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

Factual and Procedural Background

The proceedings concern a constitutional challenge to section 39(3)(a) of the Residential Tenancies Act 2004 (as amended), which governs statutory succession to so‑called “Part 4” residential tenancies following the death of a tenant.

The Minor Appellant is a boy who lived with his late mother as a one‑parent family in an apartment rented from Company A, a non‑profit approved housing body providing social housing funded by local authorities. The mother was the sole tenant and the Minor Appellant was recorded as a permitted occupant. After more than 11 years seeking housing, she obtained the tenancy in June 2022. In 2023 she died in tragic and violent circumstances while on holiday abroad, when the Minor Appellant was about 14–15 years of age.

Following his mother’s death, the Minor Appellant initially went to live with his grandparents. At first it appears that the grandparents were considered as potential successors to the tenancy. Subsequently, the family proposed that the Minor Appellant’s aunt (the First Appellant)—who lived nearby, had a good relationship with him, and intended to seek guardianship—would surrender her own accommodation and move into the apartment with him. However, the First Appellant had not been assessed as having a housing need, had not resided in the apartment for the required period, and therefore did not qualify under either Company A’s internal succession policy or under s.39(3)(a). That statutory provision allows succession only to certain close family members (spouse, civil partner, qualifying cohabitant, child over 18, or parent) who were living in the dwelling at the date of death and who elect in writing to become tenants.

Company A indicated that it proposed to recover possession of the apartment. In response, the Appellants commenced judicial review proceedings. They initially sought wide‑ranging reliefs, including:

• An injunction preventing recovery of possession;
• Orders quashing Company A’s decision to seek possession and its determination that the First Appellant had no housing need;
• Declarations that s.39 of the 2004 Act is repugnant to the Constitution and incompatible with the European Convention on Human Rights (ECHR).

By the time of the High Court hearing, the Appellants had:

• Abandoned any claim against Company A;
• Ceased to rely on the ECHR;
• Limited the proceedings to a constitutional challenge against The State to the validity of s.39(3)(a) on the ground that it is unconstitutionally underinclusive because it does not permit the First Appellant to succeed to the tenancy so that the Minor Appellant can continue to reside in the apartment.

The High Court determined the substantive constitutional question and rejected the challenge. The Appellants obtained leave to appeal to the Supreme Court.

On appeal, a preliminary issue arose as to whether judicial review is the appropriate procedural vehicle for a direct challenge to the constitutionality of primary legislation. While the Respondent State maintained that such challenges should proceed by plenary summons, it accepted that the core constitutional issue had already been decided in the High Court and should be dealt with by the Supreme Court in this appeal. The Court therefore proceeded to address the merits, while also giving general guidance on the proper form of proceedings for future constitutional challenges.

Legal Issues Presented

1. Whether section 39(3)(a) of the Residential Tenancies Act 2004, which permits certain adults (including adult children) but not minor children to succeed to a Part 4 tenancy on the death of a tenant, is repugnant to Article 40.1 of the Constitution on the grounds that:
   • It indirectly discriminates against children in single‑parent families by reference to parental marital or family status; and/or
   • It directly discriminates on the basis of age by excluding children under 18 from statutory succession.
2. Whether Article 42A (recognising the “natural and imprescriptible rights of all children” and requiring the State, as far as practicable, to protect and vindicate those rights) obliges the Oireachtas to provide for succession by minor children (or an adult carer) to a Part 4 tenancy, and whether s.39(3)(a) is inconsistent with that Article.
3. Whether Article 40.5 (the inviolability of the dwelling) renders s.39(3)(a) unconstitutional insofar as it does not allow minor occupants or their relatives to succeed to a tenancy and thereby may lead to loss of occupation of a dwelling following the tenant’s death.
4. Whether, when assessing alleged age‑based discrimination under Article 40.1, distinctions based on the line between minority and adulthood constitute a “suspect” classification requiring close or strict scrutiny, or are instead to be reviewed on a rationality standard.
5. Whether s.39(3)(a) is unconstitutionally “underinclusive” in the sense used in equality jurisprudence, and, if so, what the appropriate constitutional remedy would be.
6. Procedurally, whether a direct challenge to the constitutional validity of primary legislation should ordinarily be brought by way of plenary proceedings rather than judicial review.

