RICS Launches the Fifth Edition of Surveyors Acting as Expert Witnesses: What Has Changed and Why It Matters

July 31, 2026

RICS has published the fifth edition of its professional standard, Surveyors acting as expert witnesses, accompanied by a separate practice guidance document, Additional guidance for surveyors acting as expert witnesses.

The new edition represents the first major revision of the standard since the fourth edition was published in 2014. It has been developed to reflect changes in professional practice, tribunal procedure, technology and the increasing scrutiny placed upon expert evidence.

Importantly, the fifth edition does not take effect immediately. It becomes effective on 30 November 2026. Until then, the fourth edition remains the applicable RICS practice statement and guidance note for RICS members acting as expert witnesses. The intervening period provides experts, instructing solicitors and regulated firms with an opportunity to review their procedures, terms of engagement and report templates before the new requirements become mandatory.

The revision is more than a reformatting exercise. Although the fundamental duties of an expert witness remain unchanged, the fifth edition introduces greater precision and transparency in relation to:

the scope and application of the standard;
conflicts of interest and financial dependence;
the acceptance and continuing review of instructions;
fees and fee estimates;
the involvement of assistants and the use of artificial intelligence;
the preparation and amendment of expert reports;
expert meetings and joint statements;
oral evidence; and
the distinction between expert evidence, advice, advocacy and case management.

For those who instruct experts in construction disputes, particularly on questions of quantum and professional negligence, the changes provide a useful framework against which the suitability, independence and quality of an expert can be assessed.

The continuing foundation: the expert’s duty is to the tribunal

The central principle has not changed.

An expert witness is not retained to win the case for the party instructing them. Their primary and overriding duty is to assist the court, adjudicator, arbitrator or other tribunal by providing truthful, impartial and independent opinion evidence.

The fourth edition already required expert evidence to be the independent and unbiased product of the expert, to identify the facts and assumptions upon which it was based and to remain uninfluenced by those instructing or paying the expert. It also required experts to address relevant matters even where they did not support the client’s case.

The fifth edition retains that foundation but expresses it in more direct and comprehensive terms. It specifically states that misleading a tribunal may occur not only through an expressly incorrect statement, but also through:

silence;
omission;
failure to correct;
implication; or
an incomplete answer.

That is an important clarification. Independence is not satisfied merely by avoiding an untrue statement. An expert must ensure that the overall impression given by their evidence is complete, balanced and accurate.

This is particularly relevant in quantum and professional negligence cases. A quantum expert cannot simply identify the calculations that support the instructing party’s valuation while ignoring records or valuation principles that point in another direction. Equally, an expert considering the performance of an employer’s agent, quantity surveyor, contract administrator or project manager must address both the alleged failures and the contractual, factual and professional context in which the services were performed.

An independent expert may ultimately support the client’s case, reject part of it or reach a materially different conclusion. That is not a defect in the expert process. It is the very safeguard that gives expert evidence its value.

From a UK practice statement to a global professional standard

One of the clearest structural changes is the status and reach of the document.

The fourth edition is described as an RICS practice statement and guidance note applying principally within the UK. Its mandatory provisions are contained within the practice statement, with recommended good practice contained in the accompanying guidance note.

The fifth edition is a global RICS professional standard. It separates:

mandatory professional requirements, expressed through the word “must”; and
expected professional practice, generally expressed through the word “should”, in the accompanying guidance.

The fifth edition applies globally, although local legislation and procedural rules take precedence where they conflict with the RICS requirements. It also adopts a deliberately wide definition of “tribunal”, extending beyond conventional court proceedings to include arbitration, construction adjudication, dispute boards, independent expert determination, early neutral evaluation and other decision-making processes.

This is particularly significant in construction disputes. Expert evidence is frequently used in statutory and contractual adjudication, sometimes under extremely compressed timetables. The fifth edition makes it clear that the temporary or permanently binding nature of the decision does not determine whether the standard applies. Where an RICS member acts or purports to act as an expert witness, the professional obligations apply.

