The Bolam test, drawn from Bolam v Friern Hospital Management Committee [1957] 1 WLR 582, sets the standard of care for any professional exercising a special skill. A defendant is not negligent if their conduct accords with a practice accepted as proper by a responsible body of opinion skilled in that art. For RICS-regulated surveyors and valuers, the responsible body is identified largely by reference to the published standards of the Royal Institution of Chartered Surveyors. Courts treat the RICS Red Book (formally the RICS Valuation – Global Standards), the RICS Home Survey Standard and the RICS Rules of Conduct as primary evidence of what a competent surveyor should have done.
The Red Book is mandatory for RICS members carrying out valuations within its scope. It prescribes the basis of value, the assumptions, the inspection requirements and the reporting format. A material departure from the Red Book is not, on its own, conclusive of negligence, but it shifts the evidential weight. A surveyor who has followed the Red Book methodology, recorded comparables and stated assumptions clearly will usually find it easier to assemble the responsible body of opinion the Bolam defence requires. A surveyor who has not will need to explain why the departure was reasonable.
Valuation is an opinion, not an arithmetic answer. The leading authority is Singer & Friedlander Ltd v John D Wood & Co [1977] 2 EGLR 84, in which Watkins J accepted that a competent valuer could properly arrive at a figure within a bracket either side of the “correct” value. The customary brackets used by the courts are broadly:
Those figures are guidance, not a tariff. In Goldstein v Levy Gee [2003] EWHC 1574 (Ch) the court reviewed the bracket approach in detail and reminded practitioners that the margin reflects the inherent uncertainty of valuation rather than a tolerance for sloppy work. A figure inside the bracket may still be negligent if the underlying methodology was flawed.
Suppose a surveyor values a city-centre flat at £450,000. Applying the Singer & Friedlander 10 per cent margin for a property of that type, the competent range is roughly £405,000 to £495,000. Two expert surveyors disagree on whether £450,000 was within range on the inspection date. Under Bolam, the defendant escapes liability if a responsible body of valuation opinion supports the figure within an acceptable margin, even if other competent valuers would have arrived at a different number. The court will look at the comparables used, the assumptions recorded and the way the Red Book methodology was applied before deciding which body of opinion to prefer. This example is illustrative; every claim turns on its own facts.
Establishing that a surveyor fell outside the responsible body of opinion is only the first step. Damages are then filtered through the scope-of-duty rule from South Australia Asset Management Corporation v York Montague Ltd [1997] AC 191 (SAAMCO), reaffirmed and refined in Manchester Building Society v Grant Thornton [2021] UKSC 20 and Hughes-Holland v BPE Solicitors [2017] UKSC 21. A valuer giving information typically carries only the consequences of that information being wrong, not the full loss of the transaction. A Bolam-failing valuation may still result in modest damages if the lender or purchaser would have lost money in any event.
For Level 1, 2 and 3 home surveys, the RICS Home Survey Standard plays the same evidential role as the Red Book does for valuations. It sets out the inspection extent, the reporting style and the limits of each level. A Level 2 surveyor who fails to flag a defect visible on a non-invasive inspection, or a Level 3 surveyor who overlooks an issue a more intrusive examination should have caught, will be judged against the relevant chapter. Recent disputes around fire safety, external wall systems and cladding investigations have highlighted the importance of recording the limits of inspection clearly. Reports that set out what was not, and could not, be inspected tend to fare better under Bolam scrutiny than those silent on scope.
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