Arguments of the Parties

Appellants' Arguments

• The Appellants did not seek to invalidate s.39(3) in its entirety or to remove any of the categories already entitled to succeed. Instead, they contended that the provision is unconstitutionally underinclusive because it fails to extend the benefit of statutory succession to them, in particular to the First Appellant, so that she could become the tenant and permit the Minor Appellant to remain in the apartment.
• They argued that, although s.39(3)(a) appears neutral on its face, its practical effect is to discriminate against children in single‑parent families. A child in a two‑parent household, or where a surviving parent has a spouse/partner/cohabitant resident in the dwelling, would often be able to remain because that adult could succeed to the tenancy under s.39(3)(a). By contrast, a child in a comparable one‑parent family, such as the Minor Appellant, cannot remain if there is no qualifying adult resident at the time of death.
• On this analysis, the comparator is a child of a married couple (or equivalent family unit) aged 14–15, otherwise identically situated to the Minor Appellant, who could remain in the tenancy when one parent dies and the other succeeds to the tenancy, whereas the Minor Appellant cannot. The Appellants relied on the Supreme Court’s decision in O’Meara v Minister for Social Protection to support the contention that the Constitution prohibits discrimination based on parental marital or family status and the derivative status of the child.
• They contended that this indirect discrimination on the basis of parental status and family structure offends Article 40.1 and can only be cured by recognising a right of the First Appellant to succeed to the tenancy, thereby remedying the underinclusivity.
• Although the Appellants referred to Article 42A and Article 40.5, their primary focus remained on Article 40.1 and on the claimed underinclusive nature of s.39(3)(a), framed as a relatively modest request to extend the existing statutory scheme rather than to dismantle it.

Amicus Curiae (Company B) Submissions

• Company B, as amicus curiae, advanced a markedly different equality argument. It submitted that s.39(3)(a) gives rise to a direct, facial discrimination on the basis of age, because a child, stepchild, foster child or adopted child who is aged 18 or more can succeed to the tenancy, while a child in precisely the same position but under 18 cannot.
• Company B argued that age should be treated as a “suspect” ground for the purposes of Article 40.1, particularly where the distinction is between children and adults, because children are a vulnerable group and thus especially prone to prejudice or stereotyping. On this basis, the Court should apply a high level of scrutiny.
• Even if age were not deemed a suspect ground, Company B contended that the exclusion of minor children from succession fails even a rationality test. Of all members of a tenant’s household, minor children are typically the most vulnerable and in need of protection, yet they are the one category categorically excluded from statutory succession while other adults (partners, cohabitants of only six months’ residence, parents, and adult children) may benefit.
• Company B submitted that it is both conceptually and practically possible for minors to hold tenancies. It referred to the common law position, as summarised in legal authorities, that:
  • Contracts by minors involving interests in property of a permanent nature with ongoing obligations are voidable rather than void; and
  • A lease taken by an “infant” (minor) is voidable at the minor’s option on or within a reasonable time after attaining majority, but binding until repudiated, with liability to pay for use and enjoyment where appropriate.
  On that basis, it argued that the Oireachtas could feasibly provide for Part 4 tenancies in favour of minors as successors.
• On Company B’s approach, the proper comparator is an adult child of the deceased tenant (or the same individual when aged 18 rather than 14–15). Because the statute treats these comparators differently solely on the basis of age, the inequality should be held unconstitutional. The appropriate constitutional remedy, it suggested, would be to allow minor children themselves to succeed to the statutory tenancy.
• Company B acknowledged a tension between its approach and that of the Appellants as to who should become tenant (the First Appellant or the Minor Appellant), but suggested that both strands could be seen as different ways of addressing the same underlying underinclusivity problem, leaving it to the Oireachtas to choose the precise adjustment.

