Professional Negligence and the Duty of Care: Lessons from the High Court

The High Court, in Ashdrum Lodge Ltd t/a Kiernan Homes v Barbouti & ors [2025] IEHC 522, has provided important clarification on the duty of care owed by architects to their clients, the extent to which a client’s conduct can affect an architect’s ability to discharge those duties, and the role of contributory negligence under the Civil Liability Act 1961 in assessing an architect’s liability.

Background

The owner of Derrybawn House in County Wicklow engaged a contractor and a supervising architect in respect of refurbishment works (the Works) at the property.  Instead of entering a formal bespoke contract, the parties operated under the Standard Blue Form RIAI Contract (2012 edition) and the Standard RIAI Agreement between Client and Architect for the Provision of Architect’s Services (2007 edition) (RIAI Architect Contract) respectively.

The Works began in 2013 with an initial estimate of €360,000. However, due to ongoing instructions, the final cost exceeded €5 million. During the course of the engagement, relations between the parties deteriorated and the property owner dismissed the contractor and architect prior to the completion of the Works.

Legal Proceedings

These proceedings were initiated by the contractor against the property owner for unpaid sums. The property owner counterclaimed alleging defects in the contractor’s workmanship. These two claims were settled relatively early in the trial. However, in the interim, the architect had been joined to the proceedings as a third party.

The architect conceded liability in respect of a number of items. However, the central issue in the third party action was whether the architect ought to have identified defects in the bedding mortar during visual inspections of the Works.

Judgement

Ms Justice Stack of the High Court held that an architect’s duty of care to their clients is determined by the scope and terms of their retainer. As such, the issues in dispute fell to be determined by reference to the Standard Services set out in the RIAI Architect Contract.

The Court noted that the architect’s duty, as outlined in the RIAI Architect Contract, was to conduct periodic visual inspections and, where a defect was identified, to intervene and direct that remedial action be taken. The Court emphasised that this duty did not extend to continuous supervision of the Works, nor did it amount to a guarantee of workmanship. The High Court was satisfied that the architect’s duty was as summarised in the English case of McGlinn v. Waltham Contractors Ltd. (No. 3) [2007] EWHC 149, which sets out inter alia that the frequency and duration of inspections should be tailored to the nature of the works going on at the site from time to time and that the architect does not guarantee that their inspection will reveal or prevent all defective work. Therefore, the mere fact the bedding mortar was defective did not establish liability on the part of the architect and the High Court found that the defects were not ascertainable during periodic visual inspection.

The Court found that the architect’s liability was limited to the other items, which had previously been accepted by him, and did not extend to the defective bedding mortar. As such, the balance of the claim was dismissed.

Importantly, the Court concluded that the property owner’s conduct in dismissing the contractor and excluding its workmen from the property prior to completion of the Works, dismissing the architect in response to his attempts to administer the terms of the building contract and preventing the architect from inspecting the Works which were still ongoing, was unreasonable. The Court held the property owner was, therefore, the author of her own misfortune and guilty of want of care and contributory negligence within the meaning of the Civil Liability Act 1961.

Conclusion

The judgment confirms that an architect’s duty does not implicitly include a guarantee of workmanship nor continuous supervision. Instead, it is defined by the retainer. Liability in this case depended on the ability of the plaintiff to demonstrate negligence in the form of a failure to conduct reasonable inspections and a failure to see what ought to have been reasonably apparent on the conducting of those visual inspections.

The judgment also illustrates the fundamental importance of having formal, defined contractual terms in place so that all parties clearly understand their respective duties, obligations and entitlements arising throughout a construction project.