What a CPR Part 35 Expert Witness Report Contains — and Why It Matters

If a property dispute is heading to court, the expert report is often the single most influential document in the bundle — and the court will only give it weight if it complies with Part 35 of the Civil Procedure Rules. Here is what a compliant expert witness report contains, who can produce one, and why cutting corners costs cases.

The expert's duty comes first

CPR Part 35's foundation is that the expert's duty is to the court — overriding any obligation to the instructing or paying party. A report that reads like advocacy is worth less than no report at all. That duty shapes everything below.

What the report must contain

Practice Direction 35 requires: the expert's qualifications; all literature and material relied on; a statement of the facts and instructions given to the expert; who carried out any inspections or tests and whether under the expert's supervision; a summary of the range of opinion where others could reasonably differ, with reasons for the expert's own view; a summary of conclusions; and — the parts courts check first — the expert's declaration that they understand and have complied with their duty to the court, and a signed statement of truth in the prescribed wording. In a building dispute you should also expect photographic schedules, measurements and analysis against Building Regulations and relevant standards.

Single Joint Expert or party-appointed

Courts increasingly direct a Single Joint Expert for proportionate disputes — one expert instructed and paid by both sides. In larger matters each party appoints its own expert, and the experts then answer written Part 35 questions and produce a joint statement narrowing the issues. A well-drafted report frequently settles the matter before trial: once causation and cost are credibly fixed, there is often little left to fight about.

Who can write one — and what it costs

Anyone with relevant expertise can technically act, but in property and construction disputes courts expect chartered professionals — an expert witness surveyor with MRICS/FRICS status, current training and insurance. Reports for straightforward matters typically cost £5,000–£15,000; complex multi-issue disputes more. Never accept success-based fees — they breach RICS rules and destroy the report's independence.

Instructing the right expert

Survey Merchant provides RICS surveyors as expert witnesses across England and Wales — construction expert witness instructions, party wall, boundary and valuation disputes — with dedicated teams in London, Leeds, Guildford and Surrey. Reports are CPR Part 35-compliant, delivered typically within 2–4 weeks of inspection. Request an expert CV and fee quote →