At claim time, an under-insured asset can leave a lender exposed. A Bristol retail parade received an RICS mortgage valuation of £1.85 million in 2024. Its insurance rebuild cost, calculated from Building Cost Information Service benchmarks for the property type and local construction rates, was £2.4 million. The credit file recorded market value, while buildings insurance was set at £1.6 million. Each figure was valid in isolation. Together, they left the lender holding materially inadequate insurance.
Two Figures, Two Purposes
Market value and reinstatement cost answer different questions. Confusing them remains a persistent source of credit risk in UK commercial lending.
RICS Valuation Professional Standards defines market value as the estimated amount for which an asset should exchange on the valuation date between a willing buyer and willing seller in an arm's length transaction, after proper marketing, with both parties acting knowledgeably, prudently, and without compulsion. It reflects the investment market's view of income stream, location, tenure, and condition. Where land values are high relative to construction costs, market value may greatly exceed the cost of rebuilding the physical structure.
Reinstatement cost addresses another question: what would it cost to rebuild the building to the same specification if fire destroyed it tomorrow? The calculation draws on construction cost benchmarks, typically BCIS data, adjusted for property type, size, specification, location, professional fees, and demolition costs associated with a major rebuild. It has almost no mechanical link to market value. A single-storey industrial unit in an East Midlands employment zone may cost more to reinstate than its market value. A Central London office may have a market value three to four times its reinstatement cost, with land value and income yield making up a substantial share of the total.
The Insurance Adequacy Problem
UK mortgage conditions invariably make adequate buildings insurance a loan condition. In legal and practical terms, adequate insurance covers the structure's reinstatement cost, not its market value. A sum insured based on market value may overpay in some cases and underpay in others. It may also activate average clauses after a partial loss, reducing the insurer's payout in proportion to the under-insurance.
The mistake is most common in two situations. First, the credit file adopts the market value from the RICS report as the default insurance adequacy figure. Where the surveyor was instructed to provide market value only, no reinstatement figure appears in the file. Insurance is then based on a figure that is almost certainly unsuitable.
Second, the RICS instruction asks for both figures, but the reviewing credit officer transfers the market value line into the insurance section without separating the two. Red Book reports place the figures in different sections. Without familiarity with that structure, this error is easy to make.
Why RICS Reports Do Not Always Cover Both
The RICS Red Book does not automatically require every instruction to include both market value and reinstatement cost. The instruction letter determines the scope. If a lender's standard template requests market value only for LTV calculation, the surveyor supplies market value only. The report can comply with the Red Book while the credit file remains incomplete for insurance purposes.
The underlying issue is usually the instruction, not the surveyor. Templates written before rigorous insurance adequacy requirements entered credit policy may never have requested a reinstatement figure. Revising the template is the root fix. Until then, credit officers must check whether the report contains both figures and whether the borrower's insurance has been arranged against the correct one.
A similar gap can occur when the borrower's solicitor commissions the valuation rather than the lender. The scope may then be set without direct input from the lender's credit team. The report may include reinstatement cost or omit it, leaving the lender with only part of the information required by credit policy.
Where Desktop Estimates Help
A desktop appraisal tool like Finvise can surface both figures together by default for every property. They rely on different evidence bases, but a structured desktop process can estimate market value and reinstatement cost from public data without a separate instruction.
The reinstatement component matches BCIS cost tables to the property's use class, approximate floor area, and postcode district construction cost zone. It is an estimate, not a quantity surveyor's formal assessment. Unusual specification or substantial refurbishment complexity calls for a formal reinstatement cost assessment from a chartered building surveyor or quantity surveyor. For standard commercial assets, however, a BCIS-based estimate offers a defensible starting point and is significantly more reliable than using market value as a proxy.
Desktop estimates do not replace a qualified surveyor's role in setting final reinstatement cost figures for buildings insurance. They carry neither the professional liability nor the review standard of a formal RICS instruction. Their value is as an early check, allowing the credit team to test, before the application progresses, whether the borrower's proposed insurance figure plausibly relates to rebuild cost. A sum insured materially below the desktop reinstatement estimate warrants a question before completion, not after.
Building Both into the Credit File
Each commercial credit file should document the source of both the market value used for LTV calculation and the reinstatement cost used to test insurance adequacy. Sources may include an RICS Red Book report covering both, a separate reinstatement cost assessment, or a documented desktop estimate with suitable caveats about its preliminary status.
A file containing only market value, alongside an insurance sum insured set to a nearby round number, has a documentation gap worth closing. This does not mean the loan will necessarily encounter a problem. If one arises, however, the gap becomes part of the regulatory and litigation record. Where market value and reinstatement cost are likely to diverge, the credit officer should confirm the figure against which the borrower's insurance was set and record that confirmation. It takes one line in the credit note and is among the most straightforward file-level risk controls.
The two-figure check also identifies over-insurance. A high-value central London site with a market value of £4 million and reinstatement cost of £1.2 million should not carry £4 million of insurance. The borrower would pay significantly more for cover that the insurer would never fully pay in a total loss. Showing both figures in the desktop report gives the credit team a basis for discussing what adequate insurance means for that particular asset.
Independent data for commercial lending
Finvise provides desktop appraisals separating market value, reinstatement cost, and comparable evidence in one report.
Request Access