The frequency of disputes involving real property means that many property professionals, valuers in particular, will be asked to act as an expert witness at some point in  their career. This can be a lucrative line of business and there are numerous practitioners who do  little more than act as experts. However, the way expert evidence is gathered and delivered, and  the status given to expert witnesses, has changed considerably over the last few years. Anyone  thinking of acting as an expert witness needs to understand the risks and responsibilities involved  before agreeing to take on this role.

Status of expert witnesses

For many years both factual and expert witnesses enjoyed immunity from prosecution in respect of  deficiencies in their evidence. For expert witnesses this position changed following the decision  of the Supreme Court in Jones v Kaney (2011) in which Lord Dyson held that:

“…immunity of expert witnesses from liability to their clients for breach of duty (whether in  contract or negligence) can no longer be justified…”

Since Jones v Kaney there have not been any reported judgments finding an expert witness liable for  deficient evidence. However not six months after this landmark decision its impact was felt by one  particular expert. In Warner v Penningtons (2011) Mr Warner alleged that his claim was settled for  too little as a result of negligent advice from his solicitors, Penningtons. Penningtons denied the  allegation but also argued that if the claim had been under-settled it was due to the negligent  advice of their expert witness. The expert was joined in to the proceedings but made an application  for summary judgment on the basis that there was no prospect of showing that she was negligent. She  also made an application to strike out the claim on the ground that she was immune, but this was  stayed pending Jones v Kaney and then dropped. The Court, at both first instance and on appeal,  found for the expert. This appears to be one of the first cases where the loss of immunity led to an expert having to  mount a proper defence against an allegation of deficient evidence.

Whilst there has not been a flood of claims against expert witnesses, we anticipate this will be an area of increasing exposure. Just as claims against  solicitors and barristers in respect of lost litigation are becoming more prevalent, we are also  seeing a gradual increase in the volume of claims against experts. We are therefore likely to see  further judicial commentary soon.

Set out below are examples of risks that any professional contemplating acting as an expert should  be aware of in order to protect themselves, not only from potential claims, but also the  reputational risk of criticism in a public court hearing.

Independence and impartiality

Part 35 of the Civil Procedure Rules (CPR) sets out the rules applicable to expert witnesses in  court proceedings. Most other forums, such as arbitration, will expect the same.  CPR 35.3 confirms  that the expert’s overriding duty is to the Court and not the party providing instructions or  payment. It states:

“It is the duty of experts to help the Court on matters within their expertise”

“This duty overrides any obligation to the person from whom the experts have received instructions  or by whom they are paid”

Prospective experts must therefore ensure that they obtain details of all parties at the outset,  including the opponent expert witness, and consider carefully whether their involvement would  create any risk of their impartiality, independence and objectivity being compromised. 

Even if there is only a small risk of the expert being criticised for being partisan that should be drawn to the attention of the instructing party at the  earliest possible stage. The evidence of a partisan expert witness will carry far less weight for a  judge than that of someone who is wholly independent. If this were to become an issue the expert  would be well-advised to have the ability to say that it was a risk that the client knowingly took,  so the expert cannot be criticised.


Every prospective expert witness must consider carefully whether he or she has the appropriate  expertise to assist the court. The dangers of over-selling should not be underestimated. Of  particular relevance to experts in the property market will be their sector and geographical  experience. Judges regularly prefer the evidence of the expert who is most familiar with the market  in question.

Again, experts should be frank about their CV and bear in mind that the party instructing them may  not know what the “right” experience looks like. Full disclosure will give the expert the maximum  protection.

Terms and conditions

Expert witnesses should agree and document their terms of appointment in much the same fashion as  any other professional appointment so as to ensure maximum certainty and protection. The terms  should specify at least:

  • The scope of the appointment
  • The basis upon which the expert will be paid
  • Any agreed liability caps or exclusions
  • Any agreed timescales for the expert’s services


It is essential that an expert receives clear and concise instructions so that the scope of the  duty to the instructing party will not be in any doubt. If there is any uncertainty always clarify  the position, and remain within the scope of any instructions, bearing in mind there is a  requirement to give full and frank evidence to the Court. To prevent any tensions arising between these two  obligations any other issues or developments should be raised as soon  as possible, so that a  decision can be made as to whether they should be addressed by the expert or not. Clear lines of communication and good record-keeping  are important risk management tools in this regard.


