In professional negligence claims, expert evidence is essential. If there’s a concern that a professional has made a serious error, the court relies on input from someone qualified in the same field to assess whether that concern is justified. Without it, the claim is unlikely to succeed - except in cases involving lawyers, where judges may be able to assess the alleged negligence without external input.

The recent case of Bratt v Jones involved a dispute over land valuation and a claim of professional negligence against a valuer. Valuation disputes - especially when large sums are involved - are rarely straightforward. This case highlights the importance of giving your expert clear and complete instructions, particularly when the court is being asked to decide whether a professional has fallen below the required standard.

Case Background

Mr Bratt owned development land in Oxfordshire with planning permission for a housing project. Under an agreement with a developer, the land could be purchased at 90% of its market value. If the parties couldn’t agree on the value, an independent valuer would be appointed.

That’s what happened. Mr Jones, a professional valuer, was brought in and assessed the land at £4.075 million. Mr Bratt disagreed, believing the land was worth closer to £8 million. He brought a negligence claim against Mr Jones, arguing the valuation was significantly too low.

At first instance, the High Court dismissed the claim. Here’s why.

The Two-Stage Test for Valuer Negligence

To succeed in a claim against a professional valuer, the claimant must satisfy two key legal tests:

1. The Bolam Test
    The claimant must show that the valuer failed to act with the skill and care expected of a competent professional. This involves assessing whether the valuer’s approach aligned with accepted professional standards.
2. The Bracket Test
    The claimant must also show that the valuation fell outside an acceptable margin of error- the range within which competent professionals might reasonably differ.

Both elements must be proven. It’s not enough to show the valuation was low; the claimant must also demonstrate that the valuer’s method was professionally flawed and the result was outside the reasonable bracket.

Where the Claim Faltered

The issue in Bratt v Jones was that Mr Bratt’s expert had not been asked to comment on what margin of error would be reasonable. While the expert provided a higher valuation, they didn’t address the second part of the test—the bracket.

In contrast, the defendant’s expert told the court that a ±15% margin was appropriate for this type of valuation. With no competing evidence, the judge accepted that bracket and found the likely value to be £4.746 million. Mr Jones’s valuation was 14.15% below that - comfortably within the acceptable range. The claim failed.

Court of Appeal’s Findings

Mr Bratt appealed the decision, but the Court of Appeal upheld the High Court’s ruling, confirming that:

• The margin of error is a matter of evidence, not a fixed legal rule.
• A valuation outside the bracket may suggest negligence, but it’s not conclusive.
• A successful claim must include evidence on both the applicable professional standard and the appropriate bracket.

Why Clear Expert Instructions Matter

While the case didn’t turn solely on how the expert was instructed, it clearly shows why thorough and well-considered instructions are vital.

To give your case the best chance in valuation-based negligence claims, don’t just ask your expert for a new valuation. Ask them to explain:

• What range of values would be considered reasonable for the asset in question?
• Whether the original valuer’s approach fell below accepted professional standards.

By asking these questions, you ensure your expert is properly equipped to fulfil their duty to the court and address the issues the judge must decide.

Conclusion

Bratt v Jones demonstrates that success in valuation-based negligence claims depends on meeting both parts of the legal test with solid, relevant evidence. It’s not enough to simply disagree with a valuation - you must show that the professional breached their duty and that the result was outside the ordinary margin of error.

Thoughtful, complete expert instructions can make all the difference. Helping your expert address the specific issues the court will consider ensures your argument is given the attention it deserves.

Legal disclaimer

The matters contained within this article are intended to be for general information purposes only. This blog does not constitute legal advice, nor is it a complete or authoritative statement of the law in England and Wales and should not be treated as such.

Whilst every effort is made to ensure that the information is correct, no warranty, either express or implied, is given as to its’ accuracy, and no liability is accepted for any errors or omissions.

Before acting on any of the information contained herein, expert advice should always be sought.

© Melissa Worth, October 2025