Where it can be demonstrated that the mould or mildew arose directly from a sudden and unforeseen insured event, such as a burst pipe or water ingress, the claim would be considered on its individual merits. In those circumstances, the proximate cause of the damage would be the insured event (burst pipe or water ingress) rather than the mould or mildew itself.

Conversely, where there is no evidence of an insured event and the damage has developed gradually over time, the policy would not respond. Mould and mildew can gradually occur due to several issues including condensation, inadequate ventilation, rising damp or another maintenance issue.