Integrity, Independence and Impartiality

Welcome to ExpertQS. We provide first-rate quantum expert witness services, quantity surveying services, and dispute resolution services within the building and construction industries.

ExpertQS works with solicitors, developers, land owners, construction professionals, and private parties to advise on a wide range of building and construction cost and quantum disputes. We also offer specialist quantity surveying and project management services.

The company is operated by Gary A Bushell, FRICS, MAE, QDR, APAEWE and our office is located in Windermere, among the beautiful South Lakes in the county of Cumbria in the northwest of England.

With a long-established reputation for integrity, independence and impartiality, Gary has over 40 years€™ experience dealing with a wide array of clients all over the country. He has successfully acted as expert witness and provided dispute resolution services in numerous cases and earned high regard from clients and solicitors as a professional quantity surveyor and expert witness. You can contact Gary on 01539 443 009 or 07989 503 707 or email him on gbushell@expertqs.co.uk.

Experience and qualifications

If you are looking for a strong expert witness, you’€™ll value rich experience. Gary is one of the few expert witnesses in the northwest dedicated to quantity surveying and construction cost issues. He acts as expert for claimants and defendants in connection with quantity surveying disputes, and he specialises in the following areas of practice:

  • Construction quantum expert witness services
    • Acting as expert witness for one or all parties to a dispute, preparing expert reports, and giving oral evidence in court and other hearings and tribunals.
  • Quantity surveying services
    • Providing construction cost, quantum and contract advice, development appraisals and planning economic viability assessments.
  • Dispute resolution services
    • Acting as expert determiner and acting as expert adviser in litigation, arbitration, adjudication and mediation proceedings, together with planning inquiries.

Gary is a accredited member (MAE) of The Academy of Experts, and adheres to its codes of practice and guidance. The Academy of Experts is the international centre of excellence for experts, promoting high objective standards. He strongly believes in impartiality, attention to detail, and meeting deadlines on time.

In addition, Gary is a Fellow (FRICS) of the Royal Institution of Chartered Surveyors which is a mark of distinction recognised by other professionals, the construction industry, and the public as denoting the highest standards of success, achievement and expertise in his specialism.

Gary complies with the RICS professional ethical standards which deal with integrity, levels of service, trust, respect and responsibility. He is an accredited member of the RICS Expert Witness Registration Scheme (EWRS) and he uses his experience and expertise to mentor others, including prospective RICS candidates.

Gary is a Qualified Dispute Resolver (QDR), he is a member of The Academy of Experts’ Register of Qualified Expert Determiners, and he recently attained the Advanced Professional Award in Expert Witness Evidence accredited by Edexcel to masters level (APAEWE).



As managing director of Bushell Raven Ltd up to 2013, Gary built up a quantity surveying practice that continues to prosper under the stewardship of his sons Jon and Ed, delivering traditional quantity surveying services and project management services to the South Lakes, Cumbria, the northwest and beyond.

With Gary’s track record, qualifications, and experience, you can be sure of a high quality construction quantum expert witness service with a straightforward and robust but professional approach to dispute resolution.

Please take a look at Gary’s services, articles, testimonials, and case studies. Once you have seen what he can do, call Gary today on 01539 443 009 or 07989 503 707 for a chat about how he can help. Alternatively you can email him on gbushell@expertqs.co.uk.