A Single Joint Expert (SJE) is one expert instructed jointly by both parties to a dispute, paid by both, and reporting once — to the court, not to either side. Under CPR 35.7 the court can direct that expert evidence be given this way, and for proportionate property disputes it increasingly does. Here's how SJE instruction works, what it costs, and the rights each party keeps.
When courts direct a Single Joint Expert
SJEs are the default direction where the sums at stake don't justify duelling experts: lower-value building defect claims, boundary disagreements, matrimonial property valuations, disrepair claims and most fast-track matters. The logic is proportionality — one impartial report costs half as much and removes the battle-of-experts dynamic. Higher-value or genuinely contested technical matters still see party-appointed experts on each side.
How an SJE is chosen and instructed
Typically each side proposes a shortlist and they agree one name (failing agreement, the court selects). Both parties then send instructions — jointly where possible, separately where not, with each side's instructions disclosed to the other. The expert inspects, and delivers one report served on both parties simultaneously. The expert's duty throughout is to the court under CPR Part 35 — which is why the SJE's independence matters more than either side's preferences.
Who pays a Single Joint Expert?
Both parties, usually in equal shares, and both are jointly liable for the fees. Typical property SJE instructions run from a few thousand pounds — materially cheaper than two opposing experts plus a joint statement process. Fee terms are agreed before instruction; success-based fees are prohibited.
Your rights after the SJE reports
You are not stuck with a report you dislike — but your options are structured. Either party may put written Part 35 questions to the expert (once, within 28 days, for clarification). A party genuinely dissatisfied can seek the court's permission to instruct its own expert — granted sparingly, and usually only where the SJE's report has real deficiencies. What you cannot do is privately coach or confer with the SJE; all communication is shared.
SJE vs party-appointed expert at a glance
SJE: one report, shared cost, faster, no joint-statement stage — but you surrender control of expert selection. Party-appointed: your own expert plus theirs, Part 35 questions, joint statements narrowing issues — stronger for complex, high-stakes technical disputes. Read what an expert witness does for the wider role.
SJE appointments through Survey Merchant
Our RICS surveyors accept SJE appointments across England and Wales — building defects, party wall and boundary matters, valuations — with expert witness teams in London, Leeds, Guildford and Surrey and specialist construction expert witness capability. Because both sides must accept the name, our experts' CVs lead with independence: Part 35 training, no prior connection to either party, fixed fees.
Need an SJE both sides can accept? Request CVs and a joint fee quote → contact us.
