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Expert's duty to the panel

An expert witness has a paramount duty to the panel and not to the person who has engaged them.

An expert witness will assist the panel on matters relevant to their expertise, they are not an advocate for a party to a proceeding.

Expert witness reports

Expert witness reports or statements must be submitted in accordance with directions made at the directions hearing.

If no specific directions are made, reports or statements must be given to the panel coordinator and other parties at least five working days before the hearing. An earlier date will be specified for more complex reports.

Reports should be provided:

  • to the panel: unlocked pdf or Microsoft Word format
  • to the planning authority: pdf suitable to upload to a website

Other people may request copies by contacting the panel coordinator.

Before the hearing, witnesses’ reports or statements will normally be available for viewing at the offices of the planning authority.

Content and form of expert witness reports

An expert witness report must include:

  • the name and address of the expert
  • the expert's qualifications and experience
  • a statement identifying the expert's area of expertise to make the report
  • a statement identifying other contributors to the report and their expertise
  • all instructions that define the scope of the report – original and supplementary and whether in writing or oral
  • identity and qualifications of people that carried out tests or experiments that the expert has relied on.

All electronic material supplied should be unlocked and must be able to be searched and copied.

Expert reports used for the amendment or proposal

If an expert has prepared a report that was used to inform preparation of an amendment or proposal, do not provide a revised version of that report.

Provide a brief report that includes:

  • an unambiguous reference to the report or reports that the expert relies on
  • a statement identifying the role that the expert had in preparing or overseeing the exhibited report/s
  • a statement to the effect that the expert adopts the exhibited report
  • any departure from the finding or opinions expressed in the exhibited report
  • questions falling outside the expert's expertise
  • key assumptions made in preparing the report
  • whether the exhibited report is incomplete or inaccurate in any respect.

Expert reports prepared for the panel

Where a report has not been used to prepare an amendment or proposal, the report should include:

  • the facts, matters and all assumptions that the report relies on
  • reference to documents and other material that the expert has been instructed to consider in preparing the report
  • literature or other material used
  • a summary of the opinion/s of the expert
  • identification of provisional opinions that are not fully researched and the reason they are not fully researched
  • a statement setting out any questions falling outside the expert's expertise
  • whether the report is incomplete or inaccurate in any respect.

The expert must declare at the end of the report:

‘I have made all the inquiries that I believe are desirable and appropriate and no matters of significance which I regard as relevant have to my knowledge been withheld from the panel.’

You must ensure that any expert providing a report for use in the proceeding is aware of the contents of this direction when you ask them to provide evidence.


An expert witness needs to be aware of their obligations in the Information Privacy Act 2000 particularly when using personal information contained in submissions they have received as a third party.

Expert witness reports are generally published on the planning authority’s website.

Where possible, the report should not refer to any submitter by name. If necessary submitters should be referred to by submission number.

Find out more about how we manage privacy.

Change of opinion on a material matter

An expert witness who changes an opinion on a material matter based on another expert's report, or for any other reason, must communicate that change of opinion in writing to be filed with the panel as soon as practicable.

They must specify reasons why their opinion has changed.

Expert witness meetings

Expert witnesses are encouraged to meet to narrow any points of difference between them and to identify any remaining points of difference. The panel may also direct that they meet.

If expert witnesses meet, they must each set out in a document filed with the panel any agreed points and all remaining points of difference.

If any expert witness directed by the panel to meet with any other expert is instructed not to reach agreement in respect of points of difference, the fact of such instructions must be reported in writing to the panel by the expert witness.

Practice Note 1 — Expert evidence

Page last updated: 01/07/24