The standard also applies throughout the duration of the appointment. It is not limited to the final report or the giving of evidence at a hearing.

Greater clarity between the different professional roles

The fifth edition gives much greater emphasis to identifying the capacity in which a surveyor is acting.

A surveyor involved in a dispute may act as:

an adviser;
a witness of fact;
an expert witness;
a negotiator;
a case manager; or
in limited circumstances, a surveyor-advocate.

These roles are not interchangeable.

An adviser is retained to advance the interests of the client by providing professional advice. An expert witness has an overriding duty to the tribunal. A witness of fact describes what they saw, did or experienced. A surveyor-advocate presents the client’s properly arguable case.

In practice, difficulty can arise where an individual who has advised a party, prepared the claim, conducted negotiations or managed the dispute is subsequently asked to act as the independent expert. Prior involvement does not necessarily create an absolute prohibition, but it can create an actual or perceived conflict and may reduce the weight attached to the evidence.

The fifth edition requires members acting as case managers as well as expert witnesses to disclose the case-management role clearly to the tribunal. It also reinforces the prohibition on giving legal advice. Surveyors may explain technical and procedural matters within their competence, but should direct clients to suitably qualified lawyers for legal advice.

This is an important distinction in professional negligence cases. An expert may be asked to provide an opinion on the standard reasonably expected of a surveying professional and whether the work in question fell below that standard. The expert should not purport to determine the ultimate legal issue of negligence. That remains a matter for the tribunal.

Similarly, a quantum expert may give an opinion on valuation, loss and cost consequences, but should not stray into deciding disputed issues of contractual interpretation unless expressly asked to consider alternative assumptions.

A more rigorous approach to competence and instructions

The fourth edition required experts to possess the relevant experience, knowledge, expertise and resources before accepting an appointment.

The fifth edition expands this into four express requirements. An expert must have:

the ability to act impartially;
the ability to act competently;
the appropriate experience, knowledge and expertise; and
sufficient resources to complete the work within the required timescale and standard.

Competence is therefore not established merely by possessing a professional qualification. The proposed expert must have the particular experience needed for the issues in dispute.

That distinction is highly relevant when choosing a construction expert. A chartered surveyor may be experienced in measurement or general commercial management without necessarily having the experience required to analyse a complex termination account, assess prolongation loss or address the duties of an Employer’s Agent under a design and build contract.

Before accepting instructions, the fifth edition requires the expert to investigate and verify them. The expert must confirm in writing:

the nature of the expert witness role;
that the RICS standard and applicable tribunal rules will apply;
that the overriding duty is owed to the tribunal; and
where relevant, that the regulated firm’s ordinary complaints-handling procedure will not apply to the expert witness engagement.

There must be a written record of the matters upon which expert evidence is required. Instructions must then be reviewed throughout the appointment rather than treated as a static document.

Where the scope changes, new issues emerge or the expert requires assistance from another person, the position must be recorded and communicated.

The fifth edition therefore encourages better discipline at the start of an appointment.

Properly framed instructions should identify:

the tribunal and applicable procedural rules;
the issues requiring expert opinion;
the relevant factual assumptions;
the documents to be considered;
the required outputs;
the timetable;
any meetings or joint statements; and
the limits of the expert’s role.

A clear instruction is not simply an administrative matter. It reduces the risk of duplication, scope drift, avoidable cost and an expert inadvertently giving evidence outside their competence.

Conflicts of interest: a continuing and more demanding obligation

The fourth edition already required experts to carry out conflict checks, disclose actual or potential conflicts and consider whether previous involvement might compromise their independence.

The fifth edition strengthens that obligation in several ways.

Members must remain continuously astute to conflicts throughout the appointment. Conflicts must be disclosed in the expert report itself, rather than being treated solely as a private matter between the expert and the instructing party.

