J Sainsbury Plc & Anor v WSP Consulting Engineers Plc & Anor

Late amendments to pleadings may be permitted where any prejudice can be remedied by costs. An amendment should nevertheless be refused if it is irrelevant to the pleaded case or cannot affect the recoverable loss. Where a claimant could have invoked contractual remedial rights at the defendant’s expense, a mitigation argument based on the hypothetical cost of exercising those rights may be irrelevant because the claimant would have incurred no payment. An amendment advancing a possible credit for an unbuilt extension may be allowed where its factual and financial consequences can be addressed later in the trial.

The claimants sought damages arising from defective foundation design for a supermarket. During the fourth day of trial, WSP applied to amend its defence and related pleadings in two respects.

1. The first proposed amendment altered the alleged measure of loss by relying on the estimated cost of completing remedial Soilfrac works.
2. The second quantified a proposed credit for the cost of an extension which had been planned but never built.

The claimants also applied to delete two sentences from their response to a request for further information concerning the abandoned extension. The court had to determine whether the proposed amendments were relevant and whether their lateness caused irremediable prejudice.

1. Measure of loss amendment refused. The proposed amendment was irrelevant. The existing defence alleged that the claimants had failed to mitigate by requiring Keller to return under its contract. It was common ground that, if that contractual right had been exercised, WSP would have paid the resulting costs and the claimants would have paid nothing. A successful mitigation defence would therefore result in the claimants recovering nothing, rather than recovering the hypothetical cost of carrying out the remedial works.
2. Late amendments. The court applied the longstanding principle that amendments may be permitted where any resulting injustice can be remedied by an appropriate order for costs. That principle did not assist the measure-of-loss amendment because the amendment itself was irrelevant.
3. Extension amendment permitted. WSP was permitted to quantify the alleged credit for the cost of the unbuilt extension. The figure was derived from a detailed costing prepared by quantity surveyors. Although the amendment was late and the experts had not fully considered it, the material could be addressed during the remaining trial.
4. Consequential issues reserved. If the claimants sought a consequential amendment to claim profits allegedly lost because the extension was not built, the court would consider that issue when properly formulated. It remained uncertain whether the claim would ultimately be relevant, and assessment might require separate case management.
5. Claimants’ deletion application refused. The court declined to strike out the two sentences concerning causation of the abandoned extension. The issue depended on disclosed documents and forthcoming oral evidence. The claimants’ case was sufficiently clear, so deletion was unnecessary and inappropriate.

Not stated in the judgment.