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

Factual and Procedural Background

The second appellant (the “Minor Appellant”) is approximately seventeen years of age. He had been living with his mother as a one-parent family in an apartment held under a “Part 4” tenancy created by the Residential Tenancies Act 2004 (“the 2004 Act”). The tenancy was held from the notice party, a social housing provider (“Company A”).

The tenancy continued until it lapsed on the death of the Minor Appellant’s mother in July 2023, when she was murdered. An individual has been convicted of that murder in a foreign court. The first appellant (the “First Appellant”) is the Minor Appellant’s maternal aunt and has been appointed his legal guardian.

Because the Minor Appellant was under eighteen, he did not fall within the list of eligible persons in section 39(3) of the 2004 Act who may elect, under section 39(2), to become the tenant of a Part 4 tenancy in place of a deceased tenant. Around 2023, Company A sought to terminate the tenancy. Since his mother’s death, the Minor Appellant has lived with his maternal grandparents, though he has been allowed access to visit his former home. Company A has not, in these exceptional circumstances, re-let the apartment to another family.

The appellants challenge the constitutionality of the legislative scheme on the basis of “unconstitutionality by omission”. They do not contend (for the purpose of this appeal) that section 39(3) of the 2004 Act is itself invalid in the sense that it should be struck down. Rather, they argue that by failing to cater for the special situation of a minor occupier in the position of the Minor Appellant, the legislature has breached his constitutional rights by omission, leaving an unconstitutional gap in the 2004 Act. In particular, they complain that there is no legal mechanism under which, at least in some circumstances, a tenancy would not automatically terminate on the death of the tenant where the other occupier is a minor, for example by allowing a legal guardian to take over the lease.

The appellants relied on several constitutional provisions, including equality (Article 40.1), property rights (Article 40.3.2°), the inviolability of the dwelling (Article 40.5), and children’s rights (Article 42A). This judgment focuses on Article 40.5 and Article 42A, while noting agreement in general with another judgment of the Court on the equality issue.

Procedurally, the case was brought by way of judicial review, although the real objective was to secure a finding that the legislation is unconstitutional by omission, rather than to quash any particular administrative decision. The judgment discusses whether such constitutional challenges should instead be commenced by plenary summons but ultimately proceeds to determine the merits because the relevant facts are not in dispute.

Legal Issues Presented

1. Whether constitutional challenges of this kind should ordinarily be brought by plenary summons rather than by way of judicial review, and whether the use of judicial review in this case precluded the Court from deciding the constitutional issues.
2. How Article 40.5 of the Constitution, which guarantees the inviolability of the dwelling, should be interpreted: specifically, whether it is confined to the criminal or quasi-criminal sphere (as an analogue of the Fourth Amendment to the United States Constitution) or whether it also has substantive implications for civil law relationships such as landlord and tenant.
3. Whether the automatic termination of a Part 4 tenancy on the death of the tenant, without any possibility of continuation where the remaining occupier is a minor, is compatible with the guarantee of the inviolability of the dwelling in Article 40.5.
4. Whether, read together with the general guarantee of children’s rights in Article 42A.1, the failure of the legislature to provide any mechanism for a minor child to remain in the family home (for example through a guardian taking over the lease) constitutes an unconstitutional legislative omission.
5. Whether the Court may, consistently with the separation of powers, declare such an omission unconstitutional and what the nature and urgency of the legislature’s remedial obligation should be.

Arguments of the Parties

The opinion does not contain a detailed account of the parties' legal arguments.

