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Civil Procedure Rules Part 35: Complete Guide for Expert Witnesses

Civil Procedure Rules Part 35 (CPR Part 35) forms the cornerstone of expert witness work in England and Wales. Understanding and complying with Part 35 is essential for anyone acting as an expert witness. This comprehensive guide explains the rules, their practical application, and how expert witnesses should conduct themselves in legal proceedings.

Expert Witness RICS professionals strictly adhere to CPR Part 35 requirements, ensuring our expert evidence meets the standards expected by courts and tribunals. Whether you're a surveyor considering expert witness work or a solicitor instructing an expert, this guide provides the clear understanding you need.

What Are the Civil Procedure Rules?

The Civil Procedure Rules (CPR) govern the practice and procedure of civil courts in England and Wales. Introduced in 1999 following the Woolf Reforms, the CPR aims to make civil litigation more accessible, faster, and less expensive. Part 35 specifically addresses expert evidence and the role of expert witnesses.

Part 35 applies to all civil proceedings in the County Court, High Court, and the Court of Appeal (Civil Division). The rules also influence practice in tribunals and arbitration proceedings, where similar principles often apply even if Part 35 itself doesn't have direct force.

The Overriding Duty to the Court

The fundamental principle of CPR Part 35 is clear and unequivocal: an expert witness's overriding duty is to the court or tribunal, not to the party who instructs or pays them. This duty to the court trumps any obligation to the instructing party.

What This Means in Practice

Expert witnesses acting under Part 35 must:

• Provide Impartial Opinion: Base conclusions solely on expertise and evidence, never allowing the instructing party's interests to influence their professional opinion
• Never Oppose Truth: Present findings honestly, even if they don't support the instructing party's case
• Maintain Independence: Avoid becoming an advocate for either side
• Declare Limitations: Be transparent about the limits of their expertise and the certainty of their conclusions
• Correct Errors: Inform all parties promptly if they discover their report contains errors or if their opinion changes

This duty protects the integrity of the legal process. Courts rely on expert witnesses to provide reassurance that technical matters are being assessed objectively by qualified professionals. When experts compromise their impartiality, they undermine the entire justice system.

CPR 35.3: Expert Evidence Restriction

CPR 35.3 states that expert evidence should be restricted to what is reasonably required to resolve the proceedings. This means courts control when and how expert evidence can be used. Permission from the court is typically required before an expert can be instructed.

Court Permission Requirements

When seeking permission to instruct an expert witness, parties must demonstrate:

• The issues requiring expert evidence
• Why expert evidence is necessary
• The expert's area of expertise
• The likely cost
• Whether a single joint expert would be appropriate

Courts increasingly favor single joint experts to reduce costs and streamline proceedings. However, for complex property disputes involving significant sums, separate experts for each party may still be permitted.

Expert Witness Reports Under CPR Part 35

CPR 35.10 sets out detailed requirements for expert witness reports. These requirements ensure reports provide clear, useful evidence to the court.

Mandatory Report Content

Every expert report must include:

1. Details of Qualifications: The expert's qualifications, training, and experience relevant to the case
2. Statement of Instructions: A clear statement of the substance of all material instructions (written or oral)
3. Statement of Truth: "I confirm that I have made clear which facts and matters referred to in this report are within my own knowledge and which are not. Those that are within my own knowledge I confirm to be true. The opinions I have expressed represent my true and complete professional opinions on the matters to which they refer."
4. Statement of Compliance: Confirmation that the expert understands and has complied with their duty to the court
5. Matters Outside Expertise: Clear identification of any matters falling outside the expert's area of expertise
6. Sources of Information: Details of literature or other material relied upon
7. Range of Opinion: Where there is a range of professional opinion, a summary of that range and reasons for the expert's own opinion
8. Summary of Conclusions: A summary of the expert's conclusions
9. Qualifications and Caveats: Any qualifications to opinions expressed, including assumptions made, caveats, or limitations

Report Writing Best Practice

Beyond the mandatory requirements, expert reports should be:

• Clear and Accessible: Written in language the court can understand without unnecessary jargon
• Well-Structured: Organized logically with clear headings and numbering
• Properly Supported: Conclusions backed by evidence and reasoning
• Balanced: Acknowledging weaknesses in their own position and strengths in opposing views
• Professional: Maintaining objectivity throughout

At Expert Witness RICS, our expert report writing consistently meets and exceeds these standards, providing solicitors and courts with professional opinion they can rely upon.

