Plymouth South West Co-Operative Society Ltd. v ASM

Expert evidence supporting a substantial construction claim must provide a sufficiently particularised and intelligible basis for the figures advanced. Where an expert’s answers remain inadequate, the court may require amendments, further clarification and an experts’ meeting before deciding whether evidence should be excluded or pleadings struck out. Strike-out or debarring orders should not be made prematurely where the court cannot yet assess the extent of prejudice, particularly where the opposing expert has not identified any material inability to respond. Case management must remain consistent with the overriding objective, while ensuring that a party is not permitted to proceed to trial on an incoherent or inadequately particularised case.

The claimant brought a claim exceeding £3 million against architects arising from the refurbishment and subdivision of a store. The claim had been reduced to approximately £2.1 million, based principally on an alleged reasonable cost of £6.7 million compared with the actual cost of £8.6 million.

Following earlier case-management orders, the claimant served a Scott Schedule and expert evidence from a quantity surveyor. The defendant contended that the breakdown of the £6.7 million figure was inadequate and applied to strike out that figure or debar the expert from relying on parts of his report. The central issue was whether the deficiencies justified immediate exclusion of the evidence or striking out of the pleaded claim.

1. The application to strike out the pleaded £6.7 million figure, or to debar the claimant’s quantity surveyor from relying on the relevant parts of his report, was adjourned rather than granted or dismissed.
2. The claimant’s expert evidence was presently unsatisfactory. The expert had given largely unparticularised estimates, had failed to provide an adequate audit trail, and appeared to have confused actual project costs with the hypothetical reasonable cost exercise required by the claim. A reasonable cost assessment should ordinarily be calculated from first principles, using actual costs only where they provide assistance or corroboration.
3. It was not appropriate for the defendant’s expert to undertake the slow and expensive process of extracting information which should have been supplied by the claimant’s expert. Nevertheless, immediate strike-out was inappropriate because the court did not yet know whether the defendant’s expert was genuinely unable to deal with the individual items or had suffered material prejudice. His supplementary report did not identify such difficulties.
4. Applying the overriding objective, the court required the claimant to provide draft pleading amendments consistent with its expert report and containing as much detail as possible concerning the £6.7 million breakdown. The quantity surveying experts were ordered to prepare a note identifying matters of agreement and disagreement under Civil Procedure Rules 1998 Part 35.
5. The application was adjourned to be heard with the parties’ other case-management and pre-trial review matters. The question of costs was also adjourned.