PROPERTY TERMS & CONCEPTS · 6 MIN READ

Coinsurance Math, Blanket Limits, and Reporting Forms

Coinsurance is the property exam's most reliable math question. The clause requires the insured to carry a limit equal to at least a stated percentage — most commonly 80 percent, with 90 and 100 percent also filed — of the property's value at the time of loss. If the insured falls short, recovery on a partial loss is penalized by the formula: (limit carried divided by limit required) times the loss, minus the deductible. Work one example cold: a $1,000,000 building insured for $600,000 with 80 percent coinsurance requires $800,000 of coverage; a $200,000 loss recovers 600/800 of it, or $150,000. The Agreed Value optional coverage is the escape hatch — the insured files a Statement of Values, the insurer accepts a limit, and the coinsurance condition is suspended for the period. If the option is never activated, the penalty applies in full. Several endorsements manage the relationship between limits and fluctuating or growing values. The Inflation Guard endorsement automatically increases the building limit by an annual percentage, applied pro rata through the term: with a 6 percent factor and a loss nine months in, the limit has grown 4.5 percent, so a $1,000,000 limit stands at $1,045,000 at loss. The Peak Season endorsement (CP 12 30) raises the business personal property limit during scheduled date ranges to track seasonal inventory buildup — the retailer whose stock triples before the holidays needs peak season, not inflation guard. The Value Reporting Form (CP 13 10) is for continuously fluctuating values: the insured files periodic value reports and premium follows actual exposure, but the discipline is severe. Miss a required report and the report-default penalty caps recovery at the value shown on the last report on file, no matter how large actual values had grown by the loss date. Specific insurance assigns a dedicated limit to each building or location; blanket insurance covers multiple locations or items under one combined limit, giving flexibility when values shift among sites. The insurer's defense against a blanket insured concentrating recovery at one underreported location is the Margin Clause (CP 12 32), which caps recovery at any single location to a percentage — commonly 110 or 125 percent — of that location's value on the most recent Statement of Values. Together, these tools reward accurate value reporting and punish underinsurance from every angle.