1996] 1 IR 580	Establishes the proportionality test for restrictions on constitutional rights.	Referred to as a contrast with Article 40.1 analysis: while proportionality may be central where a specific right is directly infringed, equality analysis under Donnelly has its own structure, though other rights may inform it.
Re JB and KB (Minors) [2019] 1 IR 270; [2018] IESC 30	Describes Article 42A as having been introduced to ensure the Constitution is more clearly “child-centred.”	Used to support the proposition that Article 42A changed the constitutional posture towards children and that courts must treat children as specific holders of rights.
Re JJ [2022] 3 IR 1; [2021] IESC 1	Characterises Article 42A.1 as a recalibration of emphasis rather than substance in child and family matters, making explicit what was implicit but still significant for interpretation.	Relied on to support the view that Article 42A.1 affects how courts should interpret and apply equality guarantees where children’s interests are engaged.
The Child and Family Agency v McD and Ors [2024] 2 ILRM 153; [2024] IESC 6	Notes that Article 42A imposes a specific obligation on courts to consider the best interests of each child.	Cited to emphasise that child-centric considerations are constitutionally required in matters affecting children, even if the case at hand is not a child-care proceeding.
The People (DPP) v CC [2025] IESC 11; The People (DPP) v PB [2025] IESC 12; DOE v DPP [2025] IESC 17	These criminal cases recognise that Article 42A, although primarily concerned with care and adoption, expressly acknowledges the status of childhood.	Used to support the view that Article 42A’s recognition of childhood has broader implications across legal contexts, including equality analysis involving minors.
AZ, MZ and CZ v Minister for Justice and Equality [2024] IESC 35	Holds that Article 42A.1 is of general application: the rights and welfare of an Irish citizen child must be considered in deportation decisions that may seriously affect the child.	Relied on by the Appellant to argue that section 39 must be assessed with reference to Article 42A as well as Article 40.1; the Court accepted that Article 42A.1 has broad relevance but focused its effect within the equality analysis.
Kinsella v Governor of Mountjoy Prison [2012] 1 IR 467; [2011] IEHC 235	States that Article 40.3 protects the integrity of the human mind and personality, not just the body.	Cited by the Appellant to support an argument that the emotional and psychological harm he suffered engages Article 40.3; the Court ultimately found the Article 40.3 claim underdeveloped and factually unsupported.
Sullivan v Boylan (No. 2) [2013] 1 IR 510; [2013] IEHC 104	Suggests that acute mental distress can itself constitute a breach of Article 40.3.2°.	Relied on by the Appellant in support of his mental health–based argument under Article 40.3; the Court declined to find a breach on the evidence available.
Damache v DPP [2012] 2 IR 266; [2012] IESC 11	Establishes strong procedural and substantive safeguards for the protection of the dwelling under Article 40.5, especially in the context of search warrants.	Cited by the Appellant as an example of the level of protection Article 40.5 requires; the Court distinguished the present private tenancy context and did not extend Damache’s approach to confer a separate right of minor occupants to remain in private dwellings after the parent’s tenancy ends.
Meath County Council v Murray [2018] 1 IR 189; [2017] IESC 25	Offers a more restrained interpretation of Damache; advocates incremental development of Article 40.5 and notes the limited textual base of the provision.	Relied on by the State to argue against a wide expansion of Article 40.5 to cover disputes like the present one between private parties.
Clare County Council v McDonagh [2022] 2 IR 122; [2022] IESC 2	Important pronouncement on Article 40.5, recognising contextual proportionality where a public authority seeks possession, but limiting its application, particularly noting distinctions with private landowners.	Used by the State to argue that Article 40.5’s proportionality requirements in public law possession proceedings do not straightforwardly apply to private landlord–tenant disputes.
