Summary of Judgment

Factual and Procedural Background

This judgment, delivered by Judge O'Donnell on 30 January 2026, concerns contested costs applications arising from motions brought by the Eighth Defendant and the Ninth Defendant to amend their defences. The underlying proceedings were commenced by plenary summons on 20 August 2020; joinder of additional defendants occurred on 19 July 2021 and an amended plenary summons issued on 4 August 2021. A statement of claim was delivered on 12 November 2021. The claims relate to construction works carried out on a property known as The Property in The City between 2014 and 2016. The Plaintiffs are companies (purchasers by contract dated 8 February 2017) and the Defendants are companies said to have provided services or goods in connection with the works. The Plaintiffs claim defects discovered during further works in 2020; causes of action include breach of contract, negligence and breach of statutory duty. The Eighth Defendant was sued as architect and the Ninth Defendant as fire safety engineers.

The Eighth Defendant delivered a defence dated 2 August 2022 and the Ninth Defendant a defence dated 3 March 2022. Case management directions were made, discovery was exchanged by December 2023, and mediation followed. On 21 October 2025 the Plaintiffs delivered multiple witness statements and expert reports. The Eighth Defendant issued its motion to amend on 10 November 2025 (grounded on an affidavit sworn by Attorney Burke). The Ninth Defendant issued its motion on 12 November 2025 (grounded on an affidavit sworn by Attorney Conaty). The Plaintiffs opposed by affidavits sworn by Attorney Breen on 26 November 2025. Reply affidavits were sworn by Attorney O'Hara (for the Ninth Defendant) and Attorney Burke (for the Eighth Defendant). The Plaintiffs withdrew their opposition on the evening of 16 December 2025 shortly before a hearing listed for 18 December 2025. The present judgment determines the allocation of costs arising from those amendment applications and related interlocutory costs.

Legal Issues Presented

1. Whether, and to what extent, the Plaintiffs should bear the costs of the Eighth and Ninth Defendants' motions to amend their defences given the Plaintiffs' late withdrawal of opposition prior to the scheduled hearing.
2. How consequential costs arising from the amendments (for example, costs of amended replies, particulars or additional discovery) should be allocated between the parties.
3. Whether the circumstances justify departure from the ordinary rule that the amending party bears the costs of a successful application to amend.

Arguments of the Parties

Eighth and Ninth Defendants' Arguments

• The ordinary rule is that the amending party bears the costs of the application; if the Plaintiffs had never opposed, the Defendants would expect to recover costs.
• The Plaintiffs chose to oppose, filed a replying affidavit and sought a hearing date; their opposition was withdrawn only one clear day before the scheduled hearing, by which time substantial costs had been incurred preparing for a contested hearing.
• The Eighth Defendant submitted consequential costs should be limited to the costs of delivering an amended reply; the Ninth Defendant accepted consequential costs would include reasonable particulars or discovery arising from the amendments.
• Any costs occasioned by the amendments that the Plaintiffs can recover should be set off against the Defendants' costs of the motion.

Plaintiffs' Arguments

• The Defendants' grounding affidavits did not adequately explain delay or how logistical prejudice would be addressed, given original defences were delivered in 2022 and discovery exchanged in December 2023.
• The Plaintiffs had little time to take instructions and respond because reply affidavits were received shortly before directions hearings; they sought an early hearing date to progress the case.
• The applications were relatively straightforward (listed for about 90 minutes) and no written legal submissions were filed.
• It would be invidious to place the Plaintiffs in a worse costs position for conceding the applications than if they had contested them; authorities cited by the Defendants involved fully contested hearings, not withdrawals shortly before hearings.
• The Plaintiffs strongly objected to conditioning entitlement to consequential costs on concern they would incur costs unreasonably.

Table of Precedents Cited

Court's Reasoning and Analysis

The court began from the ordinary presumption (as reflected in Order 28 RSC and the case law) that an amending party should bear the costs of a motion to amend and that consequential costs of the amendment are ordinarily borne by the amending party. The Porterridge line of authority requires the court to consider whether opposition was unreasonable and whether an interlocutory application became a substantive separate "event" such that costs should follow the event. The court also accepted authorities permitting apportionment of costs where opposition produced substantially greater preparation and hearing requirements.

Applying those principles to the facts, the court found:

• The Plaintiffs' opposition resulted in the motions being set down for a substantive hearing on 18 December 2025 rather than a short directions appearance.
• The Plaintiffs withdrew opposition on the evening of 16 December 2025, one clear day before the scheduled hearing, by which time most costs for a contested hearing had likely been incurred by the Defendants.
• The Plaintiffs had actively sought an early hearing date, limiting their own time to take instructions and respond; the court treated that as a strategic choice undermining the reasonableness of their late withdrawal.
• Given the timing and conduct, the Plaintiffs' approach was unreasonable in the Porterridge sense and their late concession produced no meaningful savings in costs for the Defendants.

Consequently the court exercised its discretion to apportion costs rather than adhere rigidly to the amending-party-bears-all rule. Taking account of the Defendants' submissions and the authorities, the court considered a 70% recovery by the Defendants to be an appropriate apportionment, leaving a 30% deduction to reflect unavoidable costs incurred by the Defendants in bringing the motions. On consequential costs, the court confirmed that the Plaintiffs are entitled to recover costs "directly and exclusively" occasioned by the amendments (for example, an amended reply), but left the question of particulars or additional discovery to future determination if disputed.

The court also ordered that the costs of the costs hearing on 18 December 2025 be in favour of the Defendants and to be adjudicated in default of agreement, and placed a stay on execution of the costs orders addressed in the judgment pending determination of the substantive proceedings.

Holding and Implications

HOLDING: The court ordered that, in respect of each motion to amend, the Defendants shall recover 70% of the costs of the motions to amend as against the Plaintiffs. The Plaintiffs are entitled to recover consequential costs directly and exclusively occasioned by the amendments (for example, the costs of an amended reply), with disputes about particulars or additional discovery to be determined if they arise. The court ordered that the costs of the costs hearing on 18 December 2025 be awarded to the Defendants to be adjudicated in default of agreement, and placed a stay on execution of the costs orders pending determination of the substantive proceedings.

Implications: The decision apportions costs to reflect the late withdrawal of opposition by the Plaintiffs and the reality that substantial preparation for a contested hearing had already been incurred by the Defendants. The ruling applies established principles (Porterridge and later authorities) on when apportionment is justified; the judgment addresses the parties' practical cost exposure in these proceedings but does not purport to establish a new legal principle.