The standard also expressly addresses repeated instructions and financial dependence. Where an expert regularly receives work from the same instructing party and derives a significant proportion of their income from that source, the financial relationship must be disclosed so that the tribunal and the parties can assess its relevance. This is a notable development.

Repeat instructions do not automatically mean that an expert lacks independence. Many established experts are regularly instructed by the same solicitors, insurers, employers or contractors because of their specialist experience. However, the new standard recognises that independence must not only exist; it must also be capable of being evaluated by others.

In practice, experts and their firms should now review whether their conflict-checking procedures capture:

current and previous work for the parties;
involvement with the project or property;
relationships with the solicitors or other experts;
financial or commercial interests;
work for associated companies;
repeat instructions from a particular source; and
any significant reliance upon that source for fee income.

The obligation continues after appointment. A newly discovered conflict must be disclosed immediately, with the expert considering whether the cause can be removed, whether withdrawal is required or whether directions should be sought from the tribunal.

Fees and fee estimates

The treatment of fees is another area in which the fifth edition provides more detailed requirements.

The expert must confirm in writing:

the scope of the appointment;
the basis upon which fees and expenses will be charged; and
responsibility for payment.

Where a fee estimate is requested, it must only be provided once the expert has obtained a proper understanding of both the case and the scope of the appointment.

That is a practical and important requirement. Expert appointments are frequently costed before the expert has received the material necessary to understand:

the volume of documentation;
the number and complexity of the issues;
the quality of the underlying records;
the number of reports required;
whether inspections are necessary;
whether meetings and joint statements are anticipated; and
whether oral evidence is likely.

An unrealistically low estimate may be attractive at the appointment stage but can create difficulties later. Conversely, a properly explained estimate, divided into stages and assumptions, gives the client and legal team a meaningful basis for budgeting and cost management.

For complex quantum and professional negligence instructions, sensible fee arrangements may identify separate allowances for:

initial review and preliminary advice;
detailed document analysis;
inspection and investigation;
preparation of the principal report;
consideration of the opposing expert’s report;
written questions;
expert meetings and joint statements;
conferences with counsel or the legal team;
mediation or settlement meetings; and
preparation for and attendance at the hearing.

The expert should also make clear that an estimate is not necessarily a fixed fee and should identify the assumptions upon which it is based.

Conditional and deferred fees

The fourth edition adopted a firm position that an expert should not undertake an appointment under any conditional or success-based arrangement, including where those instructing the expert were themselves working under such an arrangement.

The fifth edition retains the general prohibition but introduces a carefully defined exception.

An expert may only act where a conditional or deferred fee arrangement exists in exceptional circumstances and where all the prescribed conditions are satisfied. These include:

the tribunal’s rules and practice must permit the arrangement;
the arrangement must arise from a pre-existing relationship rather than a new agreement created for the expert evidence;
the client must be told that the arrangement may affect the weight attached to the evidence and must consent to the appointment; and
the arrangement must be disclosed to the tribunal where required.

A prescribed declaration must also be included in the report.

The exception should not be misunderstood as a general relaxation. The starting position remains that expert remuneration must not depend upon the result of the case or the nature of the evidence given. Any financial structure that rewards a particular opinion or outcome is fundamentally difficult to reconcile with independent expert evidence.

Artificial intelligence, assistants and work undertaken by others

The fourth edition contemplated reliance upon examinations, measurements, tests, experiments and surveys carried out by others. It required the report to identify the person involved, their qualifications and methodology, the extent of the expert’s supervision and any implications for the evidence.

The fifth edition retains those principles but expressly extends them to artificial intelligence and other decision-making or analytical tools.

Where any part of the assignment is to be undertaken by another person or through a different process, including artificial intelligence, this must be disclosed in writing before the appointment is accepted and identified unequivocally in the completed report.

Expert evidence must remain the expert’s own work, save where work is carried out at the expert’s direction and under their supervision.

