In Coventry & Warwickshire Development Partnership LLP v Avison Young (UK) Limited [2026] EWHC 2319 (TCC), Eyre J delivered a clear signal that the TCC remains unimpressed by parties “scrabbling around” for natural justice and jurisdictional challenges to resist enforcement, reaffirming the fundamental principle of “pay now, argue later.” The Court enforced an Adjudicator’s Decision of nearly £9 million in damages against a Project Manager (‘PM’) arising from negligent over-certification of interim payments.

Background to Dispute

The Claimant (‘CWDP’) engaged Buckingham Group (‘BGCL’) under an NEC3 ECC Option A for an industrial and logistics park project involving substantial reclamation and remediation earthworks. As Project Manager, Avison Young (‘AY’) was tasked with interim certification of sums due. Following the insolvency of BGCL, CWDP alleged that it had overpaid BGCL due to AY’s professional negligence regarding the over-certification and commenced an adjudication.

Unusually, this judgment helpfully provides lengthy extracts from the adjudication submissions. The Referral stated that CWDP claimed “damages representing the loss arising from AY’s breaches” for professional negligence. CWDP said it had relied on AY’s assessments of the PWDD in making payments to BGCL under the Contract and therefore paid BGCL £25,374,883.84 more than the proper value of the works completed.

The Adjudicator’s Decision set out the dispute as follows: “The dispute is whether AY failed properly to assess the amount due to BGCL in accordance with clause 50.1 of the Main Contract. CWDP alleges that AY failed to perform the duties that AY owed to CWDP properly and with the required standard of skill and care; more particularly, that it failed properly to: (a) assess the amounts due to BGCL (the Price for Work Done to Date (“PWDD”)) with an acceptable degree of accuracy; and/or (b) identify Defects in BGCL’s Works in its role of Supervisor. I am required, if I conclude that AY did so fail, to determine the consequence of that/those failures.”

The Adjudicator summarized three criticisms from the Referring party on the approach which the PM had taken in performing its role before concluding that “these all seem to me valid criticisms”. On the evidence he stated that: “… AY was prepared to accept largely at face value the progress information placed before it by BGCL, which in turn coincided with the PEE quantities [‘Permits, Equipment, and Earthworks Data’ which recorded excavation volumes]… both Experts agree that the EPD [‘Earthworks Production Data’] is the primary source of data for calculating the volumes of material placed into the environmental bund…”

The Adjudicator then considered what the correct assessment should be, including: the effects of recovery under a performance bond; retention; defects; and termination. He concluded that AY failed to carry out its duties under the Appointment to the required standard of skill and care, leading to its significant over-certification of the Price for Work Done to Date due to BGCL before Completion.

His redress set out: “(a) in its payment certificate No. 37 issued 3 February 2023, AY over-valued the cumulative Price for Work Done to Date at that time; (b) the extent of the over-valuation by AY … was no less than £7,694,883.73; (c) as a result of AY’s over-valuation, CWDP has suffered a loss of £8,729,179.33, inclusive of interest; (d) AY is liable to compensate CWDP by way of damages in respect of that loss.”

Adequacy of Reasons

AY challenged enforcement on the basis that the decision contained inadequate reasons. Eyre J cited Thermal Energy Construction Ltd v AE & E Lentjes UK Ltd [2009] EWHC 408 (TCC) to qualify the obligation to give reasons in the adjudication arena: “…the fact remains that an Adjudicator is obliged to give reasons so as to make it clear that he has decided all of the essential issues which he must decide as being issues properly put before him by the parties, and so that the parties can understand, in the context of the adjudication procedure, what it is that the Adjudicator has decided and why.”

The Judge further explained that the “reasons for an Adjudicator’s decision can be expressed briefly” and that the Adjudicator is not required “to address all the arguments advanced on a given issue.” He concluded that a “party who can say in detail how an Adjudicator erred will find it hard to show that the reasons given did not enable that party to understand what the Adjudicator had decided and why.”

Applying these principles, Eyre J rejected AY’s contention, stating: “The Decision did not address breach, causation, and loss in separate sections in the way which might have been done in a judgment but from reading the Decision as a whole it was clear both that the Adjudicator was addressing those matters and why he had reached his conclusions.”

Addressing the Dispute Referred & Excess Jurisdiction

A core tenet of adjudication enforcement is the distinction between a wrong answer (an error of law or fact within jurisdiction) and answering the wrong question (an excess of jurisdiction). If an Adjudicator asks the relevant question, the resulting decision is enforceable, regardless of its perceived correctness.

AY’s first contention was that by using quantities to calculate the award, the Adjudicator had conducted a valuation exercise rather than a negligence assessment, thus answering a question not referred to him. The Response included similar posturing: “As such, before considering any of the quantum analysis by the parties’ appointed experts, the Adjudicator must first find that AY did not act reasonably in performance of its contractual duty when assessing the sums due to BGCL.”

Eyre J rejected this characterization noting that the Adjudicator explicitly drew a distinction between the “extent to which Buckingham had been overpaid” and the “consequences of the Defendant’s failure to perform its duties.” The Court found that by using quantities and valuations, the Adjudicator was not departing from the referred dispute; he was employing a proxy methodology to quantify the loss flowing from the professional negligence.