Pepper Finance Corporation v Persons Unknown [2022] IECA 170; [2023] 1 ILRM 381; [2023] IESC 21	In the Court of Appeal, obiter remarks suggested proportionality does not arise in disputes between private entities; the Supreme Court did not express a concluded view on that specific point.	Cited to illustrate the unresolved and limited scope of Article 40.5 in purely private law possession disputes, supporting the Court’s reluctance to treat Article 40.5 as a standalone basis to invalidate section 39.
The People (DPP) v O'Shea [1982] IR 384	Confirms that constitutional provisions must be read together and not in isolation.	Supports the Court’s approach of reading Article 40.1 in harmony with other fundamental rights provisions, including Articles 40.3, 40.5 and 42A.
Heneghan v Minister for Housing, Planning and Local Government [2022] 1 ILRM 323; [2022] IESC 7	Applies and reaffirms the principles from Donnelly on equality and the level of scrutiny, even in areas such as taxation and welfare.	Cited to confirm that closer scrutiny may be appropriate where a classification concerns a “categorisation of concern,” even in fields normally attracting deference, and to underline that constitutional provisions should be interpreted coherently.
X v Minister for Social Protection [2021] 3 IR 528; [2019] IESC 82	Notes the analytical difficulties inherent in Article 40.1 challenges and stresses the importance of avoiding both over- and under-scrutiny of legislative classifications.	Referenced to frame the Court’s approach to balancing deference and scrutiny in equality analysis.
BM and JM v Chief Appeals Officer and Others [2024] IESC 51	Reaffirms the general propositions on equality set out in Donnelly.	Cited as part of the line of authority confirming the governing Article 40.1 test.
In Re The Employment Equality Bill, 1996 [1997] 2 IR 321; [1997] IESC 6	States that age-based discrimination is in a “different constitutional category” from grounds such as sex or race but affirms that “the aged” and “the young” are protected against arbitrary or irrational discrimination.	Used to discuss the status of age as a ground of differentiation, and to support the conclusion that, especially after the insertion of Article 42A, age in respect of children can be a ground warranting closer scrutiny.
MG v Director of Oberstown Children Detention Centre [2019] IEHC 275	Discusses deference to legislative choices in distinguishing between children and adults, while emphasising that such deference is not unlimited and must still respect other constitutional rights.	Cited to illustrate that differences in capacity may justify differential treatment in some contexts (e.g. order measures in detention), but also that not every age-based difference is automatically justified.
de Búrca v Attorney General [1976] IR 38	Articulates that Article 40.1 embodies the Aristotelian principle that justice requires treating equals equally and unequals unequally.	Relied on to explain that differences in capacity (such as age) must be relevantly related to the differential treatment; they do not eliminate the need for equality analysis.
Landers v Attorney General [1975] 109 ILTR 1	Involves age-based restrictions designed to protect children (e.g., from exploitation on licensed premises).	Cited as an example where age distinctions concerning children are plainly protective and thus likely to satisfy equality requirements, contrasting with the exclusionary effect of section 39 on minors.
B (A Minor) v Director of Oberstown Children Detention Centre [2023] 2 IR 191; [2020] IESC 18	Recognises a constitutional imperative to protect children in the context of detention, illustrating heightened protection owed to minors.	Used to support the concept that, in some contexts, the Constitution may require treating children differently from adults to provide them with greater protection.
Cox v Ireland [1992] 2 IR 503	Criticises legislative schemes that are “impermissibly wide and indiscriminate” in their impact on constitutional rights.	The Court adopts this language by analogy to describe the breadth of section 39’s exclusion of all minor children from succession rights as arbitrary and irrational in the specific context of the Act.
Residential Tenancies Tribunal decision: Dunne (deceased) & Another v Murnin (TR1115-001449, 2 February 2016)	Suggests that the election in writing to become a tenant under section 39 must be made before any application to the Residential Tenancies Board; initiating dispute resolution does not itself count as written notification.	Cited via commentary to illustrate a practical feature of section 39—no express time limit for the election but a requirement of written notice separate from recourse to dispute resolution.

