This is not an exhaustive or a complete subject. It is likely to change over time, with edits, additions and deletions, and is simply a collection of my thoughts based on many years of experience. You should follow your instincts, and you must always seek your own professional advice.
Why Careful Buildings Insurance Assessment Matters
Buildings insurance is often treated as an administrative afterthought — a figure is inserted when the property is purchased and then quietly index-linked each year. Yet the ‘sum insured’ represents the cost of completely rebuilding the property from scratch, not its market value. If that figure is wrong, the consequences can be serious. Underinsurance can trigger average clauses and materially reduce a claim payment; overinsurance results in years of unnecessary premium. Either way, complacency carries a cost.
Historic and Listed Buildings demand even greater care. Their reinstatement is rarely straightforward. Traditional materials, specialist skills and trades, regulatory oversight and extended rebuild periods can all increase the true cost of reconstruction. A timber-framed structure, crown post roof or lime-based construction may not increase the likelihood of a loss — but it can significantly increase the severity of one. For these properties in particular, a thoughtful and evidence-based approach to the sum insured is essential.
Buildings that been extended will also need to consider an increased sum-insured.
The Limits of Index-Linking
Most insurers apply annual index-linking to keep pace with construction inflation. While this is sensible in principle, index-linking is a blunt instrument. It faithfully preserves any error embedded in the original figure. If the starting point was too high, the excess compounds; if it was too low, the shortfall widens over time. Construction inflation is also volatile, particularly for heritage materials and skilled trades. Periodic review is therefore not a luxury — it is prudent risk management.
What Is a Reinstatement Cost Assessment (RCA)?
A Reinstatement Cost Assessment (RCA) is a professional appraisal of what it would cost to rebuild a property in its existing form, using appropriate materials and methods, following a total loss. Conducted in accordance with RICS guidance, an RCA measures the property accurately, assesses construction type, and applies elemental pricing rather than broad assumptions. It also allows for demolition, site clearance, professional fees and compliance with current Building Regulations and, where applicable, Listed Building Consent requirements.
Homeowners should consider commissioning a formal RCA when purchasing a complex or historic property, after significant alterations, or if the existing sum insured has not been professionally reviewed within the past four to five years. For higher-value, Grade I or Grade II* listed buildings, a three-to-five-year review cycle is often advisable. The modest cost of a proper assessment can prevent substantial financial exposure in the event of a major claim.
A Sensible Review Rhythm
For most properties, a formal reassessment every five years — supported by annual index-linking in between — is proportionate. For Listed or architecturally significant buildings, a slightly shorter cycle may be appropriate, particularly where rebuild values approach seven figures. The objective is not to chase perfection each year, but to ensure the insured value remains broadly aligned with real-world reinstatement costs.
Buildings insurance should not be guesswork. It is a technical assessment underpinning a significant financial safeguard. Periodic review, grounded in professional advice where necessary, provides confidence that the protection in place would genuinely respond if ever called upon.
If you would like to have an informal discussion about the insurance on your property, please contact me in confidence..: duncan@listedbuildingsurveys.co.uk
Disclaimer: Anything posted in this Blog is for general information only and it is not in any way intended to provide any advice, legal or otherwise, on any general or specific matter that you can rely on. You should always seek your own legal and surveying advice.