Hot-tubbing (Concurrent expert evidence)
Hot-tubbing (Concurrent expert evidence)

The following Dispute Resolution guidance note provides comprehensive and up to date legal information covering:

  • Hot-tubbing (Concurrent expert evidence)
  • What is hot-tubbing?
  • Background to hot-tubbing
  • Current position on hot-tubbing
  • When might concurrent expert evidence be suitable?
  • How does concurrent expert evidence work?
  • Concurrent evidence in the Technology and Construction Court (TCC)
  • The pros and cons of concurrent expert evidence
  • Practical tips on giving evidence concurrently
  • Hot-tubbing pilot scheme

What is hot-tubbing?

Concurrent expert evidence ('CEE'), or 'hot-tubbing' as it is colloquially known, is a procedure at trial whereby experts in any discipline give their evidence simultaneously. The process is governed by CPR PD 35, para 11.

The format is usually a discussion chaired by the judge with counsel putting questions to the experts when permitted by the court. The process is intended to be flexible with variations being made depending on the nature of the case.

The giving of expert evidence concurrently is regularly adopted in claims proceeding in the Technology and Construction Court (TCC).

Background to hot-tubbing

The option for expert witnesses, in all civil proceedings, to give their evidence concurrently was introduced to CPR PD 35, para 11 under the April 2013 Jackson Reforms.

Having spoken to various practitioners in Australia who had used hot-tubbing for some time, Lord Justice Jackson 'formed the provisional view that CEE was a cost saving procedure, which merited a Hot-tubbing (Concurrent expert evidence) in England and Wales. If the Hot-tubbing (Concurrent expert evidence) was successful, then it should be introduced generally into our procedure' (Jackson LJ lecture of 29 June 2016—see Related Documents).

Before then, most English court proceedings had tended to favour the adversarial approach of experts giving their evidence sequentially and being cross-examined on it. However, concurrent expert evidence