Expert Witness Survey 2026: 555 Experts on AI, Late Payment and Independence, and What Instructing Solicitors Should Now Ask Their Surveyor Expert (November 2026)

More than one-third of expert witnesses now use artificial intelligence in their work, yet over 70% want that use disclosed. Both findings come from the Bond Solon Expert Witness Survey 2026, published this month with the Law Society Gazette after fieldwork between 2 and 25 September 2026 [1]. It gathered the views of 555 expert witnesses across medical and non-medical disciplines, in the same month that a senior High Court judge, the Civil Justice Council and RICS have all set firmer expectations on AI, independence and fees.

For solicitors, barristers and insurers who instruct surveyor expert witnesses in building, valuation, party wall and boundary disputes, the questions asked at the point of instruction need to change. This article sets out what the survey found, what judges and regulators now expect, and ten questions to put to any surveyor before instruction.

Key Takeaways

• Over 70% of the 555 experts surveyed back disclosure of AI involvement in report preparation; more than one-third already use AI regularly or occasionally [1].
• The top AI concern is over-reliance at the expense of professional judgement, then inaccuracies and bias. Few think current regulation is sufficient [1].
• Late payment is a significant commercial concern, and many experts want alternative payment arrangements and fee structures [1].
• The RICS 5th edition takes effect on 30 November 2026 and requires disclosure of AI use and of regular reliance on one instructing party [2][3].
• Instructing solicitors should ask about AI policy, income dependence, fee basis, CPR Part 35 experience and insurance before appointing a surveyor expert.

What the Expert Witness Survey 2026 Says About AI

More than one-third of respondents use AI regularly or occasionally, mainly for research, administration, document summarisation and report checking rather than drafting substantive opinion [1].

Experts remain cautious. Their top concern was over-reliance on AI at the expense of professional judgement, followed by AI-generated inaccuracies and bias. Only a small minority felt current regulation and guidance was sufficient [1].

What judges are now saying

Speaking at the Bond Solon Expert Witness Conference at Church House, Westminster, in November 2026, Mrs Justice Joanna Smith, co-chair of the Civil Justice Council working group on AI, told experts to be transparent about any AI use that "may directly or even indirectly generate or influence the content of your evidence" [4]. She identified the core risk as "the erosion of independent judgment, the outsourcing of your opinions to an AI agent", and said that "AI is not an expert and should not be a substitute for expert opinion" [5]. Experts should tell their solicitor early about any intended AI use [4][5].

The Civil Justice Council's final report, "Use of AI for the Preparation of Court Documents" (October 2026), recommends that experts make a declaration where AI has generated or influenced the substantive content of a report, with enough detail to allow the methodology to be scrutinised. These are recommendations for the Civil Procedure Rule Committee to consider, not yet rules [6].

In Cornwall Council v M (2026, EWFC 306), an expert's undisclosed and extensive use of AI, including errors, led the court to give her evidence little weight [6].

Late Payment, Fee Structures and Independence

The second theme of the expert witness survey 2026 is money. Payment delays are a significant commercial concern, and many respondents want alternative payment arrangements and fee structures [1].

This is not only a commercial issue. An expert owed substantial fees by one firm, or dependent on one client for a large share of income, faces obvious pressure on independence. The overriding duty under CPR Part 35, rule 35.3, is to the court rather than the paying party [7]. Agreeing a fee basis and payment schedule in writing at the outset removes a source of later dispute and a line of cross-examination.

What the RICS 5th Edition Requires From 30 November 2026

RICS published the 5th edition of "Surveyors acting as expert witnesses" in July 2026, effective from 30 November 2026 [2]. It binds every RICS member giving expert evidence. The key changes are [2][3]:

• AI disclosure: any use of AI must be disclosed, and AI-derived material treated with the caution given to hearsay.
• Income dependence: experts must disclose regular reliance on the same instructing party, especially where it provides a large share of their income.
• Conditional fees: the general ban on conditional or success fees is kept, with only a narrow exception for pre-existing arrangements meeting four conditions.
• Dual roles: acting as both expert and advocate is discouraged by default.
• Report content: reports must list assumptions, alternative conclusions and third-party contributions.

The consequences of poor practice are spelled out: tribunal criticism, adverse costs, contempt proceedings, negligence claims and RICS disciplinary action [2][3]. A surveyor who cannot explain how their report complies is a risk to the instructing party.

Ten Questions to Ask a Surveyor Expert Witness Before Instructing Them

The expert witness survey 2026 and the new RICS standard point to a clear checklist.

