Generally speaking interior work/actions do not involve any Zoning issues. It only becomes an issue if the proposed action changes the footprint of the building or outward appearance of a building in the Historic Overlay District. Some interior work, like bathrooms may require a Building Permit.
FAQ Topic: Building permits
The Village only issues Zoning Permits. Zoning Permits cover adherence to the provisions of the Village Zoning Law…Generally speaking use, footprint, and within the Historic Overlay District, the outward appearance and materials used. A Building Permit is issued by the County and makes sure the action is in adherence with the NYS Building and Fire … Continued
Building permits are issued by Jefferson County Code Enforcement