Property insurance operates on a fundamental principle that distinguishes it from many other contractual relationships: the insurer's assessment of risk at the inception of the policy must remain substantially accurate throughout the policy period. When a policyholder changes how they use their property, they alter the very foundation upon which the insurer calculated premium, determined coverage limits, and decided to accept the risk in the first place. This principle, deeply embedded in both statutory insurance law and the common law of Canada, creates what professionals recognize as the notification obligation—a duty that, when breached, can transform an otherwise valid claim into a denied loss and leave a property owner facing catastrophic financial exposure.
The concept of material change traces its origins to the doctrine of utmost good faith, or uberrimae fidei, which has governed insurance contracts for centuries. Under this doctrine, both parties to an insurance contract owe each other a heightened duty of disclosure that exceeds what ordinary commercial relationships require. The insured must reveal all facts material to the risk, and this obligation does not expire once the policy is signed. Instead, it continues as an ongoing duty throughout the policy period, requiring the insured to notify the insurer whenever circumstances change in ways that might affect the insurer's willingness to continue coverage or the terms upon which that coverage is offered. Canadian courts have consistently upheld this principle, recognizing that an insurer cannot monitor every property it covers and must rely on policyholders to report changes that affect the risk profile.