Aipedia: Quantity surveyors

AI in quantum expert reports: independence and admissibility

Aipedia, by the Apex broking team · Last reviewed 2026-10-30

Quantum experts can use AI to analyse records and help draft reports, but the opinions must be their own and every point must be verified. An expert's overriding duty is to the court, and a report shaped by unverified AI output risks criticism or exclusion.

Part of: AI in quantity surveying

In short

Quantum experts are using AI to sort and analyse large volumes of cost records and to help draft reports. RICS Modus reported in November 2025 that 20% of surveyed expert witnesses had used AI, and RICS says AI must not replace the expert's own knowledge and judgement. Chartered surveyor experts must have regard to the RICS professional statement on surveyors acting as expert witnesses, and CPR 35.3 makes the expert's duty to the court override duties to the client. Fictitious citations or unverified analysis can damage the report and the expert. Expert work usually needs specific PI attention.

How quantum experts use AI

A quantum expert in construction disputes may have to review tens of thousands of documents: accounts, invoices, timesheets, valuations and correspondence. AI tools can classify these, extract figures, reconcile costs to records and draft sections of the report. Generative AI chatbots are also used to tidy language and structure.

RICS Modus (24 November 2025) reported that 20% of surveyed expert witnesses had used AI, and that 89% want specific UK guidance on its use. RICS says AI can improve language and format but must not replace the expert's own knowledge and judgement. The general surveyor angle is covered at AI in surveyor expert witness reports.

The duties that apply

The relevant duties are:

CPR Part 35: under CPR 35.3, it is the duty of experts to help the court on matters within their expertise, and this duty overrides any obligation to the person instructing or paying them.
RICS professional statement: chartered surveyor experts must have regard to Surveyors acting as expert witnesses.
RICS AI standard 4.2: the expert, as a named surveyor, makes a written reliability decision on AI outputs, with dip sampling of automated analysis.
3.1: disclosure documents are confidential; get express prior written consent before uploading them, and check any court or tribunal restrictions on their use.
4.3 and 4.4: tell instructing parties in advance that AI is used and explain the system if asked.

What can go wrong

Typical failure points include:

Loss of independence: the AI drafts from the instructing party's pleadings, and the report adopts their framing without the expert noticing.
Unverified analysis: cost reconciliations produced by AI are presented as the expert's own work without being checked.
Fictitious references: in Ayinde [2025] EWHC 1383 (Admin), the Divisional Court addressed fictitious AI-generated citations; RICS has highlighted the case to expert witnesses.
Cross-examination: the expert cannot explain how a figure was produced.

Illustrative: a quantum expert uses AI to reconcile a contractor's prolongation costs and draft the report. In cross-examination, opposing counsel shows that a key table cannot be traced to the disclosed records and that the methodology section repeats the claimant's own pleaded case. The judge gives the report little weight. The instructing client loses part of its claim and alleges the expert was negligent.

How PI usually responds

A flawed report may lead to criticism from the court, regulatory scrutiny or a claim by the instructing client. Where a client claims, it is usually handled as professional negligence under the RICS Approved Minimum Wording, subject to the policy terms, provided expert work is within the declared business. Some firms buy specific cover or extensions for expert witness work. See expert witness insurance and construction claims and expert witness PI.

Practical controls

You can reduce the risk with these steps:

Form your own opinion before using AI to draft the narrative.
Trace every figure in the report to a disclosed record.
Verify every authority and standard referred to.
Be ready to explain in evidence how AI was used and how outputs were checked.
Keep working papers that show the checks performed.
Run AI analysis on a copy of the disclosed documents in a tool that does not retain or train on the data.
Declare expert work to your insurer and confirm cover.

How Apex helps

Apex arranges PI for quantity surveyors who act as quantum experts, and a broker can check that expert work is declared and covered. Related: AI-drafted adjudication submissions, AI loss and expense claims and the QS AI hub.

Sources

Frequently asked

Can a quantum expert use AI at all?

Yes. RICS says AI can help with language and format but must not replace the expert's own knowledge and judgement. The expert must be able to stand behind every opinion and figure, and should be ready to explain how AI was used.

Do I need to tell the court I used AI?

Under the RICS AI standard you must tell your client in writing in advance. Also check the court's directions and the RICS expert witness professional statement. Being open about methodology supports the expert's duty to help the court, and you may be asked about it in cross-examination.

Is expert witness work covered by QS PI?

It depends on the policy and what you declared. QS policies may include it, but some insurers may treat expert work as a separate activity needing specific disclosure. Check with your broker before accepting instructions.

How can AI threaten an expert's independence?

If the tool is fed the instructing party's pleadings and asked to draft, it may adopt that party's framing and conclusions. Under CPR 35.3 the expert's duty to the court overrides duties to the client, so form your own view from the records first and use AI only to support it.

Check your PI covers how you use AI

Tell us about your firm and the work you do. A broker will review how your current PI treats AI-assisted work, or arrange new cover. No fee for a quote. Or call 0117 325 0027.

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Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales, company number 07014570. This page is general information about how AI is used in the profession and how insurance may respond. It is not legal, regulatory or insurance advice on your circumstances, and it does not guarantee that cover will be available or on what terms.