Respondent State's Arguments

• The Respondent State disputed that s.39(3)(a) discriminates on the basis of parental marital status or family structure. The statutory line is drawn not by reference to whether a child’s parents are married, cohabiting, or separated, but by reference to whether a qualifying adult (spouse, civil partner, cohabitant, parent, or adult child) resided in the dwelling at the time of the tenant’s death and elects to succeed.
• On that footing, the same difference in outcome (a minor being able to remain or having to leave) would occur where:
  • A non‑parent cohabitant, spouse, or civil partner resides in the premises and succeeds to the tenancy;
  • A parent of the deceased tenant succeeds; or
  • Another child over 18 succeeds.
  Thus, the decisive factor is the presence of any qualifying adult occupier, not the marital status of the Minor Appellant’s parents.
• The Respondent State accepted that s.39(3)(a) differentiates on the basis of age but argued that distinctions between minors and adults are commonplace in Irish law, including in contract and tenancy law, and are expressly recognised in the Constitution itself (for example in the provisions governing voting and eligibility for office, and in the Court’s jurisprudence on the age‑limited right to education). Age 18 is one of the most familiar legal thresholds, including under the Age of Majority Act 1985.
• The State submitted that age, particularly the minority/adulthood distinction, is not a “suspect” classification requiring strict scrutiny under Article 40.1. Instead, the correct test is whether the classification is arbitrary, capricious or irrational, having regard to the legislative objective, as set out in the Court’s jurisprudence (including Donnelly v Minister for Social Protection and related authority).
• According to the Respondent State, the objective of Part 4 of the 2004 Act is to confer substantial security of tenure on tenants while striking an appropriate balance with landlords’ property rights. Section 39(1) implements the traditional rule that a tenancy terminates on the tenant’s death, while s.39(3) creates an exceptional statutory privilege for a narrow class of co‑occupying adult relatives to succeed to the tenancy. Limiting this exceptional privilege to adults is, the State argued, both rational and consistent with long‑standing legal principles on minors’ contractual capacity and lack of autonomy over where they live.
• The State emphasised that children, as a matter of fact and law, generally do not choose where they reside; they are required to live with parents or guardians and may have to move if the adult’s circumstances change or the adult dies. The statute’s approach—making a child’s ability to remain in a dwelling contingent on an adult tenant’s status and decisions—reflects that reality.
• The Respondent State also pointed out that neither the Appellants nor Company B had clearly identified a constitutionally sound and workable alternative scheme that:
  • Would extend the benefit to the Minor Appellant; and
  • Would not itself generate new inequalities or constitutional objections.
  The State argued that this difficulty in defining a viable alternative tended to confirm that the existing legislative line is at least rational.
• On Article 42A, the State contended that the provision is primarily aimed at recalibrating the balance between parental and children’s rights in areas such as care, custody and adoption. Article 42A.1 is declaratory in nature and does not create any specific “natural and imprescriptible” right of a child (or adult) to reside indefinitely in a particular dwelling against the wishes of its lawful owner.
• On Article 40.5, the State relied on the Supreme Court’s established jurisprudence, in particular Meath County Council v Murray, to argue that the Article chiefly prohibits forcible or unlawful entry into a dwelling. Section 39(3) does not itself authorise entry: it simply defines when a statutory tenancy continues; any subsequent re‑entry by the landlord would be an exercise of the landlord’s lawful property rights following termination. The State contended that using Article 40.5 to invalidate s.39(3) would radically destabilise landlord‑and‑tenant law.
• On procedure, the State maintained that a direct constitutional challenge to primary legislation, which enjoys a presumption of constitutionality, should normally be brought by plenary summons, so that issues of fact can be fully explored by oral evidence, discovery, and related mechanisms. While accepting that this particular appeal should not fail for procedural reasons, the State sought guidance for future cases.

