RICS Updates Expert Witness Standard After More Than a Decade
The publication of the fifth edition of Surveyors Acting as Expert Witnesses marks the first major refresh of the RICS standard in over ten years. Although the previous edition was updated in 2023, the framework itself had remained largely unchanged since 2014. With expert witness work continuing to evolve alongside litigation practices, technology and international markets, an update had become increasingly necessary.
Published on 30 July 2026, the new standard will come into force on 30 November 2026, giving surveyors and firms a four-month window to review their procedures and ensure compliance.
Perhaps the most notable change is that the standard is no longer focused solely on the UK. The fifth edition has been issued as a global professional standard, applying to RICS members wherever they practise. This reflects the reality that surveyors are increasingly involved in disputes spanning multiple jurisdictions, particularly in the property, construction and valuation sectors.
That said, RICS has been careful not to present the new standard as a substitute for local rules or legislation. Requirements governing expert evidence vary significantly between courts and tribunals around the world, and members are expected to satisfy themselves that their approach remains consistent with the applicable legal framework. Where any inconsistency arises, local law will take precedence.
The revised guidance places greater scrutiny on the decision to accept instructions in the first place. While competence and independence have always been fundamental requirements for expert witnesses, the fifth edition sets out those expectations in greater detail. Surveyors must be satisfied not only that they possess the necessary expertise, but also that they have the resources, availability and practical capacity to complete the assignment properly.
Importantly, the standard reinforces a point that is sometimes overlooked: expertise in surveying does not automatically translate into expertise in every surveying discipline. Members are expected to act only within their own field of competence and should not accept instructions requiring opinions outside that area.
There is also a stronger emphasis on the management of instructions and conflicts of interest. Before accepting an appointment, experts should clearly establish the scope of their engagement and confirm in writing their role, the applicable tribunal rules and their overriding duty to the court or tribunal. The standard further requires experts to keep appropriate records of the matters on which evidence is sought and to identify any third parties, processes or technologies that contribute to the work.
Conflict checking has become an increasingly important issue in expert witness practice, particularly where surveyors may have previously advised one of the parties involved in a dispute. The new edition requires conflicts to be considered at the outset and disclosed promptly should they emerge during the course of an instruction.
The treatment of fees has also received much greater attention. The fifth edition adopts a firmer position on arrangements that may compromise, or appear to compromise, an expert's independence. In most circumstances, experts should not undertake work where their remuneration is linked to the outcome of the proceedings.
The restrictions extend beyond the expert personally and may also affect situations where the wider firm is operating under conditional, deferred or success-based fee arrangements. While RICS has included a limited exception for certain pre-existing arrangements, the conditions attached to that exception are narrow and include disclosure obligations to both the client and, where appropriate, the tribunal.
Unsurprisingly, artificial intelligence features prominently among the changes. For the first time, the standard expressly addresses the use of AI and similar technologies in the preparation of expert evidence.
Rather than prohibiting their use, RICS has focused on transparency and accountability. Experts remain responsible for the opinions expressed in their reports and must disclose where AI, automated processes or third-party assistance have played a role in producing the work. The final report should clearly identify the tools and methodologies used and explain the extent of their contribution.
The accompanying guidance also highlights the potential evidential risks associated with AI-generated material, particularly where questions arise regarding the source, reliability or completeness of the information produced.
Closely linked to this is the requirement that expert evidence must genuinely represent the expert's own judgement. The fifth edition makes clear that reliance on generic templates, pre-prepared schedules or copied material cannot replace independent professional analysis. While support staff, specialist testing and technological tools may all form part of the process, ultimate responsibility for the evidence remains with the appointed expert.
Reporting requirements have also become more detailed. Experts are expected to identify clearly the facts, assumptions and methodologies underpinning their conclusions, as well as any limitations affecting their opinion. Greater transparency is required regarding instructions received, documents considered and any third-party input relied upon.
The new edition also acknowledges that opinions can evolve as further evidence emerges. Where an expert changes their view during proceedings, the reasons for doing so should be explained openly rather than ignored or obscured.
Another area of focus is the distinction between the roles of expert witness and advocate. The longstanding principle that an expert's primary duty is to the tribunal, rather than to the appointing party, remains unchanged. However, the fifth edition goes further in discouraging surveyors from acting as both advocate and expert witness in the same matter.
Although exceptions may exist where permitted by a tribunal, surveyors taking on dual roles are expected to consider carefully the impact on their perceived independence and explain the associated risks to their clients.
Taken as a whole, the fifth edition does not represent a fundamental shift in the duties owed by expert witnesses. Independence, impartiality, competence and integrity remain the cornerstones of expert evidence. What the new standard does provide is greater clarity around how those principles should operate in modern practice.
For many firms, the practical implications are likely to involve reviewing engagement terms, conflict-checking procedures, report templates, fee arrangements and internal policies governing the use of AI. With implementation now only a few months away, those reviews would be well worth undertaking sooner rather than later.
