Before you can start building your ADU, you will need a building permit from Placer County. If you are the homeowner, your builder will usually complete the permit process for you.

Prepare items like your site plan, floor plan, etc. The County will provide you with a submittal checklist in preparation for applying for your building permit. The application will be reviewed by the following departments at Placer County:

  • Planning
  • Environmental engineering
  • Environmental health
  • Engineering
  • Fire
  • Building

If the application is submitted completely with all the required documents, the review process should not take more than 8 weeks. After the permit has been issued, you pay the required fees depending on the square footage of your ADU. Once paid, you can pick up your permit and start building. 

Learn more or apply for your permits here through our e-services portal.

ADU flow chart graphic