There are no legal or statutory requirements as to how many commissioners should make decisions (other than the requirement to appoint at least one independent commissioner if requested under section 100A or 357AB). Principles contained in case law, common practice, and overseas examples do, however, provide some guidance.
The number of commissioners should match the scale of the decision that needs to be made, its complexity, and the experience and expertise of the commissioners. Any policies and guidelines drafted to guide councils in using commissioners should reflect this principle.
Single-issue decisions of low complexity will generally require only one commissioner.
Complex decisions, for example applications dealing with technical arguments on many different issues, may require two or more commissioners. One commissioner will often be employed to take into account the overall considerations of the application and guide the conduct of proceedings; the other(s) may consider the more detailed technical evidence according to their knowledge and experience. There should be sufficient expertise in the panel to ensure full understanding of the relevant evidence and information presented.
Applications and plan changes with large numbers of submissions may warrant the use of more than one commissioner: the issues covered by submitters may be varied and require a range and depth of technical knowledge which no single commissioner can be expected to have.
Some councils use an odd number of commissioners in hearings to avoid ‘stalemate’ situations. With an even number of commissioners, councils may want to identify which commissioner's view will prevail or have a casting vote (usually the chairperson or principal commissioner) in the appointment/delegation of powers to commissioners. For most hearings, no more than three commissioners should be needed.