Hitachi Zosen Inova AG v John Sisk & Son Ltd

In successive adjudications, the critical comparison is between what the first adjudicator actually decided and what is later referred. A later dispute is not barred merely because it concerns the same contractual event, uses overlapping evidence, or seeks the same remedy. Where the first adjudicator declined to value a variation because the evidence was insufficient for the particular interim application, a later adjudicator may value that variation on fuller substantiation. The temporary or contractual finality of an adjudication decision extends only to matters actually decided.

Hitachi engaged Sisk under a construction contract containing provisions for variations, substantiation of additional cost, interim payment applications and adjudication. In the second adjudication, the adjudicator decided that Event 1176 was a variation requiring valuation, but awarded nil for the relevant payment application because Sisk had not provided sufficient evidence to value it. Sisk later supplied substantially fuller evidence and referred the valuation of Event 1176 to an eighth adjudication. The adjudicator held that he had jurisdiction and awarded Sisk £825,703.17 plus interest. Hitachi sought to prevent enforcement, arguing that the eighth adjudication concerned the same or substantially the same dispute.

1. The adjudicator in the eighth adjudication had jurisdiction to evaluate Event 1176, and his orders fell to be enforced.
2. The governing question was what the first adjudicator actually decided. The scope of the referral was relevant, but could not substitute for analysis of the decision itself.
3. The second adjudicator decided that Event 1176 was a variation requiring valuation and that no sum was payable for Payment Application 6 because the substantiation then available was inadequate. The nil figure was not a valuation of the variation for all contractual purposes. The question of value on a subsequent application was left open.
4. The eighth adjudication concerned valuation on fuller evidence. It was therefore neither the same nor substantially the same dispute. Overlap in evidence and the fact that both adjudications concerned the same event did not alter that conclusion.
5. Finality attached only to the dispute actually decided. The consequences of Hitachi’s construction would create a contractual trip-wire requiring clear language and would sit uneasily with the contractual power to adjust previous over- or under-payments and with adjudication’s cash-flow purpose.
6. The estoppel argument did not require determination. Had it mattered, no estoppel or other bar would have been established merely from the parties’ conduct in the later mediation or sixth adjudication.