A surveyor who lets an AI tool draft the reasoning in a defects report may soon have to say so, in a formal declaration, before a judge reads a word of the opinion. That is the effect of Recommendation Nine of the Civil Justice Council's final report, Use of AI for Preparing Court Documents, published on 29 October 2026 under the chairmanship of Sir Colin Birss [1]. The proposed expert witness AI declaration under CPR Part 35 would sit alongside the existing statement of truth and would apply wherever AI has generated or influenced the substantive content of an expert's report. One month later, on 30 November 2026, the RICS fifth edition of Surveyors acting as expert witnesses takes effect with its own AI disclosure duties [2]. Together they mark the moment AI use stopped being a private matter for the expert and became a question for the court.
This article explains what the CJC recommended, how it interacts with the RICS standard, and what surveyors giving evidence in building defect, valuation, party wall and boundary disputes should do now.
The CJC working group took a risk-based approach. Instead of regulating by tool category, it asked whether a particular use of AI generates or influences the substantive content of a document put before the court [3]. For lawyers' pleadings and submissions, the answer was that no general duty to declare AI use should be introduced, provided a named professional remains responsible for accuracy [3].
Experts are treated differently. Recommendation Nine states that the CPR should be amended to introduce a requirement for a new, specific declaration concerning AI use where that use generates or influences the substantive content of the expert's report. Where made, the declaration should provide sufficient information to allow scrutiny, which may include disclosing the AI tool to the opposing party and the court so they can assess the methodology, whether AI suited the task, and the substance of the report [1].
Recommendation Ten asks the separate CJC working party revising the 2014 Guidance for the Instruction of Experts in Civil Claims to introduce good practice guidance on AI use by experts [1].
The report also sets out a three-question test that the revised guidance is expected to adopt [1]:
| Question | Why it matters to a surveyor |
|---|---|
| Did AI affect the substance of the evidence? | Transcription, formatting and spell-checking do not trigger the declaration; AI-drafted analysis of a damp survey does |
| What information must be disclosed for scrutiny? | Enough for the other side to test the method, which may mean prompts, inputs and outputs |
| Must the tool itself be named? | Likely where the tool shaped the opinion, so that its reliability can be examined |
The working group considered whether the existing statement of truth under Practice Direction 35, paragraph 3.3, and the duty to disclose methodology [4] already covered the point. It concluded that a separate, distinct AI-specific obligation was preferable to highlight its importance [1].
"The CPR should be amended to introduce a requirement for a new, specific declaration concerning AI use." Civil Justice Council, Recommendation Nine [1]
For chartered surveyors the CJC proposal does not arrive in a vacuum. RICS published the fifth edition of Surveyors acting as expert witnesses in July 2026, with an effective date of 30 November 2026 [2]. It replaces the 2014 fourth edition and converts a UK practice statement into a global professional standard that separates mandatory "must" requirements from "should" guidance [5].
On AI the fifth edition is already ahead of the court rules. Commentary on the standard summarises the position as follows [5]:
The fifth edition also tightens the rules on conflicts of interest. Conflicts must be disclosed in the report itself, significant financial dependence on a repeat instructing party must be declared, and misleading a tribunal can occur through silence, omission or an incomplete answer, not just a false statement [5].
The practical result is that a RICS member who gives expert evidence after 30 November 2026 will already be under a professional duty to disclose AI involvement. If the Civil Procedure Rule Committee adopts Recommendation Nine, that professional duty will be mirrored by a procedural one, with the court's own sanctions behind it.
Defect claims in the Technology and Construction Court turn on causation, scope of remedial works and cost. AI tools are increasingly used to summarise site records, draft schedules of defects and model repair costs. Under the CJC proposal, a surveyor whose report relied on an AI-generated analysis of moisture readings or an AI-drafted remedial schedule would need to declare it and be ready to explain the tool's method under cross-examination [1][3].
Retrospective and Red Book valuations for professional negligence, matrimonial and tax disputes depend on comparable evidence and adjustment. An AI tool that selected or weighted comparables has influenced the substance of the opinion. The valuer would need to declare that and show that the comparables were independently verified.
Party wall surveyors preparing evidence for County Court appeals under section 10(17) of the Party Wall etc. Act 1996, and boundary surveyors giving evidence on the position of a legal boundary, often rely on plan overlays and measurement software. Automated measurement is unlikely to trigger the declaration. An AI-drafted interpretation of the conveyance plan would.
Where the court appoints a single joint expert under CPR 35.7, both parties rely on one report. An undisclosed AI contribution to that report risks the whole exercise being undermined. The CJC's emphasis on sufficient disclosure for scrutiny applies with particular force to single joint experts, who have no opposing expert to test their work.
The CJC did not recommend a new sanctions regime. Instead it proposed a Practice Direction consolidating the existing case law on the court's expectations, so that experts and lawyers can see in one place what happens when AI is misused [3]. The consequences already available include adverse costs orders, referral to professional regulators and, in serious cases, contempt proceedings [3].
The report also recommended that witnesses of fact declare whether AI was used in preparing their statements and confirm that it did not generate or influence the substantive content, which would also require a CPR amendment [3]. Translations must still be certified by a human translator even where AI produced a first draft [3].
Taken together with the fifth edition of the RICS standard and the guidance in the TCC Guide 2026, the direction is clear. Courts are not banning AI. They are insisting that its use be visible, explained and owned by the expert whose name is on the report.
No. The Civil Justice Council's report of 29 October 2026 makes recommendations. The Civil Procedure Rule Committee must decide whether to amend the rules, and no timetable has been published [1][3].
Under the CJC's approach, no. The declaration is triggered only where AI generates or influences the substantive content of the report, not administrative uses such as transcription [1].
From 30 November 2026, RICS members acting as expert witnesses must disclose in writing before accepting an appointment any part of the work to be done by another person or process, including AI, and identify it in the report [2][5].
Yes. Existing powers include adverse costs orders, criticism in judgment, referral to a professional body and, in serious cases, contempt. The CJC proposes a Practice Direction to consolidate those principles [3].
The Civil Justice Council's 29 October 2026 report moves the expert witness AI declaration under CPR Part 35 from good practice to proposed procedural rule. For surveyors the change is compounded by the RICS fifth edition, which imposes its own AI disclosure duties from 30 November 2026. Experts in defects, valuation, party wall and boundary disputes should audit how they use AI, prepare disclosure wording now, and keep records that will survive scrutiny. Solicitors should ask the question at the point of instruction. The expert's opinion must remain the expert's own, and from this winter the court will expect to be told when it is not.
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