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Permit Requirements for Back-up Generators

generator permanently installedDuring a power de-energization event, a generator can provide emergency electrical power to your home. If you live in unincorporated Sonoma County and plan to use a generator that connects to your electrical panel, you will need to obtain a permit from Permit Sonoma for the electrical and plumbing work. If the generator will be housed in a structure of its own, the structure may be subject to additional permits.

Additional permits for generators may be required from the Northern Sonoma County Air Pollution Control District or the Bay Area Air Quality Management District.

If you plan to run your appliances directly off a portable generator (instead of through the electrical panel), you do not need a permit from the County.

Apply for a Generator Permit

Generator Permit Checklist

In order to obtain a generator permit, your permit submittal package shall include the following Construction Plans, uploaded as a single PDF file (instructions for combining PDF files):

  1. Make and Model of Generator
  2. Site plan (view detailed site plan requirements) including all required setbacks to property lines, combustibles, and vegetation; location of underground utilities
  3. Manufacturer's installation instructions and installation details
  4. Electrical single line diagram including wire size, indicate transfer switch or interlock, and indicate if the generator is a “separately derived system” (See Definition CEC Article 100 Chapter 1 for Separately derived system)

Apply via Permits Online

When applying for a generator permit via Permits Online, select the “New Building Permit with Plan Check” option.

Apply for Generator Permit