Court's Reasoning and Analysis

1. Form of Proceedings: Judicial Review vs Plenary Action

Judge Donnelly began by addressing whether the constitutional challenge ought to have been brought by judicial review or plenary proceedings. Citing case law and Order 84 of the Rules of the Superior Courts, she noted that:

• The “normal” and “well-established” procedure for challenges to the validity of legislation is by plenary action, not judicial review.
• Order 84 rules 22 and 27 give courts power, including on their own motion, to direct that proceedings be commenced or continued as if begun by plenary summons whenever appropriate, including at an early stage.
• The High Court was critical of the choice of procedure but nonetheless proceeded to hear the constitutional challenge in JR form, without any motion or cross-appeal seeking remittal to plenary.

Judge Donnelly concluded that, in principle, the constitutional challenge ought to have been heard by way of plenary proceedings, especially once the challenge to the landlord’s decision fell away and only the abstract constitutional challenge remained. However, in the specific circumstances—no pleaded objection by the State at an early stage, no motion to remit, a full substantive High Court judgment already delivered, the tenancy lying idle, and full argument having been heard in the Supreme Court—she held that it was appropriate and necessary for the Supreme Court to determine the appeal on its merits. She thus proceeded to decide the substantive constitutional issues while noting that, as a general rule, constitutional challenges should normally be brought by plenary action and that the burden lies on any applicant proceeding by judicial review to justify that procedural choice.

She further observed that there was no sound reason for the Appellant’s aunt to have been joined as a co-applicant, as no separate constitutional right of hers under section 39 had been identified. All relief in her own name was therefore refused, and subsequent references to “the Appellant” in the judgment refer only to the minor.

2. Scope of Issues on Appeal: Articles 40.3, 40.5 and 42A

The Court reviewed whether the Appellant had abandoned his non-equality grounds (Articles 40.3, 40.5, 42A) in the High Court, given that the High Court judge described them as “deprioritised.” Applying the principles in Lough Swilly Shellfish, Judge Donnelly held:

• The Appellant had not abandoned those grounds; he simply relied on his written submissions rather than extensive oral argument.
• No new evidence was adduced on appeal, and any further elaboration of legal argument fell within the permissible range for appellate advocacy.

Accordingly, the Appellant was entitled to rely on Articles 40.3, 40.5 and 42A on appeal, but the Court examined first whether those provisions were independently breached before subsuming them within the Article 40.1 analysis.

3. Article 42A.1 – Recognition of the Status of Childhood

Judge Donnelly surveyed the case law on Article 42A.1 and concluded that it represents a constitutional recognition of the status of childhood and a shift of emphasis towards treating children as specific holders of rights. She reasoned that:

• Although many leading decisions on Article 42A involve child care, adoption or immigration, their dicta confirm that courts must take a “child-centric” approach in matters concerning children.
• Article 42A.1 is not confined to administrative decision-making; it is also relevant when assessing whether legislation sufficiently respects and vindicates constitutional rights, including equality.
• The importance of Article 42A.1 in this case lies not in creating a freestanding best-interests test for legislation, but in its effect on how Article 40.1 is to be applied where children are expressly excluded from legislative benefits.

The Court thus saw Article 42A.1 as a key contextual factor justifying heightened attention to the impact of section 39 on minor children in the equality analysis.

4. Article 40.3 – Personal Rights

Turning to Article 40.3, the Court accepted in principle that personal rights include mental integrity and that acute mental distress can, in some circumstances, amount to a constitutional breach. However, in this case:

• The Appellant’s Article 40.3 arguments were described as underdeveloped in law and insufficiently supported in fact.
• The medical evidence relied on—a doctor’s letter—was hearsay and, even on its face, did not state that it was in the Appellant’s best interests for him or his guardian to remain in the property.
• The Appellant had no independent property right in the apartment.

In the absence of a properly grounded and particularised claim, the Court declined to find any violation of Article 40.3. Nonetheless, the Court accepted that the nature of personal rights protected by Article 40.3 could inform the equality analysis under Article 40.1.

