A

The window is considered to be real property and not personal property. Therefore, in answering this question we look at exclusion J (5), which excludes “that particular part of real property on which you or any contractors or subcontractors working directly or indirectly on your behalf are performing operations, if the 'property damage' arises out of those operations” (emphasis added).

You stated that the window had been installed and the trim was being nailed on as a separate operation. Given that scenario, the window trim was “that particular part” of real property that was being worked on at the time. With this interpretation, the trim would be excluded but the window pane covered. This is similar to a common example, used to explain this exclusion, of a plumber welding pipes. If the plumber's welding catches the pipes on fire and causes the house to burn down, the pipes are excluded but the house is covered.

The courts, however, have interpreted this phrase in different ways. Some courts might consider the entire window project — glass through trim — as one operation, still being worked on at the time of the loss. Using the continuous operation theory, damage to any part of the project would be excluded. However, since you consider the trim installation to be separate from the window installation, the property damage to the glass would be insured but the trim would be excluded.