Commercial overinsurance: making sense of a lower rebuild figure

Imagine a commercial property client receiving a rebuild cost assessment that puts the cost below the figure on their current policy. Their first reaction might be relief. Or it might be concern: does a lower figure mean less protection?

For the client, the concern is what a major loss could cost them. They want to know they have enough cover for rebuilding, without being left to fund a shortfall. That deserves more than a new number on a renewal schedule.

RebuildCostASSESSMENT.com's 2026 Property Insurance Infographic found that 23% of the commercial properties assessed were overinsured.

That finding gives brokers a useful starting point for a conversation about what supports the figure. When an assessment challenges a familiar number, the explanation matters.

A lower number needs context

A client may have carried the same starting figure through several renewals, with annual increases along the way. If a rebuild cost assessment comes back lower, they may wonder what has changed, or whether something has been missed.

The report is a useful place to start. It sets out an estimate of rebuild costs, based on the property details, date and assumptions used. Talking through those details helps explain how the figure was reached.

A lower result does not necessarily mean that building costs have fallen. The new report may use different information or include different costs. Any differences need to be clear before drawing conclusions about the old figure.

The policy basis matters too. RICS explains that, under day-one cover, the declared value reflects rebuild costs at the start of the policy. The sum insured also includes an allowance for inflation during the policy year and the time needed to rebuild. A useful comparison needs to account for what each figure includes.

We can explain the basis and limits of our assessment. The broker can check how it relates to the policy and raise any points with the insurer.

Making the value clear

If an inflated figure is increasing the premium, a review may identify an avoidable cost. Any effect on the premium needs to be checked with the insurer.

There is also value in helping the client understand what they are relying on. Someone who has chosen a higher figure out of caution may need reassurance that their concern about rebuilding has been taken seriously.

That calls for a conversation which leaves room for questions. The client can question details they do not recognise and flag changes to the property. The broker can help them understand how the assessment informs the insurance discussion, including anything that still needs an answer.

Where the FCA's insurance fair-value rules apply, they look at the total price, the benefits of the product and the services provided. A rebuild cost assessment supplies information about the building. It should be used as one source of evidence in that wider review, rather than treated as proof of compliance.

Confidence in the figure

For brokers, explaining a lower assessment is a chance to show the care behind the review. A client does not need to become an expert in rebuild costs. They should have a clear account of what the figure means and how it will be used.

The aim is to reach a figure supported by the building information and understood in the context of the policy. Whether it rises or falls, the reasoning deserves attention.

If your client's rebuilding figure needs a clearer basis, speak to RebuildCostASSESSMENT.com about the right assessment route. We can explain what information is needed and whether a new assessment would be suitable.