Table of Precedents Cited

Precedent	Rule or Principle Cited For	Application by the Court
[1999] 4 IR 343	Constitutional challenges are generally better brought by plenary summons rather than judicial review, but no rigid rule governs the form of proceedings.	Used to support the view that, although judicial review was used here, plenary proceedings are usually preferable for constitutional litigation; however, the Court proceeded because the facts were not in dispute.
[2025] IESC 35	Fact-finding is generally essential in constitutional cases, and the plenary summons procedure is usually best suited to receiving and testing evidence.	Relied on to emphasise that constitutional adjudication should rest on clear factual findings, reinforcing the preference for plenary procedures in future cases.
[1965] IR 142	Early interpretation of Article 40.5 confirming that the constitutional protection of the dwelling is not limited to forcible entry but reflects a broader guarantee.	Cited to show that Article 40.5 contains a substantive guarantee of inviolability in addition to the specific reference to forcible entry “in accordance with law”.
[2022] IESC 2; [2022] 2 IR 122	Historical and comparative analysis indicating that the “inviolability” of the dwelling in Irish constitutional law was influenced by continental European constitutions, particularly the Weimar Constitution.	Used to support the view that “inviolability” is a concept drawn from a civilian constitutional tradition in which the home has an elevated status.
[1950] IR 67	The Constitution should, so far as possible, be construed in a way that gives constitutional objectives “life and reality”.	Invoked to justify giving meaningful content to the word “inviolable” in Article 40.5, rather than treating it as empty or merely rhetorical.
[2012] IEHC 385	Analysis of the Irish-language text of Article 40.5, emphasising that it conveys ideas of safety and security of the dwelling.	Cited to reinforce that the Irish text supports understanding “inviolability” as guaranteeing a safe, secure dwelling for the citizen.
[2012] IECCA 68	Description of the dwelling as a protected place of repose and privacy, with Article 40.5 complementing other constitutional rights such as dignity, protection of the person, family life, and children’s rights.	Used to articulate that Article 40.5 aims to ensure a secure, private zone where the dignity and security of residents are protected against all intrusions except in exceptional, legally justified circumstances.
[2023] IESC 7; [2023] 3 IR 419	The Constitution must be read holistically; no single provision can be considered in isolation from others, including property-rights guarantees.	Applied to emphasise that Article 40.5 must be balanced against the landlord’s property rights protected under Article 40.3.2°, and that legislation such as the 2004 Act is an effort to respect those rights.
[1982] IR 117	The State must protect and vindicate property rights and ensure a fair balance between the rights of landlords and tenants.	Relied on to support the proposition that landlord property rights must be respected, but balanced against tenants’ and occupiers’ constitutional protections, including inviolability of the dwelling.
[2024] IESC 35	Clarification of Article 42A: Article 42A.1 provides a general guarantee of children’s rights applying to all aspects of a child’s life, whereas Article 42A.4 concerns specific proceedings where the best interests of the child are the paramount consideration.	Used to classify the present case as one governed by Article 42A.1 (general duty to protect children’s rights with regard to their best interests), not Article 42A.4 (where best interests are paramount).
[1977] IR 55	Recognition that the best interests of the child must be balanced against other legitimate considerations, such as property rights, except where the Constitution makes them paramount.	Cited to acknowledge that, in landlord and tenant legislation, the legislature may balance children’s interests with other interests, provided constitutional obligations are respected.
[1982] IR 384	Reference to the historical experience and “race-memory” that influenced the drafting of the Constitution.	Invoked to suggest that historical experience of forced evictions and land struggles likely contributed to the decision to confer a special constitutional status on the home.
[2013] IEHC 43; [2013] 4 IR 96	Identification of elements inherent in the inviolability of the dwelling: formal notice, foreseeability, and an independent determination of the necessity for recovering possession, ordinarily within or akin to a judicial process.	Used to critique the 2004 Act’s treatment of tenancies that terminate automatically on a tenant’s death, noting the absence of those safeguards where a minor remains in occupation.
[2023] IESC 18; [2023] 3 IR 419	Once a constitutional breach is identified, the branch of State responsible has a duty to remedy it as soon as feasible; failure to take steps to do so can itself constitute a breach of constitutional duty.	Relied on to assert that the current legislature bears an immediate constitutional obligation to cure the identified omission and that the Court’s decision is not merely advisory.
[2024] IESCDET 109	Determination granting leave to appeal, which required the appellants to clarify whether and to what extent they relied on Article 40.5.	Referenced to explain why the Article 40.5 issue, though lightly pressed in the High Court, was squarely before the Supreme Court on appeal.

Court's Reasoning and Analysis

Form of Proceedings

The judgment first addresses whether proceedings aimed primarily at impugning the constitutionality of legislation should be brought by judicial review. It notes that applicants often use judicial review where their real goal is a finding of unconstitutionality, and states that this practice should generally not be endorsed. Prior authority and a recent decision are cited for the proposition that plenary summonses are usually preferable in constitutional litigation because they facilitate full fact-finding.

