The proceedings offer a useful, if pointed, restatement of orthodox principles governing the adjudicator’s “opening up” jurisdiction - while also exposing the conceptual tension between prospective contractual mechanisms and retrospective dispute resolution.
The dispute arose under an amended JCT Design & Build 2016 contract for substantial refurbishment works to a listed building. The adjudicator, invoking paragraph 20A of the Scheme for Construction Contracts, opened up, reviewed, and ultimately reversed the Employer’s Agent’s decision, stripping away the previously granted extensions. This had the practical effect of reinstating an earlier completion date. The Contractor’s response was to bring Part 8 proceedings seeking declaratory relief on certain matters of contractual interpretation in addition to a declaration to the effect that neither an adjudicator nor a court has the jurisdiction to set a completion date earlier than the one established by the Employer’s Agent. Had the Contractor succeeded in respect of this declaration, the Adjudicator’s decision would have been made ultra vires by the powers conferred by the Scheme.
The court, however, declined to grant the relief sought. In doing so, it reaffirmed a well-established principle: decisions, certificates, and determinations made under construction contracts (unless expressed to be final or conclusive) are binding only on an interim basis (pro tempore) and are susceptible to review and revision in subsequent proceedings. This principle is deeply embedded in construction law and reflects the industry’s preference for temporary cash flow certainty coupled with the ability to revisit correctness later.
Interestingly, the Contractor’s argument focused on the nature of the extension of time mechanism. Under standard JCT provisions (not modified in this instance), the Employer’s Agent is typically required to undertake a prospective assessment of delay, based on notices and particulars provided at the relevant time. The Contractor argued that this prospective character imposed a conceptual limit: once an extension had been granted, it could not later be “unwound” to produce an earlier completion date, as this would involve a retrospective reassessment alien to the contractual machinery.
But the problem with that analysis is twofold. Take, for example, a simple arithmetical error. Supposing an Employer’s Agent, intending to award 10.5 days, misplaces a decimal point and awards 105 days. On the Contractor’s case, that determination, once made, would set a floor beneath which no subsequent decision maker – adjudicator or court – could descend. The error could be corrected upwards (if say, the Contractor later persuaded a tribunal that even 105 days was insufficient), but not downwards. The consequence is obvious: a plainly wrong completion date, produced by a clerical slip, becomes effectively immunised from correction.
It would mean that the interim machinery of the contract, intended to facilitate contract administration, could, by complete accident, lead to a windfall in the Contractor’s entitlement, with no meaningful mechanism for correction. It also sits uneasily with the well-established rule that certificates and decisions are (unless by operation of the contract final and binding) interim binding.
A more nuanced example sharpens the point further. Suppose the contract requires the Employer’s Agent to assess delay by reference to critical path analysis, to consider concurrency in a particular way, and to consider the Contractor’s own culpability at the incidence of delay. Instead, the Employer’s Agent adopts a rough and ready approach and eschews any causation analysis, awarding a generous extension of time untethered from the relevant contractual entitlement – a ‘gratuitous’ extension of time in any meaningful sense.
If the Contractor was right, that flawed exercise would create a one-way ratchet. However egregious the departure from the contract, however disconnected the award from actual delay, the resulting completion date could not be revisited so as to reduce the extension. Again, it could be increased but never pared back. The Adjudicator’s jurisdiction under Para. 20A of the Scheme would be hollowed out at precisely the point where it is needed most: the correcting of errors.
Such a position conflates two ideas. The requirement to carry out a prospective assessment governs how the assessment of an extension of time ought to be made, but it does not limit whether it can be revisited.
The court acknowledged that the argument raised “novel issues”, but ultimately rejected it. The key lay in the breadth of paragraph 20A of the Scheme, which expressly empowers adjudicators to “open up, review and revise” any certificate or decision. That language is deliberately expansive and has long been understood to permit a wholesale reconsideration of earlier determinations, including those relating to time.
Importantly, the court drew a distinction between the existence of the power and the manner of its exercise. While an adjudicator may revisit an extension of time decision, the exercise must still be rooted in the contractual framework. Here, that meant undertaking the assessment in accordance with the relevant clause, i.e. as a prospective evaluation based on the notices and particulars submitted. In other words, the adjudicator steps into the shoes of the Employer’s Agent and performs the same task, rather than conducting a free-ranging retrospective analysis unconstrained by the contract.
This gives rise to an apparent tension. On the one hand, adjudication is inherently retrospective: it occurs after events have unfolded and disputes have crystallised. On the other, the contractual mechanism being applied may require a prospective lens. The court’s answer was pragmatic. It accepted that this may create “difficulties” for adjudicators - particularly where later evidence sheds light on the true impact of events - but saw no principled objection. The adjudicator must, in effect, ignore the benefit of hindsight to the extent the contract demands.
From a practical perspective, the decision reinforces that parties should be slow to assume that earlier favourable determinations - whether by an Employer’s Agent or otherwise - are insulated from reversal. The “open up, review and revise” jurisdiction remains potent and can operate to the detriment of either side. It confirms that adjudicators possess a wide jurisdiction to revisit prior decisions, including those on time, but must exercise that jurisdiction within the confines of the contract.
The result is a careful balancing act: preserving the integrity of contractual mechanisms while ensuring that interim decisions remain open to correction.
The Employer was represented by Jessica Stephens KC of 4 Pump Court, instructed by Yolanda Walker (Partner), David Humphreys (Senior Associate) and Alice Sleep (Solicitor).
If you have any questions regarding points raised above, or how this may impact your business, please contact the authors below.