The standard also treats AI-generated material as potentially falling within the concept of hearsay and requires experts to identify the tools and methodology used. Sources, professional literature, technological devices and analytical processes relied upon must be referenced appropriately.

This does not prohibit responsible use of technology. Digital measurement, document-analysis software, programming, databases and AI-assisted processes can all improve efficiency. However, the expert remains personally responsible for:

verifying the source material;
understanding the method;
checking the output;
identifying limitations;
protecting confidential information;
avoiding fabricated or unreliable references; and
ensuring that the final opinion is genuinely their own.

An expert cannot delegate professional judgment to a software product and then sign the resulting report as though it were entirely their independent work.

For quantum experts, this is particularly relevant where large datasets, cost ledgers, valuations, programme information or document populations are analysed electronically. The methodology should be transparent and reproducible, and the expert must understand how the results were produced.

Research, documents and inspections

The fourth edition required an inspection where one was necessary to produce a professionally competent opinion and, if an inspection was not undertaken or was inadequate, required that limitation to be explained.

The fifth edition preserves that duty but introduces the express concept of proportionality. An inspection must be appropriate having regard to:

its purpose;
the practicalities;
the circumstances of the case; and
the need to provide a professionally competent opinion.

The standard also requires experts to carry out the factual research they consider necessary and to make efforts to obtain the documents and information required to form their opinion properly.

This matters because an expert should not simply accept the document selection made by the instructing party without considering whether important material may be missing.

In a quantum dispute, the expert may need access to the contract, variations, payment records, cost reports, labour records, procurement documentation, correspondence, programmes and contemporaneous commercial records.

In a professional negligence claim, the necessary material may extend to the professional appointment, scope of services, project records, advice, reports, valuations, certificates, meeting minutes, correspondence, applicable standards and the information available to the professional at the relevant time.

Where important records have not been provided, the expert should ask for them. If they remain unavailable, the report must identify the limitation and explain its effect upon the opinion.

More demanding requirements for written reports

The fifth edition builds upon the detailed reporting requirements already contained in the fourth edition.

Reports must continue to state the expert’s qualifications and relevant experience, identify material instructions, distinguish fact from opinion, explain assumptions and limitations, address competing opinions and include a summary of conclusions.

The fifth edition adds or strengthens several requirements.

The report must be the expert’s own

Experts must not use pre-populated templates, standard schedules of charges or copy-and-paste reports prepared by third parties.

This is not a prohibition on having a consistent house style or report structure. The concern is with material being inserted without the expert’s independent analysis.

Every report must reflect the particular facts, evidence, issues and instructions of the case.

Reasoning must be fully explained

The fifth edition requires experts to “fully and properly rehearse” the reasoning supporting their opinions.

A conclusion is not made persuasive simply by being expressed firmly. The tribunal must be able to understand:

what information was considered;
what principles were applied;
how the evidence was evaluated;
which assumptions were made;
what alternatives were considered; and
why the expert reached the stated conclusion.

This is especially important in professional negligence evidence. Merely stating that a professional “failed to exercise reasonable skill and care” is not enough. The report should identify the relevant duty or accepted practice, explain the conduct reasonably expected, analyse what was actually done and provide a reasoned opinion on the alleged departure.

Likewise, a quantum report must do more than reproduce a spreadsheet. It should explain the valuation methodology, contractual basis, source records, adjustments, assumptions and treatment of contested items.

Alternative legal or contractual assumptions

Where conclusions depend upon an assumed interpretation of legislation, contractual wording or case law, the expert must identify that assumption and provide alternative conclusions based on the opposite assumption where appropriate.

This is a particularly useful requirement.

Experts should not decide disputed questions of law. By presenting alternative calculations or technical opinions, they can assist the tribunal regardless of the legal conclusion ultimately reached.

For example, a quantum expert might provide one valuation on the basis that a particular instruction constituted a compensable variation and another on the basis that it did not. That is generally more useful than the expert purporting to decide the contractual issue.

