A building expert witness is a qualified construction professional - typically a chartered building surveyor, quantity surveyor, structural engineer or contractor - who is appointed to give independent technical opinion in a legal dispute. Their primary duty is to the court or tribunal, not to the party instructing them, and they must comply with CPR Part 35 (in court proceedings) or equivalent procedural rules. Expert witnesses in construction disputes commonly address issues of defective workmanship, design liability, quantum of damages, delay and disruption, and the standard of care expected of building professionals.
What they do
- Inspect defective buildings and construction work to assess cause and extent of defects
- Produce expert witness reports compliant with CPR Part 35
- Advise instructing solicitors on the merits of technical arguments
- Prepare schedules of defects and remediation cost assessments
- Attend without prejudice expert meetings and produce joint statements
- Give oral evidence at trial, arbitration or public inquiry
- Act as court-appointed single joint expert (SJE)
- Advise on the standard of care expected of contractors and designers
- Produce quantum of damages reports for defective work claims
When you need one
A building expert witness is needed when a legal dispute involves technical building issues that the court or tribunal cannot assess without specialist expert opinion.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Expert witness hourly rate | £150 - £350 / hr |
| Expert report (standard) | £2,000 - £8,000 |
| Joint statement with opposing expert | £800 - £2,500 |
| Court attendance (per day) | £800 - £2,000 |
| Preliminary advice and case assessment | £500 - £1,500 |
Fees depend on the expert's seniority and the complexity of the technical issues. Senior RICS fellows and well-known construction experts command premium rates. Always agree a fee estimate before instructing.
Frequently asked questions
What is an expert witness?
An expert witness is a person with specialist knowledge and experience who is appointed to give independent expert opinion to a court, tribunal or arbitrator on technical matters that are beyond the understanding of a lay person. Unlike a professional witness who gives factual evidence, an expert witness gives opinion evidence within their area of expertise.
What duty does an expert witness owe?
Under CPR Part 35, an expert witness appointed in court proceedings owes an overriding duty to the court rather than to the party who appointed them. The expert must be objective and impartial - they must not act as an advocate for the party who instructed them. This duty overrides any obligation to the instructing party.
What qualifications does a building expert witness need?
No specific qualification is required but demonstrable expertise is essential. Relevant professional qualifications (MRICS, MCIOB, CEng), Fellowship of the Expert Witness Institute or membership of the Academy of Experts are positive indicators. The expert must be able to demonstrate sufficient relevant experience to give credible opinion evidence on the specific technical issues in dispute.