However, there is no rigid rule on form of proceedings, and the Constitution itself envisages that statutes may be declared invalid in the course of various types of applications. Given that the salient facts here are not disputed, the Court proceeds to assess the constitutional complaint notwithstanding the use of judicial review.

Scope and Meaning of Article 40.5 (“Inviolability of the Dwelling”)

The judgment then turns to Article 40.5. It poses the central question: is Article 40.5 confined to protecting against unreasonable searches, akin to the Fourth Amendment to the United States Constitution, or does the guarantee of “inviolability” confer a broader, elevated protection in the civil sphere, including landlord–tenant relations?

Textually, the provision is said to contain two elements: (a) a statement that the dwelling of every citizen is “inviolable”; and (b) a proviso that forcible entry may occur “in accordance with law”. If the intention were solely to limit searches and seizures, the stronger word “inviolable” would have been unnecessary and could have been replaced by a more limited guarantee against forcible entry. The presence of “inviolable” therefore requires that real weight be accorded to this concept.

The judgment undertakes a historical and comparative analysis. It notes that Article 40.5 closely tracks Article 7 of the 1922 Constitution, which in turn took language from continental constitutions, especially the Weimar Constitution, where the dwelling was described as a “sanctuary” and “inviolable”. Similar language appears in other European constitutional texts, and “inviolability” has no precise antecedent in the common law tradition. The Irish-language version of Article 40.5 is also examined and is said to emphasise safety and security of the home.

From prior case law and commentary, the judgment distils that Article 40.5 secures a “safe, secure, and private zone” in which the dignity of the person is protected, and that the dwelling is set apart as a place of repose and privacy. This protection reinforces other constitutional values, such as dignity, bodily integrity, family life, and children’s rights.

At the same time, Article 40.5 cannot be read in isolation. The landlord’s reversionary interest and contractual rights under the tenancy are also protected as property rights under Article 40.3.2°. Legislation like the 2004 Act represents an attempt by the legislature to balance those rights with tenant protections, for example by allowing termination in cases such as non-payment of rent or serious anti-social behaviour. In such cases, the guarantee of inviolability does not prevent a landlord from recovering possession in accordance with law.

Application of Article 40.5 to the Present Facts

The present case is distinguished from normal termination grounds. There is no suggestion that, but for the death of the Minor Appellant’s mother, Company A could otherwise have terminated the tenancy during the remaining Part 4 period. The landlord’s entitlement to possession arises solely because of the mother’s sudden, unlawful death while the Minor Appellant was still a minor.

The judgment concludes that the assurance of security and protection inherent in “inviolability” would be fundamentally undermined if a landlord could recover peaceable possession simply because of such a fortuitous and tragic event, with no legal possibility for the tenancy to continue on behalf of the minor occupier. A regime under which a child loses the family home automatically upon a parent’s death, without the law providing any possibility for continuation of the tenancy, is said to compromise the essence of the inviolability guarantee.

The judgment also recalls prior authority that elements such as formal notice, foreseeability, and an independent assessment of the necessity for recovering possession are presupposed by inviolability. In the context of death of a tenant, the 2004 Act lacks these protections: the Part 4 tenancy ends automatically, there is no requirement for formal notice of termination, and the outcome is not subject to any form of judicial or quasi-judicial scrutiny triggered by the death itself. This contrasts with other termination scenarios under the Act where notice and procedure are prescribed.

Interaction with Article 42A (Children’s Rights)

The judgment then considers Article 42A.1, which recognises and affirms the natural and imprescriptible rights of all children and obliges the State, as far as practicable, to protect and vindicate those rights by its laws. Relying on a recent decision, it explains that Article 42A.1 is a general guarantee applying to all aspects of a child’s life, while Article 42A.4 applies to particular proceedings concerning child safety, adoption, guardianship, custody, and access, where the best interests of the child are the paramount consideration.

