1.2 Insurable Interest, Indemnity, and Other Insurance Principles
Key Takeaways
- For property/casualty, insurable interest must exist at the time of loss; without it the contract is a void wager.
- Indemnity restores the insured to the pre-loss position only; ACV = Replacement Cost − Depreciation, and replacement cost pays without depreciation subject to policy conditions.
- Coinsurance recovery = (Carried ÷ Required) × Loss; underinsuring triggers a penalty.
- Subrogation lets the insurer recover from a negligent third party and prevents the insured from double-recovering.
- Utmost good faith governs representations, warranties, and concealment; a material misstatement can void coverage.
The Core Property/Casualty Principles
Five doctrines govern every property and casualty policy: insurable interest, indemnity, utmost good faith, subrogation, and contribution (other insurance). The national exam returns to these constantly because they decide how much an insurer pays and whether it pays at all.
Insurable Interest
An insured must suffer a genuine financial loss if the covered property is damaged. Without insurable interest, the contract is a wager and is void. Key timing rule for P&C: insurable interest must exist at the time of the loss (in life insurance it must exist only at policy inception — do not mix these up). A person can insure property they own, hold a mortgage on, lease, or are legally responsible for. A general creditor of the owner usually has no insurable interest in a specific item.
The Principle of Indemnity
Indemnity means the insured is restored to the same financial position held immediately before the loss — no better, no worse. You should not profit from a loss. Three valuation methods flow from this:
- Actual Cash Value (ACV) = Replacement Cost − Depreciation. This is the default for most property losses.
- Replacement Cost (RC) = the cost to repair/replace with like kind and quality, without deducting depreciation (subject to policy conditions, e.g., you must actually rebuild).
- Agreed/Stated Value = a figure set in advance, common for antiques, fine art, and collector autos.
Worked ACV Calculation
A roof costs $20,000 to replace new. Its useful life is 25 years and it is 10 years old at the time of a windstorm loss. Straight-line depreciation = 10/25 = 40 percent.
- Depreciation = $20,000 × 0.40 = $8,000
- ACV = $20,000 − $8,000 = $12,000
If the policy is written on an ACV basis with a $1,000 deductible, the insurer pays $12,000 − $1,000 = $11,000. On a replacement-cost basis (and assuming the roof is actually replaced and limits are adequate), the insurer would pay $20,000 − $1,000 = $19,000, with the depreciation holdback released after repairs are completed.
A 10-year-old roof with a 25-year life and a $20,000 replacement cost is destroyed. The ACV policy carries a $1,000 deductible. How much does the insurer pay?
Limits That Support Indemnity
Four devices keep recovery from exceeding actual loss:
| Device | Function |
|---|---|
| Deductible | Insured retains the first dollars; discourages small claims |
| Coinsurance | Penalizes underinsurance on property |
| Other-insurance / pro rata | Prevents collecting full limits from two policies |
| Subrogation | Stops a double recovery from insurer + negligent third party |
Coinsurance Worked Example
A commercial building worth $500,000 carries an 80 percent coinsurance clause, so the insured must carry at least $400,000. They actually carry only $300,000. A $100,000 fire occurs. The recovery = (Carried ÷ Required) × Loss − deductible = ($300,000 ÷ $400,000) × $100,000 = $75,000 (less any deductible). The $25,000 shortfall is the coinsurance penalty for underinsuring.
A building valued at $500,000 has an 80% coinsurance clause but is insured for only $300,000. A $100,000 loss occurs (ignore deductible). What does the insurer pay?
Utmost Good Faith, Subrogation, and Contribution
Utmost good faith (uberrimae fidei): both parties rely on each other's honesty. This produces representations (statements believed true), warranties (guaranteed true), and concealment (silence about a material fact). A material misstatement can void coverage.
Subrogation: after paying a claim, the insurer steps into the insured's legal shoes to recover from the at-fault third party. The insured may not impair this right (e.g., by signing a waiver after the loss).
Contribution / other insurance: when two policies cover the same loss, they share it — typically pro rata by limits or by equal shares — so the insured collects only the actual loss once.
Pro Rata Other-Insurance Worked Example
An insured carries two valid policies on the same warehouse: Policy A with a $300,000 limit and Policy B with a $100,000 limit, total $400,000 of coverage. A covered loss of $80,000 occurs. Each insurer pays its proportion of the total limits:
- Policy A share = ($300,000 ÷ $400,000) × $80,000 = $60,000
- Policy B share = ($100,000 ÷ $400,000) × $80,000 = $20,000
The insured collects exactly $80,000 once — never $160,000 — preserving indemnity. Subrogation works the same way against a negligent third party: if the insurer pays the $80,000 claim and then recovers $80,000 from the party that started the fire, any excess recovery beyond the insurer's payout (and the insured's deductible) belongs to the insured, again preventing profit.
Stated Value, Market Value, and Functional Replacement
The exam contrasts several valuation bases beyond ACV and replacement cost. Market value is what a willing buyer would pay — it includes land and demand, so it usually differs from rebuilding cost and is rarely the insuring basis for buildings. Functional replacement cost lets an insurer replace an obsolete component with a modern functional equivalent (replacing plaster walls with drywall) rather than identical materials. Agreed/stated value suspends coinsurance and fixes the payable amount up front, used for fine arts and collector autos where depreciation is hard to measure.
Choosing the wrong basis is a classic distractor: a building can have a high market value but a low replacement cost, or vice versa, depending on location and age.
Tie it back to indemnity: every valuation method exists to restore the insured to the pre-loss position without profit. ACV builds in depreciation; replacement cost releases the depreciation holdback only after the property is actually rebuilt; agreed value fixes the number to avoid disputes; and market value is generally rejected for buildings because it includes land and demand the policy never insured.