Written Questions to Experts (CPR 35.6)

After an expert's report is served, the other party can put written questions to the expert. These questions must be solely for clarification of the report and must be put within 28 days of service (unless the court orders otherwise).

Responding to Written Questions

Expert witnesses must:

• Answer questions that are properly put within the time limit
• Provide answers in a reasonable time (or the court may direct a deadline)
• Treat the questions and answers as part of their expert evidence
• Consult with the instructing party before answering, but remain independent

Experts are not required to answer questions that go beyond clarification into new areas of expertise or that are inappropriate. If uncertain whether questions are proper, experts should seek guidance from their instructing solicitor or the court.

Discussions Between Experts (CPR 35.12)

Courts frequently order expert witnesses to hold discussions to identify areas of agreement and disagreement. These discussions serve a crucial function in narrowing issues and potentially avoiding the need for a full hearing.

The Purpose of Expert Discussions

Expert discussions aim to:

• Identify areas where experts agree
• Narrow the issues in dispute
• Understand the reasons for any disagreements
• Explore whether disagreements can be resolved
• Identify what further information might help resolve disputes

Joint Statements

Following their discussion, expert witnesses must prepare a joint statement setting out:

• Areas where experts agree
• Areas where experts disagree and a summary of their reasons
• Any actions that could be taken to resolve outstanding issues

The joint statement is not prepared for, or agreed with, the parties' legal representatives. It represents the experts' professional opinions. However, experts cannot be bound by agreements on matters outside their expertise or on questions that are for the court to decide.

Important Principles for Expert Discussions

• Without Prejudice: Discussions are usually without prejudice, meaning they cannot be referred to at trial unless in the joint statement
• No Legal Representatives: Lawyers typically do not attend expert discussions (unless exceptionally permitted)
• Professional Respect: Experts should engage constructively and professionally
• Independence Maintained: Experts must not compromise their opinions to reach agreement

Expert Witness RICS professionals are experienced in preparing joint statements that clearly identify areas of agreement while maintaining integrity on matters where genuine professional disagreement exists.

Giving Evidence at Trial

When property disputes proceed to trial, expert witnesses may be called to give oral evidence and face cross-examination. Understanding courtroom procedure and expectations is essential.

Examination-in-Chief

The instructing party's barrister will first question the expert (examination-in-chief). This typically involves:

• Confirming the expert's qualifications and experience
• Confirming the expert has read and understood their duties
• Taking the expert through key parts of their report
• Addressing any changes or clarifications since the report was prepared

Cross-Examination

The opposing party's barrister will then cross-examine the expert. This is where the expert's knowledge, professional opinion, and independence are tested. Cross-examination may involve:

• Challenging the expert's conclusions
• Questioning methodology or assumptions
• Highlighting inconsistencies or weaknesses
• Presenting alternative interpretations
• Testing the expert's knowledge of relevant literature or standards

Surviving Cross-Examination

RICS accredited expert witnesses prepare for cross-examination through:

• Thorough Preparation: Re-reading all reports, joint statements, and case documents
• Knowing Limitations: Being prepared to acknowledge what they don't know
• Staying Calm: Maintaining composure under pressure
• Taking Time: Pausing to consider questions before answering
• Being Honest: Never guessing or making up answers
• Addressing the Judge: Remembering their duty is to the court, not the barristers

Expert witness training typically includes mock cross-examination to help surveyors prepare for this challenging aspect of expert witness work.

Single Joint Experts

CPR 35.7 allows the court to direct that evidence on a particular issue be given by one expert instructed jointly by the parties. Single joint experts are increasingly common, particularly in lower-value disputes.

When Single Joint Experts Are Appropriate

Courts favor single joint experts when:

• The issue is relatively straightforward
• There is an established approach or methodology
• The case value doesn't justify the cost of separate experts
• Delay would be caused by separate experts

Challenges of Single Joint Expert Work

Acting as a single joint expert requires particular care:

• Balancing Instructions: Considering both parties' instructions fairly
• Independence: Avoiding perceived bias toward either party
• Communication: Ensuring both parties receive information simultaneously
• Questions: Responding to written questions from both sides
• Payment: Managing fee arrangements with both parties

Consequences of Non-Compliance with Part 35

Failure to comply with Part 35 can have serious consequences for expert witnesses and the parties who instruct them.

