Glossary

Causes of loss form

The part of a commercial property policy that lists which perils are covered, offered in basic, broad and special versions of increasing breadth.

Also called: causes of loss, causes of loss basic broad special, CP 10 10, CP 10 20, CP 10 30

A commercial property policy pairs a coverage form, such as ISO CP 00 10 for buildings and business personal property, with a causes of loss form. The coverage form says what property is insured; the causes of loss form says what can damage it. ISO offers three: CP 10 10 Basic, CP 10 20 Broad and CP 10 30 Special.

Basic is a named-perils list: fire, lightning, explosion, windstorm or hail, smoke, aircraft or vehicles, riot or civil commotion, vandalism, sprinkler leakage, sinkhole collapse and volcanic action. Broad adds falling objects, weight of snow, ice or sleet, and water damage. Special insures direct physical loss unless the form excludes or limits it, so the exclusions define the coverage. Flood, earth movement, wear and tear, neglect and most mold sit outside, and theft of items such as furs and jewelry carries special limits.

Special is what most lenders and commercial leases require, and it puts the burden on the insurer to prove an exclusion applies. Basic and Broad cost less but leave gaps that surprise owners, such as damage from a cause that just isn't on the list. Carrier proprietary forms differ from ISO, so read the exclusions before the perils. The guide on causes of loss forms compares the three with examples, and concurrent causation explains what happens when a covered and an excluded peril combine.

Last reviewed October 10, 2026

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Related terms

Named perils Property coverage that pays only for losses caused by perils the policy lists, such as fire, lightning and windstorm; an unlisted cause is not covered. Special form (open perils) A property causes-of-loss form covering direct physical loss from any cause not specifically excluded or limited, rather than only the perils it lists. Exclusion A policy provision that removes coverage for specified perils, property, people or types of loss that the insuring agreement would otherwise include. Concurrent causation How a property loss is treated when a covered peril and an excluded peril combine to cause it, which court rules and policy wording answer differently. Vacancy clause A commercial property condition that removes or reduces coverage for certain losses once a building has been vacant more than 60 consecutive days.

Related guides

Anti-concurrent causation clauses: when one excluded cause sinks a claim How the lead-in to the ISO special form's big exclusions works, how California and Texas courts treat it, and what to do when wind and water hit one building. Basic, broad and special causes of loss forms: what each covers ISO's three causes of loss forms decide which perils your property policy pays for. Compare CP 10 10, CP 10 20 and CP 10 30 and see where claims diverge. Commercial package policies: when a BOP is too small A commercial package policy combines separate coverage parts under shared declarations and conditions. When values, locations or class outgrow a BOP. Commercial property insurance: what it covers and what it doesn't How the standard ISO commercial property policy works: covered property, causes of loss, built-in extensions and limits, valuation, and the gaps to close. What the COVID-19 business interruption lawsuits decided Courts mostly held COVID-19 closures were not direct physical loss under property policies. The key rulings, the exceptions, and what to check in your policy. How to read a commercial policy: declarations, forms and endorsements How a commercial policy is assembled, what to check on the declarations, why endorsements override the base form, and a reading order that catches problems.

Related en español

Seguro de propiedad comercial: qué cubre y qué no Cómo funciona la póliza ISO estándar de propiedad comercial: bienes cubiertos, causas de pérdida, extensiones y sus límites, valuación y los huecos por cerrar.