Table of Precedents Cited

Precedent	Rule or Principle Cited For	Application by the Court
Atchison Topeka and S.F.R. Co. v Matthews 174 US 96 (1899)	Quoted (via Tussman & tenBroek) for the proposition that while the equality guarantee exists, “laws may classify”, and “the very idea of classification is that of inequality”.	Used to illustrate that constitutional equality must tolerate some legislative classifications, focusing scrutiny only on those that are arbitrary, capricious or irrational.
Quinn’s Supermarket v Attorney General [1972] IR 1	Example of earlier jurisprudence interpreting “as human persons” in Article 40.1 narrowly, excluding trading and similar activities from equality protection.	Cited to show that Article 40.1 had a limited practical impact for many years, with successful challenges often being grounded instead on Article 40.3 unenumerated rights.
Murtagh Properties v Cleary [1972] IR 330	Further authority for the earlier, restrictive reading of Article 40.1, limiting its scope to equality “as human persons” and excluding commercial activity.	Referred to as part of the historical background explaining why Article 40.1 was under‑developed until more recent case law.
Murphy v Ireland [2014] IESC 19; [2014] 1 IR 198	Part of a line of modern authorities advancing the development of Article 40.1 jurisprudence.	Cited as one of several decisions culminating in a more systematic restatement of equality principles in Donnelly v Minister for Social Protection.
NHV v Minister for Justice and Equality [2017] IESC 35; [2018] 1 IR 246	Another key step in the modern development of equality and related rights under the Constitution.	Referenced as part of the background leading to the comprehensive analysis of Article 40.1 in Donnelly.
Donnelly v Minister for Social Protection & Ors [2022] IESC 31; [2023] 2 IR 415	Sets out core principles for Article 40.1: Protection against discrimination based on arbitrary, capricious or irrational considerations; Burden of proof on the challenger and presumption of constitutionality; Deference to the Oireachtas in social, fiscal and moral policy; Closer scrutiny for classifications touching intrinsic aspects of human personality or vulnerable groups; Rejection of a proportionality test for Article 40.1.	Adopted as the primary template for analysis. The Court applies its rationality standard, its emphasis on separation of powers, and its warning against treating equality review as either “strict in theory, fatal in fact” or effectively toothless.
Cahill v Sutton [1980] IR 269	Remark (by a member of the Supreme Court) that oral evidence gives “force and life” to a case in a way affidavits cannot.	Used to underline the Court’s view that plenary proceedings with oral evidence are generally preferable for fact‑sensitive constitutional challenges, and that the absence of such evidence hindered full exploration of the present claim.
O’Meara v Minister for Social Protection & Ors [2024] IESC 1; [2024] 1 ILRM 437	Authority on discrimination based on marital/family status. Also contains a statement that marital status is different from immutable characteristics such as gender, race, ethnicity or age, and is not necessarily the subject of prejudice or stereotyping.	Relied on by the Appellants to support an argument that the Minor Appellant suffers discrimination on the basis of parental marital status. Relied on by the Court to emphasise that marital status is not an immutable personal characteristic in the same way as age or race and therefore does not automatically attract heightened scrutiny.
Mallon v Minister for Justice [2024] IESC 20	Observation that there is no indication in the Supreme Court’s Article 40.1 jurisprudence that age is to be treated as a “suspect” ground.	Used to support the Court’s refusal to classify age, and in particular the minority/adulthood distinction, as a suspect ground requiring strict scrutiny, reinforcing the rationality standard.
Sinnott v Minister for Education [2001] IESC 63; [2001] 2 IR 545	Held that the State’s obligation under Article 42.4 to provide for education is limited to individuals under the age of 18.	Cited to demonstrate that age‑based distinctions, including between minors and adults, are recognised and accepted in the Constitution itself.
Fleming v Ireland [2013] IESC 19; [2013] 2 IR 417	States that laws classifying by race, religion, gender or nationality attract close scrutiny, while classifications by age or disability may be “suspect or may be easily explained”, with benefits by age often easy to justify.	Used to show that age may sometimes be a ground of concern, but is not on the same footing as race or gender and can often be justified, supporting the Court’s choice of a rationality rather than strict‑scrutiny test.
Re Article 26 and the Employment Equality Bill 1996 [1997] IESC 6; [1997] 2 IR 321	Held that legislative classifications based on age “could not plausibly be characterised as irrational or arbitrary” and fall into a different constitutional category from distinctions on grounds such as sex or race.	Cited, together with modern anti‑discrimination statutes, to reinforce that age‑based distinctions, particularly around minority/adulthood, are not inherently suspect for constitutional purposes.
JD v Residential Institutions Redress Committee [2009] IESC 59; [2010] 2 ILRM 181	Explained in later High Court jurisprudence as acknowledging that age‑based classifications are not, in themselves, invidious or discriminatory, but may be so if arbitrary, irrational or unfair.	Quoted via Brophy v DPP Ireland and the Attorney General and endorsed by the Court to support the proposition that age discrimination can be constitutionally objectionable where irrational, but age as such is a regularly and legitimately used classification.
Brophy v DPP Ireland and the Attorney General [2024] IEHC 392	High Court decision summarising JD as recognising that age‑based classifications are not automatically discriminatory but may be held so if arbitrary or unfair.	Approved by the Supreme Court as correctly reflecting the constitutional approach to age discrimination under Article 40.1.
In the matter of B (a minor); Child and Family Agency and B v Adoption Authority of Ireland and C and Z [2023] IESC 12	Explains the background and objective of Article 42A as recalibrating the constitutional balance between family rights and the rights of children, particularly in the context of care, custody and adoption.	Cited to support the view that Article 42A.1 is primarily concerned with ensuring that children’s rights are not subordinated to parental rights in family‑law contexts, rather than mandating particular outcomes in areas such as landlord‑and‑tenant law.
