What is Part 35 Compliance? Expert Witness Requirements Explained
Expert Surveyors UK provides Part 35 compliant expert witness services for property disputes across the UK. Understanding Part 35 of the Civil Procedure Rules is crucial for anyone instructing an expert witness or acting as one in litigation, tribunal proceedings, or arbitration cases.
In this comprehensive guide, our RICS chartered surveyors explain what Part 35 compliance means, why it matters, and how it affects expert witness evidence in property disputes involving building defects, boundary disputes, valuations, and other surveying matters.
Understanding Part 35 of the Civil Procedure Rules
Part 35 of the Civil Procedure Rules (CPR) governs expert evidence in civil proceedings in England and Wales. These rules establish how expert witnesses should be instructed, what their duties are, and how their evidence should be presented to assist the court.
The fundamental principle of Part 35 is that expert witnesses have an overriding duty to the court that supersedes any obligation to the party instructing them. This ensures expert evidence remains impartial and objective, helping judges and tribunals reach fair decisions based on reliable expert opinions.
At Expert Surveyors UK, our chartered surveyors understand these requirements intimately. We've acted as expert witnesses in hundreds of property disputes, providing Part 35 compliant reports that withstand scrutiny in litigation across residential and commercial properties throughout the UK.
The Overriding Duty to the Court
The most important aspect of Part 35 compliance is the expert witness's duty to assist the court. This duty overrides any obligation to the instructing party, whether they're paying for the expert's services or not.
What this means in practice:
- Expert opinions must be impartial and unbiased
- Experts cannot act as advocates for either party
- Evidence must fall within the expert's area of expertise
- Experts must not mislead the court by omission or commission
- All relevant matters must be considered, even if unfavorable to the instructing party
Our building surveyors at Expert Surveyors UK take this duty seriously. When we provide expert witness services for property disputes, boundary disputes, or negligence claims, our primary concern is assisting the court with accurate, objective opinions on building matters within our expertise.
Independence and Objectivity
Part 35 requires experts to be independent. This doesn't mean experts can't be instructed by one party – they can and often are. Independence means the expert's opinion isn't influenced by who's paying them or what outcome would benefit the instructing party.
Expert Surveyors UK maintains independence by:
- Basing opinions solely on evidence and expertise
- Acknowledging uncertainties and limitations
- Considering alternative explanations
- Changing opinions if new evidence emerges
- Refusing instructions that compromise independence
Essential Requirements for Part 35 Compliant Reports
Part 35 specifies what expert witness reports must contain. Our RICS expert witnesses at Expert Surveyors UK ensure every report includes these mandatory elements:
1. Details of the Expert's Qualifications
Reports must state the expert's qualifications and experience relevant to the matters they're opining on. This establishes their expertise in the particular field.
Our chartered surveyors are RICS registered valuers, accredited by the Royal Institution of Chartered Surveyors, CIOB, and RPSA. We clearly state our qualifications, years' experience, and relevant expertise in building surveying, building pathology, and expert witness work.
2. Statement of Truth
Every Part 35 compliant report must include a statement of truth confirming:
- The expert understands their duty to the court
- They have complied with that duty
- The report contains their true, complete, and honest opinion
This statement makes experts accountable for their evidence and reinforces the seriousness of their duty to assist the court rather than advocate for instructing parties.
3. Declaration of Compliance
Reports must explicitly state that the expert has complied with Part 35 and any applicable practice directions. This declaration confirms the expert understands the rules and has followed them throughout their instruction.
4. Instructions Received
Part 35 reports must summarize the instructions received by the expert. This helps the court understand what the expert was asked to do and ensures transparency about the scope of their investigation.
5. Separation of Facts from Opinion
One of the most critical requirements is clearly distinguishing facts from opinions. Experts must identify:
- Facts they've observed or been told
- Facts they've assumed (with clear identification of assumptions)
- Their expert opinion based on those facts
- The reasoning behind their opinions
At Expert Surveyors UK, our building surveyors structure reports to make this distinction crystal clear. When we inspect properties for structural defects, boundary disputes, or building works failures, we document facts separately from our expert opinions about causes, implications, and remedial works needed.
6. Range of Opinion
Where there's a range of possible opinions on an issue, Part 35 requires experts to identify that range and explain why they've adopted their particular view within it. This demonstrates balanced consideration of alternatives rather than blind advocacy.
7. Summary of Conclusions
Reports must include a summary of conclusions, making it easy for courts to understand the expert's key findings without reading the entire detailed report.
8. Statement of Matters Outside Expertise
If an expert's opinion depends on matters outside their expertise, they must clearly state this. For example, our building surveyors might note when structural calculations require input from a structural engineer, or when legal interpretation affects our expert opinion on building regulations compliance.
The Single Joint Expert Approach
Part 35 encourages parties to agree on jointly instructing one expert – a single joint expert (SJE) – rather than each party appointing their own. This approach can reduce costs and streamline proceedings.
Expert Surveyors UK regularly acts as single joint experts when parties agree to jointly instruct one expert for property disputes, boundary disputes, party wall matters, or dilapidations cases. As SJEs, we provide impartial opinions that assist the court while potentially reducing litigation costs for both parties.
Benefits of Single Joint Experts
- Reduced overall expert costs (one expert instead of two)
- Faster dispute resolution
- Less adversarial proceedings
- Single, clear expert opinion for the court
- Reduced risk of conflicting expert evidence confusing issues
When Single Joint Experts Work Best
SJE appointments work particularly well for:
- Straightforward property valuations
- Building condition assessments
- Boundary disputes where facts are relatively clear
- Party wall matters requiring impartial assessment
- Dilapidations schedules in landlord and tenant disputes
However, in complex negligence claims or highly contentious property disputes, parties may prefer appointing separate experts.
