An expert witness is an independent professional with specialist knowledge who gives opinion evidence to a court, tribunal or arbitrator on matters within their expertise. Expert evidence can be required in disputes across land, property and construction, in fields such as quantity surveying, building surveying, valuation, dilapidations, planning and compulsory purchase.
In construction disputes a quantum expert, usually a chartered QS, assesses the value of work, variations, loss and expense or defects, while a delay expert analyses the programme and the causes of delay. The expert’s overriding duty is to the court or tribunal, not to the party paying them; in England and Wales this is set out in Part 35 of the Civil Procedure Rules. RICS members acting as expert witnesses must also follow the relevant RICS professional standard. Independence matters: an expert seen to be advocating for their client’s case will carry little weight.
Related terms: Dispute Resolution, Quantum, Adjudication, Arbitration.