JB v KB [2018] IESC 30; [2019] 1 IR 270	Earlier Supreme Court judgment discussing the implications of children’s rights in family disputes.	Referenced (via B (a minor)) as part of the explanation of Article 42A’s purpose and context; not directly applied to the facts but used to situate Article 42A within the broader family‑law framework.
AZ and Ors v Minister for Justice and Equality [2024] IESC 35	Held that Article 42A.1 requires the Minister, in deportation decisions affecting a child (particularly a child with special needs whose primary carer would be deported), to have regard to the child’s natural and imprescriptible rights; the child’s best interests are a primary consideration.	Used to illustrate that Article 42A.1 has real effect in administrative decisions directly affecting a child’s care and family life, but distinguished as not supporting the contention that the Oireachtas must structure tenancy‑succession legislation around a generalised “best interests” test.
Meath County Council v Murray [2017] IESC 25; [2018] 1 IR 189	Leading authority on Article 40.5, holding that: Article 40.5 is not confined to preventing forcible entry only; any entry other than one “in accordance with law” is prohibited; and The Article should not be transformed into an unqualified, free‑standing guarantee with unlimited reach.	Relied on as the most authoritative statement on Article 40.5. The Court applied its cautious approach, resisting an expansive reading of “inviolability” that would unsettle landlord‑and‑tenant law and emphasising that lawful recovery of possession following termination of a tenancy is “in accordance with law”.
Clare County Council v McDonagh [2022] IESC 2; [2022] 2 IR 122	Recognised that Article 40.5 may be a relevant factor in applications for interlocutory relief where a public authority seeks to recover property from members of a marginalised and socially vulnerable group to whom it owes housing obligations, while affirming Murray as the governing approach.	Cited to confirm that Article 40.5 can influence equitable remedies in certain circumstances but does not support using Article 40.5 to invalidate s.39(3) or to create a general prohibition on recovery of any dwelling by its lawful owner.
Sullivan v Boylan [2012] IEHC 389	High Court dicta advocating a broad reading of Article 40.5 centred on the concept of “inviolability”.	Referred to as part of a line of decisions suggesting an expansive approach to Article 40.5, but the Supreme Court reiterated that this broader view has not been adopted at Supreme Court level, preferring the more limited approach in Murray.
Irish Life and Permanent plc v Duff [2013] IEHC 43; [2013] 4 IR 96	Another High Court decision favouring a more expansive interpretation of Article 40.5.	Grouped with other first‑instance cases as reflecting an approach to Article 40.5 which the Supreme Court has not endorsed.
Wicklow County Council v Fortune (No. 1) [2012] IEHC 406	High Court decision in which Article 40.5 was considered in the context of a local authority’s attempt to recover land.	Cited, with Fortune (No.2), as part of the background to the debate about an expansive reading of Article 40.5; contrasted with the Supreme Court’s more restrained approach.
Wicklow County Council v Fortune (No.2) [2013] IEHC 255	Further High Court elaboration on the potential scope of Article 40.5.	Again mentioned as part of a series of cases proposing a broader conception of “inviolability”, which the Supreme Court declined to adopt.
King v Attorney General [1981] IR 233	States that legislation is unconstitutional if it “stoops to methods which ignore the fundamental norms of the legal order postulated by the Constitution”.	Used as the benchmark for judging whether a law authorising entry onto a dwelling (or related regulation) offends Article 40.5; the Court held that s.39(3) does not fall into that category.
Murphy v The Attorney General [1982] IR 241	Establishes that where a statutory provision is declared repugnant to the Constitution, it is normally invalid ab initio and cannot provide legal justification for acts done under it.	Invoked in the discussion of “underinclusive” legislation to emphasise that a finding of unconstitutionality usually results in the relevant provision being invalidated, rather than left in force pending legislative amendment.
Heneghan v Minister for Housing (No. 2) [2023] IESC 18; [2023] 2 ILRM 97	An exceptional case where the Court, in the context of Seanad electoral legislation forming part of the constitutional architecture, effectively compelled legislative amendment and could not simply strike down the statute without paralysing the system.	Distinguished as a unique situation and not a template for equality‑based challenges such as the present case. The Court cautioned against turning such exceptional measures into routine tools for directing the Oireachtas.
Re SC [2021] UKSC 26; [2022] AC 223	United Kingdom Supreme Court authority (per Lord Reed) warning that broad application of equality guarantees (Article 14 ECHR) to all legislative distinctions risks undue interference with the democratic sphere of political choice.	Used by analogy to support a restrained approach to Article 40.1, reinforcing that once a classification is not arbitrary, capricious or based on prejudice, courts should not overreach by substituting their own policy views for those of the legislature.
Railway Express v New York 336 US 106 (1949)	States that equality guarantees are most effectively enforced by insisting that principles applied to a minority be applied generally; a core statement about underinclusive classifications.	Quoted to explain why underinclusive legislation can pose a central equality problem and why, if a statute’s underinclusivity is unconstitutional, the usual outcome is to invalidate the provision.
United States v Butler (1936) 297 US 1	Cited for Chief Justice Stone’s observation that “courts are not the only agency of government that must be assumed to have capacity to govern”.	Used to emphasise separation of powers and to caution against courts unduly intruding into the policy‑making role of the legislature, particularly in complex social and economic fields such as housing regulation.

