Most property policies - be they commercial, homeowners, condos or renters - generally do not cover damage caused by an earthquake. But the coverage can usually be added on as an endorsement or written as a separate policy altogether.
The cost of this coverage varies from state to state, and even by regions within states based on earthquake zones around known fault lines mapped by the U.S. Geological Survey (USGS). Generally, older buildings cost more to insure. Wood structures tend to get better rates than brick buildings because they tend to withstand quake stress better.
Because earthquake insurance is a type of catastrophic coverage, most policies carry a high deductible - anywhere from 2 to 20 percent of the replacement cost of the structure. So for example, if the replacement cost of your structure is $200,000, and your deductible is 5%, you would be responsible for the first $10,000 in damage, before the earthquake coverage would pick up the remainder, up to the policy limit.
The Earthquake coverage limit is usually written in an amount that matches your building limit for other perils.