A Canadian business that renews its commercial property policy year after year without updating its insured value can be in for an unpleasant surprise after a loss. What is a co-insurance clause on a commercial property policy? It is a condition, common across many commercial property forms in Canada, that ties how much of a claim gets paid to how closely the insured amount matches a required share of the property's full replacement cost.
The clause rarely comes up until construction costs rise faster than a policy limit does, or a business owner has not reviewed a stated value since the building was purchased. By the time a fire, a burst pipe, or a storm causes damage, it is too late to adjust the amount of insurance carried for that loss.
This article looks at what a co-insurance clause generally means, how the underlying formula works, why insurers build it into commercial property forms, and where a business is most likely to run into it.
What Is a Co-Insurance Clause?
A co-insurance clause is a condition in many commercial property insurance policies in Canada that requires a business to insure its building or contents to at least a specified percentage of full replacement cost, most commonly 80 percent or 90 percent, and that is generally designed to reduce a partial-loss payment on a proportional basis when the amount carried falls short of that requirement.
The clause is not a separate coverage or an add-on. It is a mechanical condition sitting inside a commercial property form, and it applies automatically once the required percentage is not met, whether or not the shortfall was intentional.
How the Co-Insurance Formula Generally Works
Most commercial property forms in Canada use a version of the same calculation: the amount of insurance actually carried, divided by the amount required under the co-insurance percentage, multiplied by the amount of the loss. The result is generally treated as the payment amount before the deductible and policy limit are applied.
A simplified example illustrates the mechanics. A building with a replacement cost of $1,000,000 carries an 80 percent co-insurance requirement, meaning $800,000 of insurance is required. If the business instead insures the building for only $600,000, it has met 75 percent of the requirement. A $200,000 partial loss under that scenario would generally be calculated at 75 percent, or $150,000, before the deductible, leaving the business to absorb the remaining $50,000 out of pocket.
| Scenario | Insurance carried | Insurance required (80%) | Ratio met | $200,000 loss, before deductible |
|---|---|---|---|---|
| Fully insured | $800,000 | $800,000 | 100% | Typically paid in full |
| Underinsured | $600,000 | $800,000 | 75% | Typically prorated to about $150,000 |
| Significantly underinsured | $400,000 | $800,000 | 50% | Typically prorated to about $100,000 |
Coverage terms vary by insurer and by the specific wording on a given policy, so this table is a general illustration rather than a description of any one policy. Only the actual policy wording and a licensed broker can confirm how a co-insurance calculation would apply to a specific building and a specific claim.
Common Co-Insurance Percentages and Why Insurers Use Them
Commercial property forms commonly set the requirement at 80, 90, or occasionally 100 percent of replacement cost, and the exact figure is generally chosen by the insurer based on the class of business, the construction type, and how the risk is underwritten. A higher required percentage generally reflects an expectation that most losses on that class of property tend to be partial rather than total.
Insurers generally build the clause in for pricing fairness. Premiums are priced against the amount of insurance purchased relative to what a genuine full loss would cost to rebuild. A business that insures only a fraction of a property's true value while paying a correspondingly lower premium would otherwise be positioned to collect a full payment on smaller, more frequent partial losses, which shifts cost onto policyholders who report accurate values.
How a Stated or Agreed Value Endorsement Can Suspend Co-Insurance
A stated value or agreed value endorsement is a common way commercial property insurers suspend the co-insurance calculation for the policy term. Under this kind of endorsement, the insurer and the business agree in advance on a specific insured value, and the co-insurance formula is generally set aside as long as the amount carried stays at or above that agreed figure.
Getting to an agreed value usually starts with a professional replacement cost appraisal or a documented construction cost estimate, since insurers generally want that figure to reflect current rebuilding costs rather than purchase price or market value. Reviewing that figure at each renewal, particularly during periods of rising construction costs, is a common way businesses keep the agreed amount from drifting out of date.
Benefits of Understanding a Co-Insurance Clause
Knowing how a co-insurance clause works helps a business ask better questions at renewal rather than after a loss. A business that understands the formula is better positioned to review whether its stated insured amount still reflects current rebuilding costs, to ask a broker whether a stated or agreed value endorsement fits its property, and to budget for the premium difference that comes with insuring closer to full replacement cost. That kind of review tends to prevent the kind of shortfall that only becomes visible once a claim is already underway.
Where You'll Come Across a Co-Insurance Clause
A co-insurance clause tends to surface at predictable points in a business's insurance history: buying a commercial building for the first time, renewing a policy after several years of rising construction costs, adding a new location to an existing schedule, or working through a claim adjustment after a fire or water damage loss reveals the insured amount was set too low. It also comes up when a business commissions a replacement cost appraisal for financing purposes and discovers the figure differs meaningfully from what the current policy lists.
Talk to a Licensed Broker About Commercial Property Values
A co-insurance clause rewards accurate reporting and can penalize a value that has drifted out of date, which makes it worth reviewing before a loss rather than during one. A broker can walk through how a co-insurance requirement applies to a business's business insurance in Canada, including how it interacts with the property values carried under a commercial property insurance policy and what a business learned when it first read about what commercial property insurance typically includes. Get a commercial insurance quote to start that review with a licensed broker.
Coverage details vary by insurer and by policy, and only the wording of an actual policy and a licensed broker can confirm what applies to a specific situation.