the link you cite seems to be more about deliberate fires or disputes about the extent of damage rather than no permit.
Municipal-code enforcement can revoke occupancy per UBC 18.90.110 (.30) for avoiding building permits & safety inspection, but that hammer is rarely used, since political back lash, de-funding, and recall elections have resulted for far less.
I've witnessed clients cancelled over the phone, for leaky plumbing that watered the level below. No electrical, or permits required for drywall & paint.
It was the clients burden to challenge, but they just folded up tent and ran. Sold the uninsured house and moved into a condo insured by an association.
Another client works for an insurance underwriter, writing software that walks agents thru the claims investigation by phone. All the legal options available to insurance are not known by me, but I believe it includes both building codes, local laws, and insurance code.
The
Cancellation & Non-Renewal book only points to Insurance Code in my State, specifically using the language "
shall not increase hazards insured against".
If an owner is challenging insurance cancellation in court, proving an "
increased hazard" under the Insurance Code should require insurance to show clear safety violations. Missing safety inspections may allow "increase hazards", but weather that meets the statute without physical evidence of fire hazards, or code violations would be in the trial transcript. Searching such case precedents would require access to legal research databases.
However, if owners take insurance to court after using an unlicensed contractor, dumb enough to advertise in public domains, be found, and forced to appear, the court would certainly crucify the unlicensed idiot, and property owner.