Unit owners are typically required to obtain an insurance policy that covers damage to their units from the walls-in, as well as damage to adjacent units and/or the common areas for problems originating within their unit. This coverage is known as an HO-6 policy.
Owners who rent their units are required to carry landlord insurance, which is different from the HO-6 policy. Many associations require owners to provide evidence of insurance so that in the event of damages, the board can determine who is responsible and file insurance claims accordingly.
Proof of Insurance coverage is an issue that you may want to address in your Rules & Regulations.