Court's Reasoning and Analysis

The Court’s analysis proceeded in several stages: procedural form, the marital‑status argument, the age‑discrimination argument, the impact of Articles 42A and 40.5, and the doctrine of underinclusive legislation.

1. Procedural Form: Judicial Review vs Plenary Proceedings

The Court noted that the case had evolved from a judicial review challenging an administrative decision by Company A, with an ancillary constitutional point, into a pure, direct challenge to the validity of a provision of primary legislation entitled to a presumption of constitutionality. It endorsed the view previously expressed that proceedings directly contesting the validity of such legislation “will often be more appropriately dealt with in plenary form”.

The Court held that, going forward, challenges consisting of a direct attack on the validity of primary legislation should, as a matter of principle, be brought by way of plenary proceedings. This allows:

• Oral evidence to be given and tested;
• Discovery and interrogatories where necessary;
• Richer exploration of factual context, especially in cases said to demonstrate undue hardship.

However, the Court declined to dismiss the present appeal on procedural grounds, recognising the understandable urgency at commencement, the original inclusion of administrative‑law claims, and the fact that both the High Court and Supreme Court had already engaged with the core constitutional issue.

The Court observed that the evidence filed had been directed largely to the interaction with Company A rather than to the constitutional issue itself, and that the lack of oral evidence meant that the equality case rested on a bare factual core. Given the presumption of constitutionality and the onus on the challenger, this evidential shortfall weighed against the Appellants’ case.

2. Alleged Discrimination Based on Parental Marital or Family Status

The Court rejected the Appellants’ contention that s.39(3)(a) discriminates on the basis of parental marital status or family structure. Although the Minor Appellant cannot remain in the premises while a hypothetical child of a two‑parent family might, that difference in outcome also arises where any other qualifying adult occupier exists at the time of death (for example, a non‑parent cohabitant, a parent of the deceased tenant, or an adult sibling).

The decisive factor is whether there is an adult within the limited statutory class who was living in the dwelling at the time of death and elects to succeed, not whether the child’s parents were married, separated, or cohabiting. All children under 18 are, as a matter of law, treated alike: none can themselves succeed to the tenancy; their ability to remain is contingent on the decision and status of adults.

The Court further observed that granting the First Appellant a right to succeed would require a substantial departure from the coherent structure of s.39(3)(a), which:

• Limits succession to certain close adult relatives; and
• Requires that they were residing in the premises at the date of death.

Allowing a non‑resident sibling (or other relative) to succeed would create fresh lines of differentiation, undermining the scheme’s internal logic. In the specific context of an approved housing body, it would also allow a person who has not been assessed as having a housing need to acquire a long‑term social tenancy, potentially displacing those on housing lists.

3. Age‑Based Distinction and Article 40.1

(a) Is Age a “Suspect” Classification?

The Court accepted that s.39(3)(a) draws a clear line on the basis of age: child relatives aged 18 or over may succeed; those under 18 may not. The Court therefore turned to whether age—or specifically the distinction between minority and adulthood—should be treated as comparable to race or gender in attracting close or strict scrutiny.

Having regard to its own jurisprudence and the broader constitutional and legislative framework, the Court concluded that age is not a suspect ground in the same sense as race or gender, particularly when the issue is the widely recognised legal threshold between minority and adulthood. The key reasons were:

• Age is an immutable characteristic in one sense, but it changes over time and is not typically associated with enduring prejudice or stereotyping in the same way as race, ethnicity or sex.
• The Constitution expressly permits age‑based distinctions in several provisions (for example, in voting rights and eligibility for political office, and in limiting the education guarantee to under‑18s).
• Equality legislation recognises age as a discriminatory ground but specifically limits or qualifies its operation for minors, reflecting that treating under‑18s differently is often legitimate.
• Past Supreme Court and High Court decisions have emphasised that age‑based classifications are not inherently invidious, although they may be struck down if arbitrary or irrational.

The Court endorsed the approach in Donnelly, which resists rigid taxonomies of “suspect” classifications and instead assesses whether a particular statutory distinction is arbitrary, capricious or irrational and whether it reflects prejudice or unjustified stereotypes. It declined to adopt the stricter approach proposed in another judgment, which would have treated children’s vulnerability as a basis for subjecting all minority/adulthood distinctions to heightened scrutiny.

(b) Rationality of the Distinction in Section 39(3)(a)

Applying the rationality test derived from Donnelly, the Court asked whether the age‑based limitation in s.39(3)(a) is arbitrary, capricious or otherwise not reasonably capable, in light of the social function involved, of supporting the legislative objective.

The Court emphasised that:

• The underlying objective of Part 4 is to provide a strong measure of security for tenants while balancing landlords’ property rights. Initially, Part 4 tenancies ran for four years; they have since been extended to six years and now to unlimited duration.
• Section 39(1) confirms that even these enhanced statutory tenancies terminate on the tenant’s death, reflecting the traditional common‑law rule. Section 39(3) creates a further, exceptional privilege for a narrow class of close adult relatives who were living in the premises at the date of death to succeed to the tenancy.
• From the landlord’s perspective—whether a private landlord or an approved housing body—the succession provision represents a further limitation on property rights and on the normal incidents of ownership. The breadth and limits of that entitlement are matters of social and economic policy entrusted to the Oireachtas.
• Requiring landlords to accept minor children as tenants as of right—potentially from infancy upwards—would be a qualitatively different intervention. While the common law permits landlords, if they so choose, to enter into contracts with minors (with voidability protections), a statute that compels all landlords to accept minor successors would be an entirely different proposition.

The Court also highlighted the wide range of situations to which s.39(3) applies: private landlords and approved housing bodies, children of very different ages and capacities, and differing family configurations. Against that background, a bright‑line rule restricting statutory succession to adults is a common and rational legislative tool, even if it leads to marginal hard cases.