The wide-ranging Jackson reforms have not just impacted solicitors; there are important points  arising from the reforms for experts to consider. Significant issues arise regarding the  preparation of a litigant’s Precedent H costs budget. An expert will be asked to provide an  estimate of their fees at an early stage of the proceedings. Unless there are good reasons for a change,  such as the addition of new issues for the expert to address, the litigant is  likely to be held to  those costs figures at the end of the proceedings. If the fees are underestimated the client may  suffer a shortfall. On the other hand, if the estimate is too high this may allow the opposing  party to also submit an unreasonably high figure, leading, if they are successful in the litigation, to the client paying a greater sum to  the opposing party in costs than should  properly be the case. Careful consideration and the use of assumptions/ caveats are required and estimates should be updated and reviewed regularly.

In Phillips v Symes (2004) Peter Smith J held that courts may make orders for costs directly  against expert witnesses who cause significant expense to be incurred, and do so in flagrant and reckless disregard of their duties to the Court. It is too early to know whether an  expert who fails to properly consider the level of fees provided to instructing solicitors will be  considered to have been sufficiently reckless and flagrant to have a costs order made against  him/her, but the potential is there.


Due to the changing risk landscape that experts now face and the criticism that has recently been  directed by the court at poor quality experts, training is often advisable, particularly for those  without prior experience of giving evidence in court. A prime example is Board of Trustees of National Museums & Galleries v AEW Architects (2013) in which an expert was described as  “…wholly unimpressive, possibly partly because he had never given expert evidence before…it was  clear that he had given little or no coherent thought to the issues in the case”. As a result, the  judge found the expert “wholly unconvincing about all aspects of liability…”

This is obviously an extreme case of the Court criticising an expert, although it should be noted  that the judge, Mr Justice Akenhead, does have a history of criticising experts (see Igloo  Regeneration v Powell William Partnership [2013], Walter Lilly v Mackay [2012], and, most recently,  Weatherford Global Products Limited v Hydropath Holdings Limited and Others [2014])

It should go without saying that it is important for an expert to be as prepared as possible for what the appointment entails, such as being aware of the duties  that he/she owes and tasks he/she will have to undertake, including both report-writing and,  potentially, giving evidence at trial.


A risk that should not be overlooked is the impact that an expert appointment can have on  commercial relationships.

Notwithstanding the requirement of independence, experts will often be perceived as taking sides in  a dispute. Property professionals will need to consider whether the risk of this perception may  cause them difficulties in maintaining existing commercial relationships or building new ones. We  know of firms in the property sector, and elsewhere, who do not take on expert witness work as a  matter of principle for this reason alone. The flipside of course is that when they need help from  a fellow professional, assistance for the  firm which refuses to act as expert witness can be  harder  to come by.


Finally, there are regulatory risks at play for RICS members in particular. RICS published the  fourth edition of its Practice Statement and Guidance Note “Surveyors acting as expert witnesses”  in July 2014: knowledge/professional-guidance/practice-statements/  surveyors-acting-as-expert-witnesses-4th-edition/. It is mandatory for RICS members to comply with  the Practice Statement and there may be disciplinary consequences  for any failure to do so. The  Guidance Note, whilst not mandatory, represents best practice in this area and should therefore be borne in mind in all  relation to all instructions to act as an expert. Choosing an expert witness Many of the issues referred to above apply equally to the party selecting and instructing an expert  witness (and their advisers). Prospects of success in litigation can be significantly increased by:

  • Selecting the right expert with the right expertise, qualifications and experience
  • Ensuring that the expert is instructed to consider all relevant issues
  • Guiding the expert through the process and supporting him or her whenever necessary

This should be the role of the solicitor advising on the litigation, but there may be cases where  the client has greater knowledge of the relevant issues, and so will be able to give important  assistance with a view to maximising these prospects.

Those selecting and instructing experts should have  regard to the new guidance document published  by the Civil Justice Council in August 2014, which can be found at experts-guidance-cjc-aug-14-amended1.pdf.  This guidance is expected to replace the Protocol for the Instruction of Experts, which currently  forms part of Practice Direction 35, in the next round of amendments to the Civil Procedure Rules in the autumn.


The role of an expert witness can be onerous and caution is required for those considering  accepting an expert appointment. However, in many respects the risks are not dissimilar to those  faced by property professionals in their regular work. For firms with appropriate risk management  procedures in place expert witness work can be a lucrative and professionally and intellectually  rewarding line of business.