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The single joint expert process - a specialist's view

Jay Shaw Jay Shaw

In New Zealand relationship property proceedings, forensic accountants and other expert witnesses are almost always appointed on behalf of one of the parties (a ‘party appointed expert’, or PAE).  In comparison, where expert evidence is required in matrimonial cases in the United Kingdom and Australia, the parties normally jointly appoint a single expert (a ‘single joint expert’, or SJE).

Having been engaged as a SJE on valuation and other financial matters for family law proceedings in both NZ and the UK, I have seen the SJE approach deliver significant time and cost savings. While there are certainly risks to this approach (you may ultimately end up with three experts), there is considerable scope for its increased use in NZ - particularly for lower value, less complex matters.

How is the SJE process governed in the UK?

In the UK, the appointment of experts in family law proceedings is governed by law (specifically, Part 25 of the Family Procedure Rules 2010 (FPR) and the associated Practice Direction 25D[1]).  These documents set out a broad procedural framework covering all core matters, including appointment, fees, information disclosure, reporting requirements and timetable.

The general position of the FPR is that SJEs should be appointed rather than PAEs, and the UK Courts have actively supported this approach. Even if the parties wish to appoint their own experts, the Court can over-ride their wishes and order them to instruct a SJE instead.

Where a SJE is appointed and produces a report, either party can still seek leave to obtain a second report from a PAE. However, for that PAE report to be accepted as evidence by the Court the party would almost certainly need to show that:

  • the SJE had been unable to resolve the issue
  • there were substantial sums and complex issues involved
  • the request was legitimate and proportionate[2].

The overriding duty of the expert is of course the same under either approach. Their primary duty is to the court, and it overrides any obligation to the person who instructs them or pays their fees.

At present there is no established SJE regime in NZ. At this stage a separating couple wishing to appoint an SJE would need to agree their own procedure to do so, possibly modelled on the UK or Australian regimes. The use of an expert familiar with SJE processes is also likely to be of benefit.

So how does the SJE process work?

The SJE approach can deliver significant time and cost savings, but it also raises some issues that need to be carefully managed to ensure an effective process.

Time and cost savings

Usually only one expert report is required under the SJE approach, followed by written answers to any subsequent questions from the parties. This makes the process much quicker and less costly than using PAEs, which usually requires a report from each expert and often reply or supplemental briefs, followed by expert meetings and a joint statement. In some cases the costs of an SJE can actually be less than one of the PAEs appointed under that approach.

The reduced volume of evidence also cuts down the length of time the expert needs to be involved in the process. Even for relatively complex assignments the SJE approach usually takes less than three months from the date of instruction to providing written responses to any questions, assuming timely disclosure of information. And because the expert is appointed by both parties, it is usually quicker and easier to access all the information required to complete the work.

Issues to be aware of
The time and cost benefits of a SJE approach are attractive, but there are some issues to consider. Whilst some of these issues are definite disadvantages, others arise due a lack of familiarity of advisors used to a PAE approach.

The SJE approach tends to be less suited to complex or novel situations, where the courts might prefer to see a range of views discussed and debated by more than one expert. However, only a small number of cases fall into this category.

Very high value assignments also tend to be less suited as, due to the sums involved, shadow experts are often instructed to provide a “second opinion”.  Any possible cost savings disappear very quickly once additional experts are engaged.

Tension can arise during the SJE process, as legal advisors for both parties have to work together to instruct the expert, whilst continuing to protect their own clients interests. This can lead to:

  • Lengthy negotiations over who to appoint, their instructions and their fees
  • Disagreement over the appropriate factual information to be given to the expert
  • Disagreement about the questions to be asked in response to the expert’s report (particularly if these are seen as extending the initial instructions)

Communication channels are also more open, formal and structured than under a PAE approach. The expert must send any communications to all parties, and any discussions with the expert must be documented and shared with everyone. The overriding considerations are fairness and transparency and the process can quickly derail if there is any suspicion these principles are not being upheld (for example, if the expert were to interview one spouse, but not the other).

Finally, there is an overriding risk the SJE process will fail, simply because one or both of the parties does not agree with the outcome and refuses to settle on that basis. Sadly, this is likely to result in an extended litigation process and the involvement of three experts, rather than one or two.


Appointing a SJE, rather a separate expert for each party, can deliver clear time and cost savings.

The SJE process is particularly effective in straightforward, lower value proceedings. For high value or complex proceedings the SJE process can still work well, but the benefit of potential savings can sometimes be outweighed by the issues - including the risk that the process might fail because one or both of the parties does not agree with the expert’s opinion.

In either case, guidance from an expert who is experienced in SJE processes can help you to assess the issues and decide on the right approach.

This article appeared in Volume 16 Issue 4 of The Family Advocate.


[2] As addressed by the Court of Appeal in Daniels v Walker [2000] 1 WLR 1382