A Building permit is not required for the use of a portable generator only when it is intended to power a few appliances (refrigerator, fan, etc.) and a string of lights that are connected directly to the generator.  However, if you wish to connect a portable generator to the building's electrical system to power certain circuits, you must secure an electrical permit for the installation of a device that will allow you to do this safely.  Refer to the "Emergency Generator Checklist" (pdf) for detailed permit requirements for the installation of a transfer switch.  Warning portable generators must be stored indoors empty of fuel while not in use and must be placed outdoors while being used, 10' away from windows, doors and other openings to prevent exhaust fumes from getting inside the building.

To place and keep a generator permanently in an outside location a building permit is required.  Multiple county agencies regulate different aspects of its installation.  A permit application must include two sets of plans prepared by a design professional.  Multiple regulatory agencies will review the permit application for compliance with all codes and regulations applicable for the generator and its fuel source.  Refer to the "Emergency Generator Checklist" (pdf) for detailed permit requirements for an emergency generator.