No fact-finding disguised as opinion

Where material facts are disputed, the expert must provide an opinion on each relevant factual hypothesis. The expert should not make findings of fact or express a preference unless expert knowledge enables them to demonstrate that one factual account is improbable or less probable.

This reinforces the proper division of responsibility. The tribunal finds the facts; the expert explains the professional or technical consequences of the competing factual cases.

Expanded declarations

The fifth edition introduces revised declarations at the end of the report. These include confirmation that:

all material facts affecting the opinion have been identified;
the expert understands and has complied with the overriding duty to the tribunal;
there is no prohibited conditional fee arrangement;
there are no conflicts other than those disclosed;
the applicable tribunal requirements have been followed;
the report complies with the edition of the RICS standard current when it was drafted; and
the expert will notify those instructing if circumstances change before the hearing.

Experts and instructing solicitors should therefore ensure that report templates are updated in good time before 30 November 2026.

Amendment of reports and interference with expert evidence

Both editions recognise that an expert may change their opinion when new information becomes available. That is not inherently a weakness. A properly reasoned change of view may demonstrate independence and professional integrity. The fifth edition nevertheless imposes clearer obligations.

Where a material inaccuracy, omission or change of opinion arises following disclosure, the expert must give written notice without delay, with reasons, to those instructing and, where appropriate, the tribunal.

The expert must reject any proposed amendment that does not accord with, or would distort, their true independent opinion.

The new standard also addresses unauthorised alteration more directly. Where an expert becomes aware that their report has been changed, they must require the alteration to be corrected. If it is not corrected, the expert may need to report the person or organisation responsible to the relevant regulator, cease accepting instructions from them and notify the tribunal where the report has already been submitted.

This sends an appropriately strong message: the expert’s report belongs intellectually and professionally to the expert. Lawyers and clients may identify errors, request clarification and test the reasoning, but they must not rewrite the opinion to improve the case.

Earlier expert engagement and narrowing the issues

The fourth edition encouraged experts to communicate, identify agreed and disputed matters and consider whether differences could be narrowed.

The fifth edition places greater emphasis on early engagement. Experts must raise with those instructing the potential advantages and disadvantages of:

early communication with the opposing expert;
identifying the actual issues in dispute;
understanding the reasons for differences of opinion; and
producing a statement of agreed and disputed matters.

Before an expert discussion begins, the experts must agree whether it is being conducted on a without-prejudice basis.

The accompanying guidance suggests that expert discussions can be valuable before positions become entrenched and even at the draft-report stage. Properly conducted meetings may lead to shorter reports, reduced costs and a clearer focus for the tribunal.

This has obvious relevance to construction disputes, where lengthy schedules can sometimes conceal that the experts agree on the majority of the underlying principles and differ only on a limited number of assumptions, quantities or valuation judgments.

Experts must remain independent during those discussions. They cannot be directed by the client or legal team as to the opinions they should express. If a settlement opportunity becomes apparent, the expert should report it to those instructing but should not assume the role of negotiator unless separately and appropriately instructed.

Oral evidence and continuing responsibility

The fifth edition includes more detailed requirements for oral evidence.

Where evidence is given orally without a written report, the expert must first make declarations confirming:

that evidence will be confined to their area of expertise;
that their overriding duty is owed to the tribunal; and
that the evidence will comply with the applicable tribunal rules and RICS standard.

Answers must be full, clear and properly contextualised. If the expert changes their opinion during or after giving evidence, both the instructing party and the tribunal must be informed.

The accompanying guidance also addresses concurrent expert evidence, often called “hot-tubbing”, and reminds experts that evidence should be directed to the tribunal rather than treated as an argument with the advocate or opposing expert.

The dual role of expert and advocate

The fourth edition permitted a dual role in limited circumstances, particularly where tribunal practice allowed it and the costs of retaining separate individuals would be disproportionate.