5. Article 40.5 – Inviolability of the Dwelling

On Article 40.5, Judge Donnelly acknowledged the importance of the dwelling in constitutional terms but rejected the Appellant’s contention that this provision conferred on him a standalone right to remain in the property after his mother’s tenancy ended. Her key points were:

• Article 40.5 protects the inviolability of the dwelling, but the jurisprudence has developed incrementally and is constrained by a narrow textual base.
• Nothing in the authorities cited established that the termination of a parent’s tenancy in a private law landlord–tenant relationship automatically gives a child a distinct constitutional right to remain in the dwelling.
• If Article 40.5 were interpreted to give minor occupants a separate right to continued occupancy each time a parent or guardian’s tenancy or possessory right ended, it would “upend” the legal framework governing private residential property disputes.
• The Court expressly left open the question whether different considerations might apply where a public body is the decision-maker in possession proceedings.

Therefore, the Court held that the Appellant had not established a breach of Article 40.5 on the arguments made. At the same time, it recognised Article 40.5 as an important constitutional statement regarding the security of the home and stated that it must be taken into account in the Article 40.1 analysis.

6. Article 40.1 – Equality: Framework and Object of the Legislation

Judge Donnelly then turned to the core question under Article 40.1. She adopted the analytical framework from Donnelly and O'Meara, emphasising:

• The need to avoid both “oversimplified justification” that would shield almost all legislation from challenge and excessively demanding scrutiny that nearly no law could survive.
• The presumption of constitutionality, the Legislature’s policy-making role, and the intent behind allowing due regard to differences of capacity and social function.

She identified the primary objective of the 2004 Act, from its Long Title, as providing “a measure of security of tenure for tenants of certain dwellings” in accordance with the exigencies of the common good, together with clarifying rights and obligations and providing a dispute-resolution framework. Part 4 achieves security of tenure by limiting termination to specified grounds. Section 39 furthers that objective by extending security of tenure beyond the tenant’s death to specified family members resident in the dwelling, on terms that respect landlords’ economic interests by requiring the successor to assume the tenancy obligations.

Judge Donnelly underscored that security of tenure is intimately connected with constitutional values: it supports the peaceful enjoyment of the dwelling, community life, educational and social stability for children, and arrangements for care of vulnerable family members. This sits comfortably with the Preamble’s emphasis on the common good, the dignity and freedom of the individual, and the protection of family and dwelling-related interests under Articles 40.3, 40.5 and 42A.

7. Comparator and Nature of the Classification

The Court determined that the relevant comparator for the Appellant is a child of the deceased tenant who is 18 or over and was living in the dwelling at the time of the tenant’s death. Both the Appellant and such an adult child share two critical characteristics: they are offspring of the deceased tenant and residents of the dwelling at the relevant time. Yet only the adult child can avail of section 39’s succession mechanism; the minor child is wholly excluded.

The classification is therefore based primarily on age. Judge Donnelly analysed whether age, in this context, should be regarded as a ground warranting closer scrutiny (“categorisation of concern”) under Article 40.1. She reasoned that:

• Age is intrinsic to a person and immutable at a given moment, akin in that respect to other characteristics that have been recognised as capable of attracting closer scrutiny.
• While earlier case law drew distinctions between age and grounds like sex or race, those decisions pre-dated Article 42A. After the constitutional recognition of childhood, age-based distinctions affecting children must be examined in that light.
• Children, particularly teenagers and those at the extremes of age, constitute a vulnerable group; vulnerability itself—rather than proof of actual prejudice or stereotyping in a given case—can justify closer scrutiny.
• Article 42A.1 expressly recognises “the natural and imprescriptible rights of all children” and indicates that children are the only group whose rights are thus specifically named, reinforcing the need for particular vigilance regarding legislative classifications affecting them.

The Court considered and rejected the State’s contention that the phrase in Article 40.1 allowing the State to have “due regard to differences of capacity” should be treated as effectively dispositive whenever minors are treated differently from adults. Instead, Judge Donnelly held that:

• Claims of differing capacity cannot short-circuit the equality inquiry; they must be assessed only after determining the applicable level of scrutiny.
• Differences in capacity may justify differential treatment where the distinction is relevant and rational (for example, protective measures for children), but they do not give the State unlimited licence to exclude children from legislative benefits conferred on adults.