AY’s second contention was that in order for the Adjudicator to determine a breach of duty it was a necessary first step to establish whether the amount which it had certified to BGCL was outside the range of amounts which could properly have been certified by a competent PM exercising proper care and skill.  AY asserted this was a “pre-condition to liability”, citing Bratt v Jones [2025] EWCA Civ 562.

This defence also failed with the Judge noting obiter comments in Bratt which cast some doubt on any “absolute” pre-condition and, in any event, he stated that: “At their highest the points made by the Defendant in this regard amount to showing that the Adjudicator addressed the right question but did so in the wrong way.”

Canvassing Views and Natural Justice

In Cantillon Ltd v Urvasco Ltd [2008] EWHC 282 (TCC), Akenhead J set out the definitive test: “It is only if the Adjudicator goes off on a frolic of his own, that is wishing to decide a case upon a factual or legal basis which has not been argued or put forward by either side, without giving the parties an opportunity to comment or, where relevant put in further evidence…”

In the underlying decision, where the parties’ experts were agreed on valuation, the Adjudicator adopted their figures; where they diverged, he derived figures from an intermediary source—a termination account produced by Gardiner & Theobald (‘G&T Assessment’). AY alleged a material breach of natural justice, claiming that the Adjudicator relied upon the G&T Assessment as a primary calculation basis without giving the parties an adequate opportunity to address it.

Eyre J detailed exchanges from December 2025 to January 2026, which demonstrated the extent to which the Adjudicator canvassed his alternative view. The court found that the Adjudicator avoided a material breach by providing clear forewarning and “ample opportunity” for the parties to comment, including that the Adjudicator went so far as to offer a joint meeting to discuss the G&T data.

Briefly, regarding retention and defects, the Court was not persuaded by any natural justice issue, stating that the Adjudicator exercised an approach held to be appropriate in Roe Brickwork Ltd v Wates Construction Ltd [2013] EWHC 3417 (TCC). That is to say, he considered the parties’ argument, he accepted aspects of each and then he reached a conclusion based on those aspects which he had accepted. The Judge stated that the approach taken was far removed from the objectionable course of “deciding the point on material which had not been considered by the parties or on a basis which the parties had not had an opportunity to address.”

Further Discussion – Rejection of Canvassed Alternative Views

When an Adjudicator adopts an alternative view, methodology, or legal construction, without sufficiently canvassing the parties, there is invariably a challenge under both natural justice and jurisdiction. However, what about the premise where an Adjudicator adopts an alternative view with sufficient canvassing and, as happened here, the Responding Party states the evidence is “not relevant” and the Referring Party states that the Adjudicator “should not approach the matter on that basis”.

Albeit not in respect of canvassed submissions, the relevant jurisdictional boundary was considered in Primus Build Ltd v Pompey Centre Ltd [2009] EWHC 1487 (TCC), where Coulson J (as he then was), by applying Shimizu Europe Ltd v LBJ Fabrications Ltd [2003] BLR 381, found the Adjudicator had acted in excess of jurisdiction by taking an alternative approach the parties had instructed him to “ignore”:

“There, the learned judge concluded that the parties had agreed that their contractual relationship was governed by a letter of intent (“LOI”). She therefore found that the Adjudicator had exceeded his jurisdiction by deciding that the DOM/1 Form had been incorporated instead … Accordingly, I find that both parties were agreeing that, to use Primus’s own word, the accounts should be “ignored”. Thus I conclude that the Adjudicator did not have the jurisdiction to consider those accounts or make any findings based upon them. The parties had reached a similar sort of agreement to that reached by the parties in Shimizu and for the same reasons the Adjudicator ought not to have gone beyond that agreement.”

With canvassing and natural justice, Roe Brickwork, at paragraph 24, provides that the Adjudicator is not restricted in choosing between the binary positions of the parties: “there is no rule that… an Adjudicator must decide a case only by accepting the submissions of one party or the other. An Adjudicator can reach a decision on a point of importance on the material before him on a basis for which neither party has contended, provided that the parties were aware of the relevant material and the issues to which it gave rise had been fairly canvassed before the Adjudicator.”

To summarise, on the one hand, an Adjudicator must not exceed jurisdiction by considering matters which the Adjudicator is instructed to “ignore”, and, on the other hand, an Adjudicator can reach a decision on a point that neither party has contended, providing the parties were canvassed. With this internal conflict, it is submitted that by simply ‘adequately canvassing’, there is no obvious rationale to allow an Adjudicator to act in excess of jurisdiction and/or to extend the Adjudicator’s jurisdiction. Therefore, it is submitted in respect of adequately canvassed, alternative views, subsequently rejected by the parties, there are in fact jurisdictional limits to the principle in Roe Brickwork and the following boundary might be identified:

Mere Disagreement is Insufficient: This judgment suggests that it is insufficient for the parties merely to insist that the adjudicator is wrong or to dispute the relevance of the underlying material. This applies a fortiori with an intermediary position, which both parties would be naturally inclined to reject.  

Explicit Restriction Required (the Primus principle): To successfully divest an adjudicator of jurisdiction over a canvassed methodology, the parties must make an explicit jurisdictional objection or, at a minimum, instruct the adjudicator to “ignore” the point entirely.