ACCESSORY DWELLING UNIT (ADU)/JUNIOR ADU (JADU) PERMIT PROCESS  

What is an ADU or JADU?

An ADU is an attached or detached residential dwelling unit that provides complete independent living facilities for one or more persons and is located on a lot with a proposed or existing single family dwelling (SFD) or multifamily dwelling (MFD).  It includes permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the SFD or MFD. 

A JADU is a unit that is no more than 500 square feet in size and contained entirely within a SFD.  A JADU may include separate sanitation facilities or may share sanitation facilities with the existing structure.

What is the permitting process for an ADU or JADU?

On January 1, 2020, new State ADU and JADU laws (Government Code section 65852.2 and 65852.22) went into effect and caused the County's Inland Area ADU ordinances to become null and void.  Until the County adopts new ADU ordinances, the County must process ADU and JADU applications pursuant to the new State laws.  

The County has implemented a streamlined, interim permit process for ADUs and JADUs.  This process will remain in effect until the County adopts new ADU ordinances.  ADUs and JADUs now require building permits only (no planning permits or Exemptions).  To begin, an applicant must submit a complete building permit application to the Building and Safety Division (B&S).  Please see the Supplemental Application Submittal Requirements for a building permit application and other information and materials required for a complete submittal.  

During the plan check review, B&S will review the application for compliance with the Building Code.  The Development Review Division will concurrently review the application for compliance with the new State laws using the applicable ADU or JADU checklist shown below. 

ADU/JADU Building Permit Process Flowchart

Please see the Building Permit Process Flowchart, for a step-by-step guide to the new ADU/JADU permit process.  

ADU - Process Flowchart

What standards apply to ADUs and JADUs?

Until the County adopts new ADU ordinances, only the standards specified in the new State laws (GC § 65852.2 and 65852.22) apply to ADUs and JADUs in the Inland Area.  Please see the checklists below for the standards that apply to each type of ADU and JADU.  

  • ADU Checklist A - One ADU per lot located within  (1) a SFD or accessory structure, and (2) a residential mixed use zone.
  • ADU Checklist B - One "small" detached, new construction ADU (i.e., subject to an 800 square-foot size limit and 16-foot height limit) per lot with a SFD and located within a residential or mixed use zone.  A "small" detached, new construction ADU may be located on the same lot as a JADU that meets the requirements of the JADU Checklist below, below.
  • ADU Checklist C - One or more detached ADUs located within (1) MFD structure, and (2) a residential or mixed use zone.
  • ADU Checklist D - Up to two detached ADUs per lot with a MFD and located within a residential or mixed use zone.
  • ADU Checklist E - One ADU per lot located (1) entirely within a SFD, MFD, or accessory structure, and (2) within a zone where SFD or MFD use is allowed.
  • ADU Checklist F - One new, attached ADU per lot with a SFD or MFD and located within a zone where SFD or MFD use is allowed.
  • ADU Checklist G - ONe new detached ADU per lot with a SFD or MFD and located within a zone where SFD or MFD use is allowed.
  • JADU Checklist - One JADU per lot located within (1) a SFD, and (2) a residential or mixed use zone.  A JADU may be located on the same lot as a "small" detached, new construction ADU that meets the requirements of ADU Checklist B, above.

ADUs located within the Coastal Zone shall remain subject to the permit requirements and development standards of Article II Coastal Zoning Ordinance section 35-142 until the County adopts and the Coastal Commission certifies a new ADU ordinance.