Extended coverage is a term used in the property insurance business.
[1] The endorsement has been largely supplanted by what is referred to as "basic" causes-of-loss form first introduced by Insurance Services Office in 1986 as part of its simplified language revisions.
The basic form includes most of the perils previously provided by fire and extended coverage and it adds vandalism and malicious mischief, sprinkler leakage damage, sinkhole collapse, and volcanic action.
Broad form adds three additional perils plus collapse due to certain causes.
Special form covers almost all risks of loss except those that are specifically excluded.