An unpermitted remodel can range from cosmetic work that never needed a permit to structural or trade work that did. The right response starts with separating those scopes instead of treating the entire remodel as one issue.
Building departments use their own terminology, deadlines and procedures. Treat this as a practical orientation and verify the current rule with the jurisdiction that issued — or would issue — the permit.
Not every remodel item requires a permit, so the first step is determining which parts of the work were regulated.
It can raise disclosure, lender, insurer or buyer questions. For transaction-specific advice, consult the appropriate real-estate, legal or insurance professional.