What Is the 80% Rule for Home Insurance?

The 80% rule is adhered to by most insurance companies. According to the standard, an insurer will only cover the cost of damage to a house or property if the homeowner has purchased insurance coverage equal to at least 80% of the house's total replacement value. If the amount of coverage purchased is less than the minimum 80%, the insurance company will only reimburse the homeowner a proportionate amount of the required minimum coverage that should have been purchased.

Key Takeaways:

  • The 80% rule means that an insurer will only fully cover the cost of damage to a house if the owner has purchased insurance coverage equal to at least 80% of the house's total replacement value.
  • If the coverage is purchased covers less than 80% of the replacement value, the amount paid by the insurance company will be proportionate to the amount of coverage originally purchased.
  • Capital improvements and inflation affect the value of a property and the 80% rule.

How the 80% Rule Works for Home Insurance

For example, James owns a house with a replacement cost of $500,000, and his insurance coverage totals $395,000. An unanticipated flood causes $250,000 worth of damage to James' house. At first glance, you might assume since the amount of coverage is higher than the cost of the damage ($395,000 vs. $250,000), so the insurance company should reimburse the entire amount to James. However, because of the 80% rule, this is not necessarily the case.

According to the 80% rule, the minimum coverage that James should have purchased for his home is $400,000 ($500,000 x 80%). If that threshold had been met, any and all partial damages to James's home would be paid by the insurance company. However, since James did not buy the minimum amount of coverage, the insurance company will only pay for the proportion of the minimum coverage represented by the actual amount of insurance purchased ($395,000/$400,000), which amounts to 98.75% of the damages. Therefore, the insurance company would pay out $246,875 and, unfortunately, James would have to pay the remaining $3,125 himself.

Because improvements to a home and inflation affect home values, homeowners should review their insurance policies periodically to ensure their coverage meets the 80% rule.

How Capital Improvements Affect the 80% Rule

Since capital improvements increase the replacement value of a house, it is possible that coverage that would have been enough to meet the 80% rule before the improvements will no longer be sufficient after.

For example, let's say James realizes he did not purchase enough insurance to cover the 80% rule, so he purchases coverage that covers $400,000. One year passes, and James decides to build a new addition to his house, which raises the replacement value to $510,000. While the $400,000 would have been sufficient to cover the $500,000 house ($400,000/$500,000 = 80%), the capital improvement has driven up the replacement value of the house, and this coverage is no longer enough ($400,000/$510,000 = 78.43%). In this case, the insurance company will once again not fully compensate for the cost of any partial damages.

Inflation can also cause the replacement value of a house to increase. Therefore, homeowners should review their insurance policies and home replacement values periodically to see if they have adequate coverage to cover any damages fully.