Cross-Examination of an Expert Witness Surveyor: What to Expect

Expert witness cross examination is the part of a property trial that most surveyors think about long before they reach the witness box. The written report has been served, Part 35 questions answered and the joint statement signed, and then an advocate stands up whose job is to test every assumption in that report in front of the judge. This guide explains what cross-examination of an expert witness surveyor involves in the English and Welsh courts, how a well-prepared expert handles it, and what solicitors and litigants should expect when a case reaches a hearing. For the wider role, see the guide to expert witness services.

When does an expert witness surveyor have to attend court?

Less often than most people assume. Under CPR 35.5, expert evidence is given in a written report unless the court directs otherwise, and on the fast track the court will not direct an expert to attend a hearing unless it is necessary in the interests of justice. On the small claims track, expert evidence is only admitted with the court's permission and is almost always written. Most property disputes settle after reports are exchanged or after the joint statement of experts narrows the issues.

Oral evidence becomes likely on the multi-track and intermediate track where the experts still disagree on an issue the judge must decide: the cause of a defect, the cost of repair, the value of a property at a past date, or whether a surveyor fell below the standard of a reasonably competent professional. Party-appointed experts in a disputed case should assume they will be called.

How the hearing works: evidence-in-chief, cross-examination and re-examination

At trial the expert's report normally stands as their evidence-in-chief. The advocate who called them may ask a few questions to confirm the report and correct any errors, but there is no retelling of the whole opinion. Cross-examination by the opposing advocate follows, and it is this stage that tests the evidence. Re-examination by the expert's own side is limited to matters raised in cross-examination, and the judge may ask questions at any point.

Where the court has ordered concurrent evidence under Practice Direction 35, the experts give evidence together with the judge leading the questioning. The guide to hot-tubbing in property cases covers that format; this article deals with conventional cross-examination.

A surveyor giving evidence in a building defects claim might be in the box for an hour, or for most of a day in a complex construction or professional negligence trial. Court attendance is typically charged at £1,000 to £2,000 per day on top of the report fee, which is one reason the cost of expert evidence rises sharply once a case is listed for trial.

What does cross-examination of an expert witness test?

Cross-examination of an expert is not an attempt to re-run the survey. The advocate works from the report, the joint statement, the other expert's evidence and the documents, and the questions group around a few themes that follow from the expert's duties under CPR 35.3 and Practice Direction 35.

• Expertise and scope. Is the surveyor actually qualified to give this opinion? A building surveyor asked about structural adequacy, or a valuer asked about construction cost, can expect the advocate to probe the edge of their expertise. PD35 requires an expert to say when a question falls outside their field, and a witness who does so loses nothing.
• Independence and instructions. Who instructed the expert, on what basis, and has the opinion been shaped by the instructing party? The statement of instructions in the report is fair game.
• Facts, assumptions and inspection. What did the surveyor actually see, measure or test, and what has been assumed? Any limitation on access recorded in the report will be put to the witness.
• Methodology and the range of opinion. Why this method of analysis, this comparable, this cost rate? PD35 requires the report to summarise the range of opinion where one exists and give reasons for the expert's own view, and cross-examination usually tests whether those reasons hold.
• Consistency. Anything the expert has said elsewhere is material: the joint statement, answers to written questions under CPR 35.6, an earlier report or published articles. A change of view is not fatal provided it has been explained and notified promptly, as the rules require.
• Concessions. The advocate will seek agreement on individual propositions that, added together, undermine the conclusion. A good expert agrees with what is true and declines what is not.

The principles courts apply when weighing expert evidence were set out in the Ikarian Reefer case and are reflected in Practice Direction 35: evidence should be independent, uninfluenced by the pressures of litigation, confined to the expert's own expertise, clear about the facts and assumptions relied on, and candid about any matter that cannot be answered properly. A report written to that standard has already done most of the work.

How an expert witness surveyor prepares for cross-examination

Preparation starts with the expert's own report. The panel's experts re-read the report, the joint statement and the opposing report in full before the hearing, with the site notes, photographs and measurements to hand, so that any figure quoted in the report can be traced to its source. Knowing the file is what separates a witness who looks authoritative from one who looks caught out.

Next comes the weak points. Every report has them: an assumption that could not be verified, an ageing comparable, an area that could not be inspected. The expert should identify these before the advocate does and be ready to explain why the opinion survives them. A conference with counsel before trial is normal for this purpose, provided it clarifies the evidence rather than coaching the witness.

In the box the conventional advice holds. Answer the question asked, briefly, and stop. Address answers to the judge rather than the advocate. Ask for a question to be repeated if it is compound or unclear. Say so when the answer is not known or the point is outside the surveyor's expertise. Never argue the client's case; the expert's duty under CPR 35.3 is to the court, which overrides any obligation to the instructing party, and judges notice quickly when a witness has forgotten that. The RICS practice statement on expert witnesses makes the same point.

What happens if cross-examination goes badly?

An expert whose evidence is rejected does not simply lose the point. The judgment may record that the witness was partisan, strayed beyond their expertise or failed to engage with the other side's evidence, and those findings are public. Since Jones v Kaney removed expert witness immunity in 2011, a client whose claim failed because of a negligent expert can sue, and the court can also order a party's expert to pay wasted costs in cases of serious breach of duty. Solicitors checking an expert witness CV look for court experience precisely because of this.

The flip side is that cross-examination is where a careful expert earns their fee. An opinion that is tested by a skilled advocate and comes through intact carries far more weight with the judge than one that was never challenged, and judgments in property cases often turn on which expert was prepared to make sensible concessions.

Expert witness surveyors from Survey Merchant

Survey Merchant provides RICS chartered surveyors as expert witnesses for property disputes across England and Wales, drawn from a national panel of 2,400+ surveyors. The panel's experts prepare CPR Part 35 compliant reports, take part in joint statements, answer written questions and give oral evidence where the court directs it, in building defects, dilapidations, party wall, boundary, valuation and surveyor negligence cases, including construction disputes and hearings in the London courts. Fixed fees are quoted for the report stage, with court attendance at a daily rate agreed in advance. Contact Survey Merchant or call 0204 579 8270 to be matched with an expert who has experience of giving evidence under cross-examination.