The fifth edition adopts a more emphatic starting point: members must not act as both surveyor-advocate and expert witness except in the limited circumstances expressly permitted.

Before accepting a dual appointment, the surveyor must consider whether it is both permissible and appropriate and must explain to the client:

the possible effect upon actual or perceived impartiality;
the possible effect upon advocacy;
whether both roles can be fulfilled with professional integrity; and
whether appointing separate people would be more appropriate.

The dual role must be disclosed to the tribunal and clearly distinguished throughout the proceedings.

For construction adjudication, this distinction is particularly important. A party representative may advance every properly arguable aspect of the client’s case. An independent expert cannot. The expert must disclose weaknesses, recognise legitimate alternative opinions and maintain independence even where the conclusion is commercially unhelpful to the instructing party.

What should experts and instructing parties do before November 2026?

The transition period should be used positively.

Experts should review and, where necessary, update:

conflict-checking procedures;
terms of engagement;
initial instruction and acceptance letters;
fee-estimate wording;
provisions relating to assistants and subcontracted work;
policies concerning AI and analytical tools;
report structures and declarations;
procedures for document retention;
processes for reviewing changing instructions;
protocols for expert meetings and joint statements; and
arrangements for correcting or amending reports.

Instructing solicitors and clients should also consider whether their expert appointment processes provide sufficient clarity regarding:

the precise discipline required;
the expert’s relevant project and dispute experience;
previous involvement;
potential financial or professional conflicts;
the distinction between advisory and expert work;
the information needed to provide a realistic fee estimate;
the extent of any work undertaken by assistants; and
the assumptions upon which the expert is being asked to report.

Implications for quantum and professional negligence appointments

The fifth edition is particularly relevant to my work as an expert witness in construction disputes.

My quantum instructions commonly require examination of valuations, final accounts, variations, loss and expense, termination accounts, defective work costs and the financial consequences of alleged contractual breaches.

My professional negligence instructions involve consideration of whether services provided by quantity surveyors, employer’s agents, contract administrators, project managers and other surveying professionals were performed with the reasonable skill and care expected in the circumstances.

Although the subject matter differs, both disciplines depend upon the same fundamentals:

correctly identifying the issues requiring expert opinion;
working within the expert’s genuine area of competence;
examining the contemporaneous records rather than simply adopting the client’s case;
separating fact, assumption and opinion;
addressing evidence that may undermine the instructed position;
explaining the applicable professional or valuation methodology;
showing the reasoning that leads from the evidence to the conclusion; and
maintaining independence throughout the appointment.

A robust expert report should help the tribunal understand the issues. It should also assist the parties in evaluating risk, identifying areas of agreement and, where possible, resolving the dispute without a final hearing.

Conclusion

The fifth edition does not alter the essential character of expert evidence. The expert’s overriding duty remains to the tribunal, and independence remains the foundation upon which the credibility of the evidence rests.

What the new edition does is articulate those obligations more clearly and adapt them to the realities of modern expert practice. It introduces greater transparency concerning conflicts and fee arrangements, more explicit requirements around the use of assistants and artificial intelligence, firmer protections against interference with reports and a stronger emphasis on reasoned, case-specific evidence.

The fourth edition remains applicable until the fifth edition takes effect on 30 November 2026. Experts should not wait until that date before considering the changes. The transition period provides a valuable opportunity to ensure that appointments accepted now, but which may continue beyond November, are managed in a way that will satisfy the new professional standard.

For clients and solicitors, the fifth edition also provides a helpful reminder that expert evidence is not simply another form of representation. Its strength lies in the expert’s independence, relevant experience and willingness to provide a balanced opinion, whether or not every conclusion supports the party responsible for the expert’s fees.

The fifth edition professional standard and accompanying practice guidance are available free from RICS here: https://www.rics.org/profession-standards/rics-standards-and-guidance/sector-standards/dispute-resolution-standards/surveyors-acting-as-expert-witnesses