In light of Article 42A.1, the immutability of age at any given time, and the clear vulnerability of minor children—especially those in one-parent families who lose their sole parent—the Court concluded that the age-based distinction in section 39, which expressly excludes all children under 18 from benefits extended to adult children, must be subjected to a close level of judicial scrutiny.

8. Application of Close Scrutiny to Section 39

Applying close scrutiny, the Court examined whether excluding minor children is rationally related to the purposes of the Act and to legitimate State interests, particularly landlords’ property rights and minors’ purported lack of contractual capacity.

(a) Contractual capacity and minors

The State argued that minors lack full contractual capacity and that landlords’ ability to enforce tenancy obligations against them would be uncertain, justifying the adult–minor distinction. IHREC, however, highlighted that the common law allows minors to enter into binding contracts for “necessaries” (including housing) and that minors can in some circumstances acquire property interests and be bound unless they avoid the contract. Judge Donnelly reasoned that:

• Irish law recognises gradations of capacity and, in many contexts, varying age thresholds for different rights and obligations; there is no absolute barrier to minors being parties to tenancy-like obligations.
• Given that the Legislature recognised capacity in minors to enter contracts for necessaries, the complete omission of any mechanism to address the situation of bereaved minor children under 18—when adult children in the same position are fully protected—suggests arbitrariness rather than a reasoned response to capacity concerns.

(b) Treatment of adults lacking capacity

Judge Donnelly also considered that section 39 makes no special provision for adult family members who lack capacity. In practice, any such adult could be assisted by a decision-making representative under the Assisted Decision-Making (Capacity) Act 2015, who might enter into the tenancy on their behalf. Thus, an adult child without capacity can, in effect, be accommodated within the existing scheme, whereas a minor child—who may have both legal capacity (as to necessaries) and factual capacity to fulfil tenancy obligations—cannot succeed to the tenancy under any circumstances.

This contrast further underlined, in the Court’s view, that the exclusion of minors is not a carefully tailored response to capacity issues but an undifferentiated and sweeping omission.

(c) Landlords’ property rights

The State emphasised landlords’ property rights as a justification for limiting succession. Judge Donnelly rejected this as persuasive in the specific context of section 39:

• By allowing spouses, cohabitants, adult children, and parents to elect to continue the tenancy, the Oireachtas has already accepted a substantial interference with landlords’ rights of re-entry to regain physical possession, balancing that against security of tenure for families.
• From the landlord’s perspective, what matters most is the enforceability of the tenancy obligations (including rent), not the age or identity of the successor per se. A 14‑year‑old child who has lived in the dwelling for many years may be better known to the landlord than a newly arrived adult relative.
• Landlords’ economic interests are preserved if any successor—adult or minor with appropriate legal mechanisms—assumes the tenancy on the same terms and conditions, subject to the landlord’s existing rights under the Act in cases of non-compliance.

The Court therefore held that the focus on landlords’ rights did not rationally justify excluding all minors from succession when adult relatives are allowed to succeed under the same statutory scheme.

(d) Failure to consider calibrated solutions for minors

Judge Donnelly stressed that an applicant challenging under-inclusiveness is not required to draft the legislation himself. Nevertheless, she observed that several potential mechanisms might have addressed minors’ situations, such as:

• Recognising older minors as having capacity to enter into tenancy agreements in certain circumstances;
• Allowing a legal guardian or trustee, possibly with court oversight, to enter into or continue the tenancy on the minor’s behalf;
• Designing a gradated system of capacity for children of different ages.

The Legislature had not attempted any such calibrated approach. Instead, it drew an absolute line at 18, conferring succession rights only on adult children and ignoring the vulnerabilities of minor children, particularly those in one-parent families who lose their sole tenant parent. In the Court’s view, this sweeping exclusion, in a context where the Act’s central purpose is to secure stable housing for families in the common good, “smacks of arbitrariness.”