In response to Company B’s reliance on contract‑law authorities about minors, the Court noted that those rules themselves reinforce that minors are treated differently from adults and that they concern voluntary agreements, not compulsory statutory obligations imposed on landlords.

The Court further observed that neither the Appellants nor Company B had articulated a coherent and constitutionally secure alternative line. Options such as:

• Allowing non‑resident relatives to succeed; or
• Making minors statutory tenants as of right;

would raise new and difficult issues of fairness, administrative feasibility, and consistency with housing‑need criteria, particularly for approved housing bodies. This difficulty in identifying a viable alternative was seen as reinforcing that the existing classification is rational rather than arbitrary.

4. Article 42A (Rights of the Child)

The Court accepted that Article 42A affirms that children possess “natural and imprescriptible rights” and imposes a duty on the State, so far as practicable, to protect and vindicate those rights. However, it characterised Article 42A.1 as largely declaratory, intended principally to rebalance the constitutional position between the family (often equated in practice with parents) and the child in family‑law contexts.

The Court noted that the specific provisions of Article 42A.2 to 42A.4—which embed a “best interests of the child” standard and a requirement to ascertain and consider the child’s views—apply in defined contexts such as safety, welfare, adoption, guardianship, custody and access. Those provisions were not engaged by the present case, which does not concern State intervention in the family or child‑protection proceedings.

Turning to Article 42A.1, the Court held:

• There is no textual or historical basis for treating it as an open‑ended mandate for courts to substitute their own views as to what is best for children in all social‑policy fields, including landlord‑and‑tenant law, for the considered judgment of the Oireachtas.
• It has not previously been suggested that there exists a natural and imprescriptible right of a child (or adult) to live in a particular dwelling contrary to the wishes of the property owner.
• There was no evidence that the operation of s.39(3) would leave the Minor Appellant without any home or without a responsible adult to care for him.
• The law of minors’ capacity, which underpins the age‑based limitation in s.39(3), is itself historically child‑protective, guarding minors against onerous obligations while allowing necessary contracts for “necessaries”.

The Court concluded that Article 42A does not require landlords to accept minor children as statutory tenants in succession to a deceased tenant, nor does it render s.39(3)(a) unconstitutional when read together with Article 40.1.

5. Article 40.5 (Inviolability of the Dwelling)

The Court reviewed recent case law on Article 40.5 and reaffirmed the approach adopted in Meath County Council v Murray. It accepted that Article 40.5 is not confined strictly to barring forcible entry; any entry not “in accordance with law” is prohibited. However, the Court rejected the suggestion that Article 40.5 creates a broad, free‑standing, horizontally applicable guarantee which would allow courts to veto legislative choices about when landlords may lawfully recover possession of property.

Applying that framework, the Court found that:

• Section 39(3) does not itself authorise entry onto or eviction from a dwelling. Rather, it defines when an otherwise ongoing Part 4 tenancy continues or ceases upon death; s.39(1) provides that, subject to specified exceptions, the tenancy terminates on death.
• Any subsequent re‑entry by a landlord entitled to possession is an exercise of property rights “in accordance with law”, namely, the general law of landlord and tenant as concretised by s.39(1).
• Part 4, far from representing an invasion of dwelling rights, constitutes a substantial restriction on landlords’ rights in favour of tenants and their adult relatives.

The Court rejected a more expansive reading, advanced in a separate judgment, which drew on continental constitutional history and interpreted “inviolable” as severely limiting the State’s or landlords’ ability to terminate occupation. The Court noted that:

• That interpretative approach had not been argued by the parties;
• There was no evidence that the foreign constitutional models relied upon had ever been interpreted in that fashion; and
• Even on a strong reading of “inviolable”, Article 40.5 explicitly permits entry “in accordance with law”, leaving the critical question whether the law itself is consistent with the “fundamental norms of the legal order”.

The Court held that there is nothing contrary to those norms in providing that a tenancy terminates on the tenant’s death or in allowing the landlord then to recover possession, particularly where the Oireachtas has chosen to go further by creating statutory succession rights for certain adult co‑occupants. To hold otherwise would imply that landlord‑and‑tenant law had been constitutionally defective for decades and would render the Court the ultimate arbiter of virtually all aspects of the housing market.

6. Underinclusive Classifications and Remedies

The Court engaged in a detailed discussion of the concept of underinclusive classifications in equality law, drawing on academic analysis and prior case law.

It noted that:

• Equality guarantees do not create substantive entitlements; they instead require that benefits or burdens, once distributed, are not withheld from similarly situated persons on constitutionally impermissible grounds.
• A classification is “underinclusive” where the legislature addresses a legitimate objective but leaves out some individuals who are similarly placed in respect of that objective.
• Underinclusivity can, in some circumstances, be constitutionally less troubling than overinclusivity, especially where the legislature is proceeding incrementally or experimentally.

