Technology and Construction Court reinforces the high threshold for challenging adjudicators' decisions: Coventry & Warwickshire v Avison Young

In Coventry & Warwickshire Development Partnership LLP v Avison Young (UK), the court considered four common grounds for resisting enforcement of an adjudicator's decision:

whether the adjudicator acted outside of his jurisdiction by adopting his own valuation;
whether his reasons were adequate;
whether reliance on third-party material gave rise to a breach of natural justice; and,
whether any defective parts of the decision could be severed.

The judgment provides useful guidance on the limits of these challenges and reinforces the high threshold parties must overcome to avoid enforcement.

Background

Coventry & Warwickshire engaged Avison Young as project manager and supervisor under an NEC3 ECC Option A contract concerning the development of an industrial and logistics park at Gateway South in Coventry. A dispute arose between the parties in relation to the certification of the sums due on the monthly payment applications. Coventry & Warwickshire alleged that Avison Young:

significantly over-valued the amounts that were due to the contractor,
wrongly accepted the contractor’s assertion of the extent of the work performed, and
failed to identify the defects in the work that had been completed.

Avison Young rejected this position and Coventry & Warwickshire subsequently referred the matter to adjudication.

The adjudication

The adjudicator adopted a less conventional analytical approach, structuring his analysis around the valuation and certification process. In doing so, questions of breach and causation were considered as integral aspects of the valuation exercise rather than as distinct stages in isolation.

The adjudicator reached his decision on 13 February 2026, determining that Avison Young failed to properly assess the amount due in accordance with the contract and failed to perform its duties with the required standard of skill and care. The adjudicator therefore awarded Coventry & Warwickshire circa £8.7 million plus interest as damages. However, Avison Young subsequently resisted enforcement of the decision, giving rise to proceedings before the Technology and Construction Court

The enforcement proceedings

Following adjudicator's decision, Avison Young challenged enforcement on four grounds relating to jurisdiction, adequacy of reasons, natural justice and severance. The court rejected each argument and enforced the decision.

1. The adjudicator did not act outside of his jurisdiction by undertaking his own valuation of the sums and therefore had not failed to address the dispute that was referred to him.

The adjudicator found that the parties’ competing valuation evidence was not determinative in all respects and therefore undertook his own assessment of the quantities and valuation material, including using figures derived from the Gardiner & Theobald Assessment (a post-termination valuation d) where the parties’ experts disagreed. The court rejected Avison Young’s jurisdiction challenge and found that the adjudicator decided the dispute he was asked to decide. The adjudicator's valuation exercise was a means of determining the loss allegedly caused by Avison Young's conduct, not a separate dispute. The adjudicator was assessing Avison Young's performance as project manager, not carrying out a fresh valuation of the works.

2. The adjudicator had given adequate reasons for his decision.

The adjudicator concluded that Avison Young had failed to perform its duties with the required standard of skill and care, resulting in significant over-certification of the sums due to the contractor prior to completion. This was then followed by a “quantum summary” of his decision.

The court confirmed that an adjudicator’s decision can be expressed briefly, provided the decision, which must be read as a whole, enables the parties to understand what has been decided and why. The court found that the adjudicator's reasoning was clear enough for the parties to understand his conclusions and how he reached them.

3. The adjudicator was not in breach of natural justice for having taken account of third-party assessment documents that were produced.

The adjudicator considered that the Gardiner & Theobald Assessment could assist in resolving areas of disagreement between the experts. He raised its potential relevance with the parties, explained how he proposed to use it, invited further submissions, and offered a meeting to discuss the issue before reaching his decision.

The Court referred to Premier Modular Ltd v Maidstone and Tunbridge Wells NHS Trust, which highlights the high bar that must be met before an adjudicator will be found to have departed from the parties' cases and effectively gone "off on a frolic of their own". An adjudicator does not breach natural justice simply because they reach a conclusion that neither party advanced. The critical question is whether the parties had a fair opportunity to address the material relied upon.

4. Severance did not apply here as it cannot be used to challenge findings that a party simply disagrees with.

The court found that Avison Young was not really seeking severance of alleged unenforceable parts of the decision. Instead, it was asking the court to overturn parts of the adjudicator's findings and recalculate the award on a different basis. The court made clear that severance is not a mechanism for challenging findings that a party simply disagrees with.

In the absence of any jurisdictional error or breach of natural justice, the decision remained enforceable as a whole, even if Avison Young considered parts of it to be wrong.

Key takeaways

This decision reinforces the Technology and Construction Court’s pro-enforcement approach to adjudication. For construction professionals, it highlights that:

Challenges based on jurisdiction, adequacy of reasons or natural justice remain difficult to establish and will only succeed in exceptional cases.
Adjudicators are entitled to reach their own conclusions, including by accepting parts of each party's case and rejecting others.
A decision will not be unenforceable simply because an adjudicator adopts an analytical approach that differs from that advanced by the parties.
Attempts to reargue the merits of an adjudicator's conclusions under the guise of severance are unlikely to be favoured by the court.

Ultimately, the judgment serves as a reminder that adjudicators' decisions will generally be enforced, even where a party disagrees with the outcome, provided the adjudicator has acted within their jurisdiction and in accordance with the requirements of natural justice.

For more information, please contact our construction team.