The present case falls within Article 42A.1, not Article 42A.4. In areas such as landlord and tenant law, the legislature must have regard to the best interests of the child, but may also weigh other legitimate considerations, such as the property rights of landlords. Nonetheless, the Court is struck by the complete absence of any statutory mechanism for protecting the interests of a child who, as here, is effectively rendered an orphan and risks losing the family home in addition to the loss of a parent.

While the law traditionally restricts minors from owning or contracting for immovable property, the judgment sees no reason why the legislature could not have provided some mechanism—perhaps involving a relative or legal guardian—by which a Part 4 tenancy might continue in appropriate circumstances after a tenant’s death, thereby giving effect to the State’s obligations under Article 42A.1.

An objection is considered that matters such as succession to tenancies are political questions within the legislature’s domain, and that it has already addressed succession in section 39 of the 2004 Act. The judgment acknowledges that the legislature has considered the issue generally, but emphasises that it has entirely failed to provide any mechanism at all addressing the specific situation of an orphaned minor occupier. The constitutional complaint is framed not as disagreement with the particular design of a legislative solution, but as a challenge to this total failure to legislate for a plainly foreseeable class of vulnerable children.

The judgment rejects the criticism that this interpretation of Article 42A would allow courts to invalidate legislation based on subjective views of what is best for children. It notes that the Constitution explicitly confers on the courts the power to review legislation for constitutionality and that Article 42A was adopted by the people relatively recently. It recognises that this is a significant and potentially fallible judicial power, which must be exercised with care, but stresses that it is a power and duty conferred by the Constitution itself.

Unconstitutional Omission and Legislative Duty

Drawing these strands together, the judgment concludes that, in a case involving a minor child and the family home, the guarantee of inviolability in Article 40.5, read with the general children’s rights provision in Article 42A.1, imposes a constitutional obligation on the legislature to provide some mechanism by which a minor under eighteen can seek to remain in the home, for example by a guardian taking over the lease after the parent–tenant’s death.

The absence of any such mechanism in the 2004 Act is characterised as a legislative omission that breaches these constitutional obligations. The judgment accepts that the Constitution does not offer solutions to all misfortunes but affirms that courts must protect enumerated fundamental rights when properly invoked.

Finally, the judgment invokes a recent authority which held that once a constitutional breach is identified, the branch of State responsible must remedy it as soon as feasible. The duty on the current legislature is described as immediate: it must not merely align the law with the Constitution at some unspecified time, but must take steps “now” to put a remedial legislative process in train. A demonstrable failure to do so would itself amount to a further breach of constitutional duty.

Holding and Implications

Holding: This judgment concludes that the legislature is in breach of its constitutional obligation to uphold and protect the inviolability of the dwelling under Article 40.5, when that guarantee is read in conjunction with Article 42A.1 in the case of a minor child, by failing to provide any statutory mechanism whereby a child under eighteen can seek to remain in the family home through a legal guardian taking over a Part 4 tenancy following the death of a parent–tenant. The judgment therefore states that the appeal should be allowed to that extent.

The judgment further indicates that, although the design of an appropriate legislative solution is primarily a matter for the legislature, the decision is not merely admonitory. It emphasises that the current legislature is under a constitutional duty to enact remedial legislation without undue delay. In line with a recent case, the Court proposes to invite submissions from the parties on whether a further order, requiring the legislature to legislate by a specified date, is necessary or appropriate.

Implications: The immediate consequence for the parties is the recognition that the statutory scheme governing Part 4 tenancies is unconstitutional by omission insofar as it fails to accommodate minor children in the position of the Minor Appellant. The judgment does not itself prescribe a specific legislative mechanism but requires that some avenue be created for a minor (through a guardian or similar representative) to continue in occupation of the family home after the tenant’s death, subject to appropriate balancing of landlord property rights.

More broadly, the judgment strengthens the substantive reach of Article 40.5 beyond search and seizure, confirming its relevance in civil contexts, and clarifies the interaction between the inviolability of the dwelling and the general children’s rights guarantee in Article 42A.1. It also underscores that constitutional breaches may take the form of legislative omissions and that, once such a breach is identified, the legislature bears an immediate and ongoing constitutional duty to remedy it. The opinion does not indicate that it sets out detailed new procedural rules, but it does signal that future constitutional challenges should usually proceed by plenary summons to permit full fact-finding.