Court Clarifies Efficient Proximate Cause Rule: Covered Peril Must Be the Dominant Cause

A scenario all too familiar in the world of property insurance claims arises when an insured seeks a full roof replacement after their roof is beyond its useful life. The roof is visibly deteriorated, and a minor wind event becomes the proverbial “straw that breaks the camel’s back.” This raises a central coverage question: was the loss caused by a covered peril—wind—mandating payment for a new roof? Or, was the loss caused by excluded conditions—deterioration and wear and tear—which insurance does not cover? The answer to this question often determines whether the insurer owes tens of thousands of dollars, or nothing at all.

Recently, in Stella Property Development and Event Production, LLC v. Auto-Owners Insurance Company, 2026 WL 221489 (W.D. Pa. 2026), the United States District Court for the Western District of Pennsylvania addressed three issues that are often central to these types of claims:  Pennsylvania’s “causation” analysis, the scope of ensuing loss clauses, and the evidentiary threshold for maintaining statutory bad faith claims.

Following a windstorm, Stella submitted an insurance claim, alleging extensive roof damage. Auto-Owners had issued Stella a commercial property policy, covering a historic building formerly used as a church. As typical, the policy insured against “direct physical loss or damage” to the structure subject to various exclusions.

After multiple inspections, Auto-Owners concluded that the roof had not been damaged by a single wind event, but rather, was in a deteriorated state due to age, decay, and wear and tear. Accordingly, Auto-Owners denied coverage pursuant to the policy’s wear and tear and maintenance exclusions. Stella filed suit, asserting claims for breach of contract and statutory bad faith. The parties ultimately filed cross-motions for summary judgment, prompting a 32-page Memorandum Opinion.

 

Causation

The “entire premise” of Stella’s argument was that, even if the roof manifested wear and tear, the cited exclusions did not bar coverage under Pennsylvania’s “efficient proximate cause” rule. However, Stella also invoked what other jurisdictions refer to as the “concurrent causation” doctrine. Accordingly, prior to addressing Stella’s argument, the District Court clarified the difference between these theories.

“Efficient proximate cause” is framed in causal sequence, and asks which peril was the “triggering” cause. It requires coverage where a covered cause of loss “sets into motion the chain of events” culminating in the loss, even if excluded causes contributed along the way.

“Concurrent causation” is applied where covered and excluded perils operate as independent, concurrent causes of the same loss. It permits coverage so long as the covered peril is a “concurrent proximate cause of the injuries.”

The District Court then explained, regardless of labels, “courts often collapse the analysis into a single inquiry focused on identifying the proximate or predominant cause of the loss.”

Looking to Trexler Lumber Co. v. Allemannia Fire Ins. Co. of Pittsburgh for guidance, the District Court predicted that the Pennsylvania Supreme Court would apply the efficient proximate cause doctrine in a predominant-cause sense. Under that framework, Stella’s claim was not defeated merely because excluded perils contributed to the loss, but Stella was required to adduce evidence that the covered peril was the “dominant and efficient” cause of the damage, as opposed to merely a remote or incidental cause.

 

Ensuing Loss Clauses

The policy’s wear and tear and maintenance exclusions each contained ensuing loss provisions, albeit with slightly different wording. Despite the differing language, the District Court’s interpretation was consistent: the ensuing loss clauses applied only where the excluded condition itself “results in” a new, distinct covered peril. While inadequate maintenance and/or wear and tear may affect how a roof performs during a windstorm, neither “results in” a windstorm.

Accordingly, the District Court made clear that ensuing loss clauses are to be strictly construed, and do not automatically trigger coverage when excluded conditions contribute to the loss. Rather, coverage is only restored when the excluded conditions actually give rise to a separate covered peril.

 

Bad Faith Claim

Finally, because Auto-Owners’ coverage determination was grounded in a thorough investigation and well-supported expert opinions, Stella’s bad faith claim failed as a matter of law, and was dismissed.

In coming to its coverage decision, Auto-Owners’ relied on detailed investigative materials, multiple inspections, and expert assessments. Those findings all attributed the roof damage to decay, wear and tear, and inadequate maintenance, thereby providing Auto-Owners with an objectively reasonable basis for concluding that a covered windstorm was not the dominant and efficient cause of the loss.

 

Takeaway

This decision provides helpful framework as to how Pennsylvania courts are likely to assess causation in these claims, regardless of labels. Insurers should take heed of this as they adjust claims that involve multiple perils.


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