However, the Court stressed that if an underinclusive classification is ultimately held to be unconstitutional under Article 40.1, the ordinary consequence is invalidity from the date of enactment, as explained in Murphy v The Attorney General. Leaving such a provision formally in force while exhorting the Oireachtas to “fill the gap” is not generally consistent with constitutional principles and can generate serious separation‑of‑powers tensions.

The Court distinguished the exceptional situation in Heneghan v Minister for Housing (No. 2), where the impugned statute was part of the constitutional architecture governing Seanad elections and where striking it down would have prevented any valid legislation being enacted. It held that this case, concerning succession to tenancies, is far removed from that context.

In the present case, the repeated characterisation of s.39(3) as underinclusive did not, in the Court’s view, lower the threshold for invalidity. Because the Court found the age‑based line to be rationally connected to the statute’s purpose and not grounded in prejudice or arbitrary exclusion, Article 40.1 was not breached and the question of remedial options did not arise.

7. Cumulative Arguments and Practical Considerations

The Appellants and Company B suggested that, even if no single constitutional provision were determinative, Articles 40.1, 42A and 40.5, taken together, should lead to a finding of invalidity. The Court rejected this “synergistic” approach, holding that:

• If each provision, properly understood, is not infringed on its own terms, combining them does not create a new, free‑floating standard allowing courts to rewrite carefully calibrated legislation.
• Adopting such an approach would effectively transform Article 40.1 from a protection against prejudicial or irrational classifications into a general power to revise legislative policy wherever the courts perceive individual hardship.

The Court also reflected on the practical consequences of the litigation. The apartment, part of a scarce social‑housing stock, had remained largely unoccupied for more than three years while the proceedings were pending. Yet, even had the challenge succeeded, no immediate order could have granted the Minor Appellant a right to remain; further legislation would have been required, and the Oireachtas could have responded in ways providing no benefit to him.

The Court regarded this as illustrating the risks of broad constitutional challenges which may immobilise important social resources without a clear, legally attainable remedy for the individual litigant. It underscored the need for clarity and focus in framing constitutional claims.

Holding and Implications

Holding: The Supreme Court held that section 39(3)(a) of the Residential Tenancies Act 2004 (as amended), which permits succession to a Part 4 tenancy only by certain adult co‑occupiers (including adult children) and not by minor children, is not repugnant to the Constitution. The Court rejected:

• The claim of indirect discrimination based on parental marital status or family structure;
• The claim of unconstitutional age discrimination, holding that the minority/adulthood distinction is subject to a rationality standard and is rationally related to the statute’s objectives;
• The contention that Article 42A requires legislative provision for minor succession to tenancies in these circumstances; and
• The argument that Article 40.5 invalidates s.39(3) or constrains the landlord’s right, “in accordance with law”, to recover possession upon termination.

The Court therefore dismissed the appeal and upheld the constitutionality of s.39(3)(a). No relief was granted to the Appellants against the Respondent State, and no relief was sought against Company A by the time of the appeal.

Implications:

• The decision confirms that age‑based distinctions, particularly the line between minority and adulthood, are not “suspect” classifications under Article 40.1 and will be assessed on a rationality standard, though they can still be struck down if arbitrary, capricious or grounded in prejudice.
• It reinforces the approach in Donnelly: equality review must respect the presumption of constitutionality, the separation of powers, and the legislature’s role in calibrating complex social and economic policies such as housing regulation. Courts may not expand statutory schemes simply because a more inclusive policy would seem “fairer” in an individual case.
• The judgment clarifies that Article 42A.1 does not constitute a general mandate to reshape social‑policy legislation around a broad “best interests of the child” test, particularly where the legislation does not directly concern care, custody or State intervention in the family.
• It re‑affirms a measured, context‑sensitive interpretation of Article 40.5, under which lawful recovery of possession after termination of a tenancy is “in accordance with law” and not per se unconstitutional, and under which Article 40.5 does not serve as a basis for invalidating the statutory framework for residential tenancies.
• On procedure, the Court gives clear guidance that direct challenges to the validity of primary legislation should ordinarily be initiated by plenary proceedings, not judicial review, so that the factual matrix can be explored in sufficient depth. Where a constitutional claim arises incidentally in judicial review against an administrative act, courts may nonetheless direct that it proceed in plenary form if the constitutional issue is substantial.
• The ruling does not create new substantive entitlements to housing or to succession to tenancies. Its practical effect is to leave in place the existing legislative scheme under which minor children cannot themselves succeed to a Part 4 tenancy on a tenant’s death, and where any continuation of their occupation is contingent on a qualifying adult occupier’s succession or other housing arrangements. The Court’s reasoning emphasises that any reform of this position is a matter for the Oireachtas, not for judicial re‑design via Article 40.1.