1. What is your AI policy, and how will you declare any AI use? Expect a clear account of tools, tasks and how disclosure will appear in the report [2][6].
2. Do you have any conflicts, and how much of your income comes from this firm or client? Regular reliance on one instructing party must now be disclosed [2][3].
3. What is your fee basis? Confirm hourly or fixed fees, payment terms and that no conditional or success fee element is involved [2].
4. How much CPR Part 35 experience do you have? Ask about reports written and familiarity with rule 35.3 and Practice Direction 35 [7].
5. Have you acted as a single joint expert? Rule 35.7 experience shows an ability to serve both parties fairly [7].
6. What methodology will the report follow? Assumptions, alternative conclusions and third-party contributions must be listed [2][3].
7. Will you inspect the site and carry out testing? Desk-based opinions on defects or boundaries rarely stand up.
8. How do you approach joint statements with the other expert? A cooperative method narrows the issues.
9. What are your timescales? Confirm availability for inspection, report, joint statement and trial dates.
10. What professional indemnity insurance do you hold? Confirm the level of cover and that expert witness work is included.

Networks such as Survey Merchant, which connect instructing parties with RICS surveyors offering building surveys, valuations and expert witness services, can help match a dispute to a surveyor already working to the 5th edition.

When a Single Joint Expert Suits Property Disputes

The single joint expert route under rule 35.7 is often the most proportionate option in property cases [7]. It can suit:

• Building disputes where one inspection can settle whether work is defective and what remedy is needed.
• Valuation disputes where the parties need a single independent figure for settlement, division or sale.
• Party wall matters where a neutral opinion on damage or works can resolve the point.
• Boundary disputes where the boundary turns on plans, physical features and measurement rather than contested judgement.

It is less suitable where the technical issues are genuinely contested, where the sums at stake justify two experts, or where a party needs an adviser as well as a court expert. Any earlier building survey for one party should be disclosed before a joint appointment.

Frequently Asked Questions

Who ran the expert witness survey 2026 and how many people took part?

Bond Solon ran it with the Law Society Gazette. Fieldwork ran from 2 to 25 September 2026, 555 expert witnesses responded, and results were published in November 2026 [1].

Do surveyor expert witnesses have to disclose AI use?

Yes, from 30 November 2026 under the RICS 5th edition [2][3]. The CJC has also recommended a formal declaration where AI has influenced substantive content, though that is not yet a rule [6].

Can a surveyor expert witness act on a no-win, no-fee basis?

In general, no. The RICS 5th edition keeps the ban on conditional and success fees, with only a narrow exception for pre-existing arrangements that satisfy four conditions [2][3].

What happens if an expert's AI use is not disclosed?

In Cornwall Council v M (2026, EWFC 306), undisclosed AI use that included errors led the court to give the expert's evidence little weight [6]. Under the RICS standard, poor practice can also lead to adverse costs, negligence claims and disciplinary action [2][3].

Why does late payment matter for independence?

The survey found payment delays to be a significant commercial concern [1]. An expert owed large sums by one client faces pressure that sits uneasily with the overriding duty to the court under CPR Part 35 [7].

Conclusion

The expert witness survey 2026 shows a profession adopting AI carefully, worried about its effect on judgement, and frustrated by slow payment. The courts, the Civil Justice Council and RICS have responded with the same themes: transparency about AI, disclosure of financial dependence and firm limits on fees.

The next steps are practical. Update letters of instruction to require a statement of AI use and a declaration of income dependence. Agree fee terms and a payment schedule in writing before work starts. Ask the ten questions above at the first conversation, and consider whether a single joint expert would serve the dispute better. Where a surveyor expert is needed, choose one who already works to the RICS 5th edition.

References

1. Bond Solon, "Expert Witness Survey 2026", November 2026. bondsolon.com.
2. RICS, "Surveyors acting as expert witnesses" (5th edition). rics.org.
3. Rimkus, "RICS 2026 Expert Witness Guidance: Key Changes for Surveyors", August 2026. rimkus.com.
4. The Lawyer Mag, "UK judge instructs expert witnesses to be transparent about AI use", 10 November 2026. thelawyermag.com.
5. Solicitors Journal, "AI should not replace experts' views", 11 November 2026. solicitorsjournal.com.
6. Lewis Silkin, "CJC final report on AI and court documents", 5 November 2026. lewissilkin.com.
7. Ministry of Justice, Civil Procedure Rules Part 35. justice.gov.uk.