Independent reports and retrospective valuations: the evidence a surveyor claim runs on

A claim against a surveyor is won or lost on two questions of expert opinion: should the defect have been found, and what was the property actually worth with it. Everything else — the survey, the quotes, the correspondence — is material for the experts to work from. This guide explains the two reports, and what to do before you commission either.

First, preserve the evidence

Repairs destroy evidence. Before any work beyond emergency measures:

• Photograph the defect thoroughly, with something for scale and with wider shots showing where in the property it is. Date the photographs (most phones do this automatically; keep the originals).
• Keep samples of failed materials where practical — a section of rotten timber, degraded roofing felt, a piece of cracked drain — bagged and labelled.
• Do not decorate over damp or cracking until it has been recorded and, ideally, seen by an independent surveyor.
• Keep the original survey report, terms of engagement, and every email with the surveyor's firm.
• Note the chronology now: when you first noticed anything, what you did, who you called, what they said.

If urgent work cannot wait, tell the surveyor's firm in writing that you are carrying it out, invite them to inspect first, and record everything you can. A court will understand that a collapsing ceiling had to be dealt with; it will be less sympathetic to a claimant who re-roofed the house and then complained.

The independent surveyor's report

This is sometimes called a negligence report or a liability report. It should be written by a chartered surveyor (MRICS or FRICS), ideally one with experience of giving expert evidence, and it should address, in terms:

1. What level of survey was undertaken, and what that level required under the RICS Home Survey Standard (or the standard in force at the time).
2. Whether the defect was present at the date of the survey, and the evidence for that view — the age and condition of materials, the pattern of decay, contemporaneous photographs.
3. Whether the defect, or signs of it, were visible within the scope of that survey, and what a reasonably competent surveyor would have seen and reported.
4. What the report should have said: the condition rating, the warning, the recommendation for further investigation.
5. What the reasonable buyer would have done with that information — negotiated, investigated further, or withdrawn.

The report should be balanced. A surveyor who overstates the case will be exposed by the insurer's expert, and the credibility of your whole claim goes with it. A good expert will tell you where the surveyor's scope defence has force.

The retrospective valuation

The measure of loss is the diminution in value at the date of purchase — explained in the guide on damages. To fix it, a valuer must assess two figures as at the purchase date: the value of the property as the survey described it, and its value with the defect known. The difference is the loss.

This is a specialist exercise. The valuer needs the market evidence for that date — comparable sales, the state of the local market, what buyers were doing about that kind of defect — and needs to explain how a buyer would have priced the risk. Repair quotes are an input, not the answer. The valuer should be a chartered surveyor with residential valuation experience in the area, and should be told clearly that the valuation is for use in a professional negligence claim.

Sometimes the same expert can address both liability and valuation; often it is better to separate them, because the skills differ.

How experts are instructed

At the complaint stage you can instruct whoever you like, and the reports are yours. Once a claim is under the Professional Negligence Pre-Action Protocol or in proceedings, expert evidence is governed by CPR Part 35: the expert's duty is to the court, not to you; the report must be in a prescribed form with a statement of truth; and the court controls what expert evidence is allowed. On the fast and intermediate tracks the court will often require a single joint expert instructed by both sides.

For that reason, many solicitors prefer to instruct the liability expert themselves, on agreed instructions, so that the report can be used in proceedings without being redone. A preliminary opinion — a short letter of advice on the merits — is often obtained first, at lower cost, before committing to a full report.

Costs vary widely with the property and the complexity; ask for a fixed quote and confirm what is included. If you succeed, reasonable expert fees are generally recoverable as part of your costs on the fast, intermediate and multi-tracks, subject to the fixed recoverable costs regime where it applies.

Getting the surveyor's own file

The surveyor's inspection notes, photographs and moisture readings can be decisive, and there are two ways to obtain them: a subject access request under the UK GDPR for the personal data the firm holds about you, which will usually include the survey file; and, once a claim is under way, pre-action disclosure under the protocol and CPR 31.16. Ask early and in writing.

What a solicitor will want from you

• Your photographs and chronology, and any samples kept.
• Any reports already obtained, with the instructions given to their authors.
• The original survey, terms of engagement and the firm's correspondence.
• Repair quotes and invoices.
• Purchase price, completion date, and the original marketing particulars and photographs if you have them.

This guide is general information about the law of England and Wales. It is not legal advice. CasePoint does not cover personal injury, including injury caused by a building defect.