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Index Linking Moves Your Sum Insured Without You Asking
Home policies adjust the sum insured automatically each year against construction and retail cost measures, which protects against underinsurance but is not a valuation of your house.
Most home policies raise the sum insured each year without being asked. The adjustment is automatic, it changes the premium, and it is not a valuation.
What the adjustment is tracking
Buildings cover is normally linked to a published index of construction costs, covering materials and labour. Contents cover is linked to a broader retail price measure.
The two move differently. Building costs can rise sharply while general prices are stable, because they respond to materials supply and trade availability rather than to consumer demand.
The insurer applies the index movement to the existing figure at renewal. Nothing about the specific property is examined in the process.
Why insurers do it automatically
Sums insured decay in real terms if left alone. A figure set several years ago buys progressively less reinstatement as costs rise, which produces underinsurance without any change by the householder.
Underinsurance is expensive for both sides. The insurer faces disputes and complaints, and the household faces a proportionate reduction in a settlement under the average clause.
Indexation is a cheap way to keep most policies roughly adequate. It removes the commonest cause of a shortfall without requiring anyone to reassess anything.
What indexation does not do
An index cannot know that a house was extended, a loft converted or a kitchen replaced. Those changes alter rebuild cost by amounts no general measure captures.
Nor does it correct a figure that was wrong at the start. Applying an increase to an inadequate sum insured produces a slightly less inadequate one.
Contents indexation has the same limitation in the other direction. A household that has accumulated jewellery or equipment moves outside the index and outside single-article limits at once.
The premium effect and the temptation it creates
Because the sum insured rises, the premium rises with it even where nothing has been claimed. That increase is often mistaken for a general rate rise.
Reducing the sum insured to hold the premium down reverses the protection deliberately. It is a decision to accept a proportionate reduction in any future settlement.
Where a sum insured genuinely looks excessive, the correct response is a rebuild cost assessment rather than an arbitrary reduction at renewal.
Reading the renewal for it
Renewal documents state the previous and current sums insured, and usually name the index applied. Comparing the two figures shows whether indexation or repricing drove the change.
Some policies offer full reinstatement without a stated sum insured, replacing indexation with underwriting questions about size, age and construction. The exposure moves to the accuracy of those answers.
Indexation methods, indices used and average clause provisions vary by insurer and jurisdiction and change over time. The schedule in force governs the figures that apply.
Questions readers ask
Does the wind speed have to be recorded at my house?
No, and it rarely is. Insurers use the nearest available station, which is why local variation is a reasonable point to raise.
Are fences ever covered for storm?
Sometimes, on wider policies or as an add-on, but the standard position across many markets is that storm damage to fences is excluded.
