One Event Or Several: How Insurers Aggregate A Loss

A single storm damaging a roof, a fence and a car raises a question before any money moves: is this one loss or several? The answer changes the arithmetic.

Why aggregation matters

Excesses are deducted per claim or per occurrence. Treating damage as several events multiplies the deductions, while treating it as one applies them once.

Limits work in the opposite direction. A single limit applied to one aggregated event can cap a settlement that would have been paid in full as separate claims.

The policyholder's interest therefore depends on which side of the limit the loss falls, which is why the question is argued in both directions.

The tests insurers apply

Wordings commonly aggregate losses arising from one event, one occurrence, or one originating cause. Each phrase is progressively wider in what it draws together.

An event is usually understood as something happening at a particular time and place. Originating cause can reach much further, linking losses separated by months.

Some policies add an hours clause, aggregating everything arising from a named peril within a defined window, which is common for storm and flood.

Where the question bites hardest

Escape of water from a slow leak damaging several rooms over weeks tests whether the leak is one cause or each area of damage a separate loss.

A series of thefts from the same property, or repeated malicious damage, raises the same issue with a different peril.

On the motor side, a multi-vehicle collision can produce arguments about whether successive impacts are one occurrence for liability limit purposes.

Excesses across sections

A storm damaging both buildings and contents engages two sections of a home policy. Whether one excess or two applies depends on the wording, not on the event.

Better wordings state expressly that a single excess applies to one event across sections. Where they are silent, the schedule usually governs and two may be deducted.

This is worth checking at purchase, since it is the difference most often noticed and least often anticipated.

How the argument is resolved

Aggregation disputes turn on the precise words used and on how courts in the relevant jurisdiction have interpreted them, which varies considerably.

Evidence of timing and causation carries the argument: when the damage occurred, what caused each part, and whether a single chain links them.

Aggregation wordings, hours clauses and excess structures vary by insurer and jurisdiction and change over time. The wording and applicable case law determine the outcome.