9. Overall Equality Conclusion

Drawing these strands together, Judge Donnelly concluded that:

• Section 39, read in the context of the 2004 Act’s objective of security of tenure, the constitutional importance of the dwelling (Article 40.5), the personal rights of family members (Article 40.3) and the recognition of the status of childhood (Article 42A.1), creates an unjustifiable and arbitrary disparity between adult and minor children.
• The exclusion of all children under 18 from the opportunity to succeed to a tenancy, while granting full protection to adult children in the same factual position, is “impermissibly wide and indiscriminate” in the sense used in Cox v Ireland.
• Minor children constitute a vulnerable group; those in one-parent families who lose that parent are particularly vulnerable. Yet the legislation makes “no provision whatsoever” for the possibility that such children might remain securely in their home.
• In these circumstances, the distinction between minor and adult children in section 39 is arbitrary and irrational when viewed objectively in light of the social function of the legislation and the constitutional recognition of childhood.

Accordingly, the Court held that section 39 is inconsistent with Article 40.1 of the Constitution insofar as it excludes minor children like the Appellant from succession rights.

10. Remedy

The Court characterised the defect as one of under-inclusiveness: the statute grants a benefit (succession to a Part 4 tenancy) to a defined class (including adult children) but unconstitutionally fails to extend that benefit to similarly situated minor children. Following the approach taken in O'Meara, the Court determined that the appropriate remedy was a declaration that section 39 is inconsistent with the Constitution to the extent of this under-inclusiveness. It noted:

• This declaration does not itself create a detailed statutory framework for minors; further legislative action is required to specify how minor children may succeed to tenancies consistently with constitutional requirements.
• The Appellant had pleaded damages but did not pursue that relief in submissions; the Court therefore focused on declaratory relief.

Holding and Implications

Holding: The Supreme Court (in this judgment) held that section 39 of the Residential Tenancies Act 2004 is inconsistent with Article 40.1 of the Constitution insofar as it does not extend to the Appellant, a child under the age of 18 years, and to similarly situated minor children. A declaration of inconsistency to that effect is made. The Court found no independent breach of Articles 40.3 or 40.5 on the arguments and evidence advanced, though those provisions informed the equality analysis. Article 42A.1 was treated as an important contextual provision recognising the status and rights of children.

On the procedural issue, the Court held that constitutional challenges to the validity of legislation should normally be brought by plenary summons. Judicial review is an exceptional route for such challenges, and applicants who choose it bear the burden of demonstrating that it is appropriate in the circumstances. Nevertheless, in this case the Court proceeded to determine the merits, given the progress of the litigation and the sufficiency of the evidential record.

All relief sought by the Appellant’s aunt in her own right was refused, as no violation of any constitutional right personal to her had been established.

Implications:

• For the parties: The declaration of inconsistency removes the constitutional barrier that prevented the Appellant, as a minor child of the deceased tenant who lived in the dwelling, from being treated on an equal footing with adult children for the purposes of succession under section 39. Any further detailed remedy or mechanism by which he (or other minors in similar situations) may actually succeed to the tenancy is left to the Legislature.
• For legislation and policy: The judgment clarifies that laws which confer benefits on adult children but expressly exclude minor children solely on age, particularly where they concern the security of the home and follow the death of a parent, are subject to close scrutiny in light of Article 42A and may be found unconstitutional if the exclusion is arbitrary or insufficiently justified.
• For equality jurisprudence: The decision elaborates on the Article 40.1 framework post‑Donnelly and O'Meara, confirming that:
  • Age, in the context of children, can function as a “categorisation of concern” warranting heightened scrutiny;
  • Article 42A.1 meaningfully influences equality analysis where children’s interests are engaged;
  • Differences in capacity cannot be invoked in a way that short-circuits or reverses the required equality analysis.
• For procedural practice: The Court reinforces the principle that plenary proceedings are the norm for constitutional challenges, and that High Court judges should consider at an early stage whether cases commenced by judicial review ought to be converted or remitted for plenary hearing when constitutional validity of legislation is in issue.
• Precedential effect: The decision primarily affects statutory schemes that differentiate between adult and minor children in the conferral of housing security benefits following a tenant’s death. It signals that any such schemes must be carefully justified and structured to reflect children’s constitutional status and vulnerabilities. The opinion does not purport to set a general new test outside the established Donnelly/O'Meara framework but applies that framework in light of Article 42A.