Adjudication enforcement in focus: When is an agreement agreed?

Project correspondence may refer to certain items being "agreed", but that does not necessarily mean the parties have entered into a legally binding agreement varying the contract. In Clerkenwell Lifestyle v HG Construction, the Technology and Construction Court (TCC) considered whether emails recording a 12-week extension of time (EOT) constituted a binding agreement fixing revised completion dates, or simply formed part of the contractual EOT mechanism. Looking beyond the language used in the correspondence, the Court examined the wider factual context, including the procedure being followed and the parties' subsequent conduct. The case also highlights the difficulties parties face when seeking to challenge enforcement of an adjudicator's decision on the basis of arguments that were not clearly put before the adjudicator.

What led to the dispute?

Clerkenwell engaged HG, under an amended JCT Design and Build Contract 2016, for a hotel and affordable housing development in Clerkenwell, London.  

At various points during 2022, HG reported delays to the Works. The principal causes of delay were a Covid-19 outbreak, transport strikes, adverse weather conditions and issues with material sourcing and delivery. In response, the Employer's Agent, Avison Young granted a number of EOTs and revised the sectional completion dates. The delays were subsequently discussed in a series of email exchanges between December 2022 and February 2023.  On 8 February 2023 Avison Young confirmed by email:

• A 12-week EOT would be granted under the Contract in recognition of adverse weather conditions and industrial action.  
• The sectional completion dates were to be revised accordingly.
• HG would not seek any additional payment for the extra time granted under the 12-week EOT and agreed not to claim compensation for the costs it incurred as a result of the delay.  

A dispute later arose over entitlement to further EOTs and liability for LDs. HG sought further EOTs by reason of design changes, the impact of Covid-19, changes to the Works and delays in certifying practical completion caused by the surveyors. Rather than granting any further EOTs, Avison Young issued a non-completion notice and gave notice that Clerkenwell would require payment of or would deduct liquidated damages for delay (LDs). Clerkenwell subsequently withheld £500,000 in LDs from sums otherwise due to HG and sought payment of a further £1 million. HG disputed this, maintaining that further EOTs should have been granted. Clerkenwell then commenced an adjudication to determine the correct completion dates and recover £1 million in LDs, arguing that HG had already been granted more EOT than it was entitled to.

In his decision, the Adjudicator (Mr Matt Molloy) identified the dispute as concerning HG's entitlement to an EOT and Clerkenwell's entitlement to LDs. The Adjudicator ultimately decided:

• HG was entitled to an EOT of 186 days for the affordable housing development and 123 days for the hotel; and
• Clerkenwell was entitled to £955,943.43 LDs.

After the decision was issued, HG made further submissions to the Adjudicator, asking that he correct it. HG argued that the parties had already reached a binding settlement agreement (as set out in Avison Young's February 2023 email) and the Adjudicator did not have the authority to overturn it. On that basis, HG contended that any further EOTs should have been applied to the revised completion dates established in February 2023, rather than to the original completion dates set out in the contract.  

HG asked the Adjudicator to amend the decision under the "slip rule", which allows minor errors in a decision to be corrected. The Adjudicator rejected the request, stating that there was no error to correct.

The enforcement challenge

After the Adjudicator declined to amend the decision, HG commenced Part 8 proceedings seeking to set the Decision aside. HG's challenge centred on two arguments:  

1. That there was a binding agreement between the parties regarding EOT entitlement, per the email correspondence from February 2023.
2. The Adjudicator failed to take account of the parties' binding agreement and should not have revisited that issue. By revisiting the issue, the Adjudicator acted unfairly and went beyond the matters he was entitled to decide.

 Clerkenwell meanwhile pursued enforcement of the Decision under Part 7.  The TCC considered both claims together.

The decision

Jefford J dismissed HG's arguments that the Adjudicator had exceeded the scope of the dispute referred to him, or that he had acted unfairly, and confirmed that the Decision would be enforced.  

Key decision 1: Acting fairly

The adjudication concerned the parties' entitlements to EOTs, and liability for LDs, which were matters the Adjudicator was entitled to determine. The Court held that these issues had been referred to the Adjudicator in "broad terms" and HG had participated in the adjudication on that basis.  

The Court held that a challenge based on an adjudicator's failure to consider a particular point can only succeed where that point was properly put before the adjudicator in the first place. The only material relied upon by HG was a reference in its Response to the February 2023 email exchange and the fact the EOT had been "agreed". The Court considered this did not come close to asserting the parties had entered into a separate binding agreement fixing revised completion dates that the Adjudicator was required to adopt. As no declaration based on such an agreement was sought, the Court held HG could not later argue that the Adjudicator had failed to consider it.

The Court was also influenced by the way HG had presented its delay case during the adjudication. Its expert analysis proceeded on the basis of the original contractual completion dates, which sat uneasily with the later contention that revised completion dates had already been fixed by agreement.  

Against that background, the Court concluded that the Adjudicator had addressed the issues placed before him and had not exceeded the bounds of the referral. There was, therefore, no breach of natural justice and no basis for refusing enforcement of the Decision.  

Key decision 2: No binding agreement

The TCC also found that the email exchanges in February 2023 did not give rise to a binding agreement. While the emails referred to an "agreed" extension of time and the parties undoubtedly reached a consensus that a 12-week extension should be granted, the Court held that the language of "agreement" was being used in a practical sense. It reflected the parties' willingness to proceed with the contractual extension of time process, rather than an intention to create a new independent contract outside the terms of the building contract.  

The wider factual background reinforced the Court's conclusion. Reviewing correspondence from December 2022, the parties had discussed the period of extension that would be acceptable and HG was asked to submit a formal EOT application. Avison Young indicated that this extension would then be granted. This showed the parties were operating the contractual mechanism for an EOT, rather than negotiating a standalone agreement to amend the completion dates. This was further supported by the lack of sufficient clarity in the communications as to their legal effect, together with the parties' subsequent conduct which was inconsistent with any binding variation having been agreed.  

Key takeaways  

Clerkenwell Lifestyle v HG Construction highlights the risks of relying on project correspondence to establish legally binding agreements and reinforces the importance of advancing all material arguments during an adjudication. The decision demonstrates the difficulties that can arise where parties seek to rely on project communications to establish contractual agreement without clear and unequivocal wording.  

1. Informal agreements on delay and completion dates can create significant uncertainty. The central issue in the case was whether an email exchange had created a binding agreement to revise the completion dates. The court concluded they had not. For construction professionals, the practical lesson is straightforward: where parties intend to agree an EOT and/or revise completion dates, the position should be recorded clearly.  Where parties intend to change something which is written into a contract, it should be implemented as a formal contractual variation, in accordance with the relevant contractual requirements. Parties should be cautious about relying on informal exchanges of correspondence to record agreements with significant contractual consequences.
2. Raise all key arguments during the adjudication. HG's challenge failed in part because it had not clearly advanced the alleged binding agreement during the adjudication. Parties should ensure that all legal arguments are expressly pleaded and supported during the adjudication procedure. An attempt to rely on them later in enforcement procedures is unlikely to be successful.
3. Ensure your case is consistent. The TCC was influenced by the fact HG's later arguments were difficult to reconcile with the expert evidence relied upon during the adjudication. Parties should ensure their legal arguments, witness evidence and expert evidence are aligned and support a coherent overall case.

If you have any questions about the subjects discussed in this article, please contact Chloe Somerwill, Katherine Doran or your usual contact at TLT.

Authors: Chloe Somerwill and Katherine Doran

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at September 2026. For more information see our terms & conditions.