Proof By Sampling In Construction Disputes

• Published date: 04 November 2022
• Subject Matter: Real Estate and Construction, Construction & Planning
• Law Firm: HKA
• Author: Mr Bob Breeze

It is not uncommon in large construction projects for disputes to arise which involve several thousand alleged variations (or change orders) and/or alleged defects which need to be considered by the arbitral Tribunal or Court in the formal dispute resolution process chosen by the parties.

In addition to the often-extensive factual evidence, this usually gives rise to the need for expert evidence to be adduced dealing with the cause-and-effect liability issues as well as possible delay and quantum claims which arise as a result.

Parties and their appointed experts in many jurisdictions are now required to adopt a proportionate approach whereby they do not "use a sledgehammer to crack a nut" but this can mean different things in different situations. The concept of proportionality is not formulaic in nature.

Being proportionate must often be set against allegations of abuse of process in that not every claim may be considered on its own merits if shortcuts are taken. Despite this, the English Court at least has recently upheld¹ the established position that in principle, a claimant can pursue a claim which relies on sampling for establishing liability or causation of damage, but great care needs to be taken as to how this is executed. Also, whether the sampled answers can be extrapolated to the unsampled population needs careful attention too. This is in line with the Civil Procedural Rules rule 32.1 which confers powers on the Court to control evidence.

The Technology and Construction Court (TCC) Guide² in England requires , before the first case management conference, the parties to give careful thought to expert issues including any "...appropriate or necessary ...sampling". This will often require a discussion between the experts as to an appropriate sampling protocol to be adopted in the proceedings. In these joint expert discussions it is worth bearing in mind what are known as the "Whitford Guidelines"³. For a survey to have evidential value it must be shown that (in that case) the interviewees were selected from a cross section of the population, the survey was of a sufficient size to produce relevant results on a statistical basis, and it was conducted fairly.

Statistical sampling is a method whereby it involves the selection of a subset of items from a larger group (or population) of data claimed and uses the results of this sample to estimate the characteristics of the remainder of the population (i.e., the unsampled data claimed).

The use of...