Supreme Court limits rebuilding guarantee in flood-damaged home insurance dispute

The Supreme Court of Canada has ruled that an Ontario couple’s guaranteed rebuilding cost coverage did not require their insurer to pay all the additional costs of meeting conservation authority requirements after a flood destroyed their home.

In Emond v. Trillium Mutual Insurance Co., 2026 SCC 3, seven judges upheld the policy’s exclusion for increased legal compliance costs, subject to a $10,000 exception. The January 30 judgment dismissed the homeowners’ appeal with costs. Trillium had accepted coverage for the flood loss; the dispute concerned how much of the rebuilding expense it had to cover.

Justice Rowe, writing for the majority, said the endorsement allowed recovery beyond the policy’s stated insurance amount but left the relevant exclusion intact. Justices Karakatsanis and Côté dissented separately, each favouring coverage for compliance with laws in force when the policy was last renewed, though they reached that result through different interpretations.

A rebuilding promise and a compliance exclusion

Stephen and Claudette Emond’s Ottawa River home was deemed a total loss after flooding in April 2019. Rebuilding required additional work to meet the Mississippi Valley Conservation Authority’s requirements. Their insurance included both water protection and a guaranteed rebuilding cost endorsement.

The base policy listed $585,092 in dwelling insurance. The rebuilding endorsement allowed eligible repair or replacement costs to exceed the stated insurance amount, provided its conditions were met. Those conditions included maintaining insurance at the insurer’s accepted estimate of the full rebuilding cost, accepting annual adjustments and reporting substantial physical changes.

Elsewhere, the policy excluded increased repair or replacement costs resulting from laws regulating zoning, demolition, repair or construction. A separate provision restored up to $10,000 of specified compliance coverage. The homeowners argued that the rebuilding guarantee displaced the exclusion and promised the full cost of rebuilding.

An Ontario Superior Court judge accepted their position. The Court of Appeal reversed that decision, leaving the compliance exclusion in place apart from the $10,000 exception. The Supreme Court majority upheld that result.

Majority read the policy as a whole

Rowe stressed that endorsements form part of the insurance contract and must be read with the underlying policy. Clear language governs when the contract, considered as a whole, has only one reasonable meaning. A competing interpretation does not establish ambiguity merely because a party advances it.

Here, the endorsement expressly amended the formula for calculating payment for damage to the house and left other policy provisions and liability limits unchanged. Its principal benefit was removing the upper dollar limit on eligible rebuilding costs. It did not insure additional property or additional perils, the majority said.

The homeowners relied on the endorsement’s title, its reference to “current building techniques” and the absence of the compliance exclusion from a separate list of exclusions accompanying the endorsements. Rowe rejected those arguments. The heading could not override the rest of the contract; contemporary construction methods were not the same thing as legal requirements; and the endorsement did not replace the base policy’s exclusions.

The majority also rejected the argument that only costs arising from laws enacted after the policy was issued or renewed were excluded. The comparison was between rebuilding the home as it previously stood without regard to legal requirements and rebuilding it in compliance with applicable law. The exclusion did not make the date a requirement took effect decisive.

Rowe added that the homeowners’ proposed interpretation would require insurers to assess regulatory compliance property by property, or accept liability for pre-existing non-compliance. He found no basis in the policy language or commercial context for that result. The dissenters disputed that assessment.

Protection against worthless coverage survives

The court also addressed the doctrine of nullification of coverage, which prevents an insurer from relying on a provision that would effectively defeat the purpose of the coverage purchased.

Rowe rejected Trillium’s argument that this protection applies only when policy language is ambiguous. He maintained the Ontario rule that even an unambiguous provision should not operate to make the relevant coverage worthless. The doctrine addresses an extreme situation in which an insurer collects a higher premium without taking on material risk.

That threshold was not met here. Even with compliance costs excluded, the endorsement still allowed the Emonds to recover eligible rebuilding costs exceeding the policy’s stated amount. Receiving less than they would have received without the exclusion did not eliminate that benefit.

Two dissenters found ambiguity

Karakatsanis agreed that the compliance exclusion applied to the rebuilding endorsement, but considered its reference to increased costs ambiguous. In her view, an ordinary purchaser could reasonably understand it to exclude only increases caused by laws introduced after the policy was issued or renewed.

She emphasized insurers’ ability to assess existing regulatory requirements when setting premiums and the consumer-protection purpose of home insurance. Nothing in the record, she said, showed that assessing compliance costs was more onerous than ordinary valuation. Her interpretation would leave insurers protected against legal changes that were unknowable when they agreed to the coverage.

Côté found a more fundamental ambiguity in the relationship between the endorsement and the base policy. She pointed to the rebuilding guarantee, the reference to current building techniques, and the omission of the compliance exclusion from both the endorsement itself and the accompanying list of exclusions. Those features could reasonably suggest broader coverage to an ordinary purchaser, she said.

Both dissenters would have allowed the appeal in part, covering compliance with laws already in force at the last renewal while excluding increased costs from later legal changes. Their position did not prevail. The majority’s result turns on this policy’s wording and preserves the distinction between a guarantee against a dollar limit and coverage for every category of rebuilding expense.

Read the Supreme Court of Canada’s reasons in Emond v. Trillium Mutual Insurance Co., 2026 SCC 3.