Potential Consequences Include:

• Evidence Excluded: The court may refuse to admit the expert's evidence
• Costs Penalties: The court may disallow the expert's fees or order costs against the instructing party
• Wasted Costs Orders: In serious cases, costs orders directly against the expert
• Professional Consequences: Complaints to professional bodies like RICS
• Reputation Damage: Loss of credibility with courts and instructing solicitors
• Negligence Claims: Since it became possible to sue experts in negligence, failure to comply with Part 35 could lead to professional negligence claims

The Practice Direction Accompanying Part 35

The Practice Direction to Part 35 provides additional detail on how the rules should be applied. Key provisions include:

• Guidance on the format and content of expert reports
• Details about expert discussions and joint statements
• Information about assessors appointed by the court
• Provisions about expert evidence in small claims

Expert witnesses should be familiar with both Part 35 itself and the accompanying Practice Direction.

Part 35 in Different Court Contexts

Fast Track Cases

In fast track cases (typically claims between £10,000 and £25,000), restrictions on expert evidence are tighter. Courts usually limit:

• The number of experts to one per party per field
• Expert evidence to written reports only
• The length of reports

Multi-Track Cases

Multi-track cases (over £25,000) allow more flexibility, but courts still encourage economy and proportionality in the use of expert evidence.

Small Claims Track

In the small claims track (under £10,000), expert evidence requires court permission and is relatively rare due to cost considerations.

Tribunals and Part 35

While Part 35 doesn't directly apply to most tribunals, tribunal procedures often mirror Part 35 principles. Expert witnesses in tribunal proceedings should still:

• Maintain independence and impartiality
• Recognize their duty to the tribunal
• Provide balanced professional opinion
• Comply with tribunal directions and procedures

Many tribunals have their own practice directions that address expert evidence, and these should be reviewed carefully.

Best Practice for Compliance

To ensure full compliance with CPR Part 35, expert witnesses should:

1. Undertake Training: Complete expert witness training covering Part 35 requirements
2. Use Templates: Develop report templates that include all mandatory content
3. Maintain Independence: Establish clear boundaries with instructing solicitors
4. Document Everything: Keep clear records of instructions, assumptions, and reasoning
5. Seek Guidance: Consult professional bodies or legal advisers when uncertain
6. Stay Updated: Monitor changes to the CPR and relevant case law
7. Review Work: Have reports peer-reviewed before submission
8. Professional Insurance: Maintain adequate professional indemnity insurance

Recent Developments and Case Law

CPR Part 35 continues to evolve through case law and amendments. Recent trends include:

• Increased Scrutiny: Courts are more willing to exclude expert evidence that doesn't comply with Part 35
• Proportionality Focus: Greater emphasis on proportionate use of expert evidence
• Hot-Tubbing: Growing use of concurrent evidence (experts giving evidence together)
• Technology: Adaptation to remote hearings and electronic disclosure

RICS accredited expert witnesses maintain their competency through continuous professional development, ensuring they stay current with procedural changes.

Conclusion

Civil Procedure Rules Part 35 provides the essential framework for expert witness work in England and Wales. Understanding and complying with Part 35 is not optional—it's fundamental to providing expert evidence that courts can rely upon.

The core principles are straightforward: expert witnesses owe their primary duty to the court, must provide impartial professional opinion, and must comply with detailed procedural requirements. However, applying these principles in practice requires expertise, experience, and commitment to professional standards.

Expert Witness RICS professionals undergo dedicated training in CPR Part 35 compliance and maintain their knowledge through continuous professional development. Our reports consistently meet the standards required, our experts excel at producing effective joint statements, and we have extensive experience of providing expert evidence under cross-examination.

Whether you're a surveyor considering expert witness work or a solicitor looking to instruct an expert witness, understanding Part 35 is essential. The rules protect the integrity of the justice system and ensure expert evidence serves its proper purpose: helping courts reach correct decisions on technical matters.