Application, Permit Issuance and Inspection


Standard Plans have gone through the plan check process which reduces the time and money needed to get through the permitting process. We've updated the How To Apply for a Residential Building Permit form as well as the Construction Plan Checklist to reflect requirements for use of the Standard Plans. 

Importantly, there are some components of an application that cannot be pre-approved--these are site-specific and require work on the part of the applicant. Some components are required for all projects; some  components are required based on factors like location and site conditions. You will find the of universal requirements and relevant resources under the "Required For All Projects" button, and common requirements that don't apply in all cases under the "Required For Some Projects" button. Please contact a Permit Specialist at (707) 445-7245 to learn what reports from the "Required for Some Projects" list will be required for your ADU project: 

  1. Required for All Projects
  2. Required for Some Projects

Permit Issuance

Submit complete application package to the Humboldt County Planning and Building Department at 3015 H St Eureka, CA 95501. Plans, reports and forms will be reviewed for compliance with the Building and Zoning Codes. Instructions on how to achieve compliance will be provided. Clearances from other county departments and state agencies may be required.

Once all corrections have been made and all clearances have been obtained, the permit will be issued, and construction may commence.


During construction, your ADU will be inspected multiple times to ensure it is being built according to the permitted plans. In Humboldt County, for a traditional building permit, there are six inspection stages including:

  1. Foundation
  2. Floor
  3. Rough-out
  4. Insulation
  5. Drywall
  6. Final

Sometimes fire, water, or public works inspections are required as well. It is your and your builder’s responsibility to schedule all required inspections, which you can do leaving a message on the 24-hour voicemail for inspection requests at (707) 445-7244. 

While inspections are typically scheduled one week out, they are not conducted in all areas of the county each day of the week, so keep that in mind. Inspections also vary across projects, so contact the Building Division if you are unsure what inspections are needed and in what order. You will be issued a Certificate of Occupancy one week after your final inspection.