Meetings of Experts and Joint Statements
Part 35 allows courts to direct experts to meet and discuss issues. These "without prejudice" meetings aim to narrow issues in dispute and identify areas of agreement and disagreement.
Following expert meetings, experts must prepare joint statements identifying:
- Matters on which they agree
- Matters on which they disagree
- Reasons for any disagreement
- Action needed to resolve disagreements if possible
Our chartered surveyors have extensive experience participating in expert meetings for property disputes. We approach these professionally, focusing on areas where our expertise can help parties agree on facts and narrow disputes to genuinely contentious issues.
Written Questions to Experts
Part 35 allows parties to put written questions to experts, either their own or opposing experts. These questions must:
- Be for clarification of the expert report
- Be proportionate
- Be submitted within 28 days of receiving the report
Experts must answer questions within a reasonable time, with answers forming part of their expert evidence. At Expert Surveyors UK, we respond thoroughly to written questions, treating them as opportunities to clarify our expert opinions and ensure the court fully understands our evidence.
Common Part 35 Compliance Issues
Not all expert witness reports meet Part 35 requirements. Common failures we've seen include:
1. Advocacy Rather Than Impartiality
Some experts slip into advocating for the instructing party rather than assisting the court. This compromises their independence and can lead to reports being rejected or given little weight by courts.
2. Opinions Outside Expertise
Experts sometimes offer opinions on matters outside their area of expertise. Our building surveyors carefully confine opinions to building surveying, building pathology, and property valuation – areas within our expertise – rather than straying into legal or structural engineering territory.
3. Inadequate Reasoning
Part 35 reports must explain the reasoning behind conclusions. Simply stating opinions without explaining how you reached them doesn't assist the court effectively.
4. Failing to Consider Alternative Views
Robust expert evidence acknowledges and addresses alternative explanations or opinions. Ignoring contrary evidence or plausible alternatives weakens expert reports.
5. Missing Mandatory Declarations
Forgetting required declarations – statement of truth, compliance statement, etc. – renders reports non-compliant and potentially inadmissible.
Part 35 in Different Types of Property Disputes
Expert Surveyors UK applies Part 35 principles across various property matters:
Building Defects and Negligence Claims
When property buyers discover defects after purchase, or builders produce defective building works, our expert witness services help establish what went wrong, why, and what remedial works are needed. Part 35 compliance ensures our evidence on building pathology issues assists courts in determining liability and damages.
Boundary Disputes
Boundary disputes between neighbors often require expert evidence on interpreting land registry plans, historical documents, and physical features. Our impartial opinions help tribunals resolve disputes across land boundaries fairly.
Party Wall Matters
While most party wall matters resolve without litigation, when party wall disputes reach court, Part 35 compliant evidence on building works impacts and party wall procedures becomes crucial.
Dilapidations
In landlord and tenant disputes over commercial property condition at lease end, our expert opinions on diminution in value, necessary remedial works, and reasonable repair standards must comply with Part 35 to assist courts in determining fair dilapidations settlements.
Housing Disrepair
Housing disrepair claims by tenants against landlords require expert evidence on property condition, landlord obligations, and effects on tenants. Our Part 35 compliant reports provide objective assessments that help courts determine appropriate remedies.
The Importance of RICS Registration for Expert Witnesses
While Part 35 doesn't require experts to be RICS registered, having RICS chartered surveyors provide expert evidence offers significant advantages:
- Professional regulation by the Royal Institution of Chartered Surveyors
- Mandatory professional indemnity insurance
- Continuing professional development requirements
- Code of conduct emphasizing integrity and objectivity
- Complaints procedures if conduct falls short
Expert Surveyors UK's RICS registered valuers bring not just expertise in building surveying but also professional accountability that reinforces Part 35 compliance.
Costs and Part 35 Expert Evidence
Expert witness fees are usually recoverable costs if you win your case, but courts assess whether those costs were reasonably incurred and proportionate. Part 35 compliance supports cost recovery by demonstrating expert evidence was properly obtained and genuinely assisted the court.
Courts may reduce or disallow expert costs if:
- Expert evidence wasn't necessary
- The expert wasn't appropriately qualified
- Reports weren't Part 35 compliant
- Experts acted as advocates rather than impartial assessors
How to Instruct Part 35 Compliant Experts
When instructing expert witnesses for property disputes, ensure:
- Clear written instructions defining the scope of work
- Confirmation the expert understands Part 35 duties
- Agreement on reporting format and timescales
- Understanding of the expert's role and limitations
- Provision of all relevant documents and information
At Expert Surveyors UK, we guide solicitors and parties through the instruction process, ensuring our expert witness services meet all Part 35 requirements from the outset.
Conclusion: The Value of Part 35 Compliance
Part 35 compliance isn't just a procedural requirement – it's fundamental to fair dispute resolution. By ensuring expert witnesses provide impartial, objective opinions to assist courts rather than advocate for parties, Part 35 protects the integrity of civil justice.
Expert Surveyors UK's chartered surveyors bring extensive experience providing Part 35 compliant expert witness services for property disputes across residential and commercial properties throughout the UK. Our knowledge and expertise in building surveying, combined with thorough understanding of expert witness requirements, ensures the evidence we provide assists courts effectively while withstanding scrutiny in litigation and tribunal proceedings.
Whether you need an independent expert appointed by one party or parties agree to jointly instruct one expert as a single joint expert, our RICS registered team delivers expert reports that comply fully with Part 35 of the Civil Procedure Rules.
Need Part 35 Compliant Expert Witness Services?
Expert Surveyors UK provides Part 35 compliant expert witness reports for property disputes across the UK. Our RICS chartered surveyors offer impartial, objective opinions that assist courts effectively.
Contact Our Expert Witnesses