County of Sonoma
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Accessory Dwelling Units

ADUs and JADUs Without Permits

backyard accessory dwelling unit

Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs) constructed without permits may pose serious issues for homeowners, tenants, and neighbors.

Why should I permit my ADU or JADU?

  • Reduce the risks to the occupants. ADUs and JADUs that are constructed without permits may unknowingly present serious health and safety risks to the occupants.
  • Reduce liability. An illegal ADU or JADU would pose as a significant liability to the owner. For example, insurance may not cover damages if a fire started in the unit.
  • Increase your property value. Improve the potential for both the rental income and/or resale value by legalizing the ADU or JADU.
  • For your peace of mind. Legalizing your ADU can eliminate any worries about code enforcement actions against you.

What are my options?

Delayed Enforcement

The County's ADU Rescue program allows delayed enforcement against ADUs constructed without permits during an eligible time period:

  • Before October 14, 2021
  • January 1, 2023 - Before January 4, 2024
  • January 1, 2025 - Before January 8, 2026

This does not remove the need to eventually permit your unit but provides a relief period for units without  health and safety issues to keep occupants in their homes while permitting is in process.

Legalization

Pathways for permitting your unit depend on when it was created:

  • ADUs and JADUs created on or after January 1, 2020: See 9-4-19 Permits to Remove or Legalize Unpermitted Work for the general process and requirements. Pursuant to Government Code Section 66323, correction of nonconforming zoning conditions will not be required, but the structure will need to be brought up to compliance with other adopted codes.
  • ADUs and JADUs created prior to January 1, 2020: Read below!

ADUs and JADUs created without permits before 2020

New Permitting Opportunity

As of January 1, 2025, State law (AB 2533) provides a new pathway for permitting accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs) that were constructed without permits.

Pursuant to Government Code Section 66311.7 (formerly Section 66322), Permit Sonoma will not deny a permit for an existing ADU or JADU on an inland parcel that was constructed without permits before January 1, 2020, unless the building is considered substandard pursuant to Health and Safety Code Section 17920.3. Permit issuance will not be contingent on other standards for development, such as setbacks, size, and height restrictions.

How do I know if my ADU or JADU is substandard?

“Substandard” means any condition defined by California State Health and Safety Code Section 17920.3, which exists to an extent that it endangers the life, limb, property, safety or welfare of the public, nearby residents, or occupants.

Before preparing an application, homeowners may obtain a confidential third-party code inspection from a licensed contractor to determine the unit’s existing condition or potential scope of building improvements needed. This will not be considered a substitute for the required County site inspection as set forth in the permit process outlined below.

How do I permit my pre-2020 ADU or JADU?

The unit must meet the following eligibility criteria, and the property owner must follow the permit process outlined below.

Eligibility Criteria

Your ADU or JADU may be eligible for a permit if...

Permit Process
  1. Submit a Building Permit with Plan Check (BLD) application including:
    1. A proposal statement which specifies you are applying to permit your unpermitted ADU or JADU under Government Code Section 66311.7 (AB 2533).
    2. Documentation demonstrating the ADU or JADU was created prior to January 1, 2020. See 4-0-13 Submittal Checklist for Unpermitted ADUs and JADUs for possible submittal items.
    3. Plans and documents that adequately demonstrate the building is not substandard as described by 4-0-13 Submittal Checklist for Unpermitted  ADUs and JADUs. Refer to BPC-021 Residential Building Permit for Projects that Require Plans and BPC-002 Residential Plan Checklist for typical plans and documents included in building permit submittals.
  2. Pay initial fees for application review.
    1. Once initial fees are paid, application review can begin. See Fees for ADUs and JADUs for more information.
    2. Staff will review submitted documentation to verify:
      1. Adequate proof has been provided for the time of construction.
      2. Consistency with Section 17920.3 of the Health and Safety Code.
  3. Schedule a site inspection with Permit Sonoma staff to confirm the unit's existing condition is not substandard as defined by Section 17920.3.
    1. Noncompliance with health and safety standards found during the inspection will not result in penalization.
    2. The inspector may provide recommendations to comply with health and safety standards necessary to obtain a permit.
  4. Correct substandard conditions, if needed.
    1. If necessary, make recommended corrections to obtain a permit and schedule a new inspection.
    2. Additional permits may be required to correct any present substandard conditions.
  5. Pay final fees for inspection and permit issuance.
      1. Impact fees or connection or capacity charges will not be required except when utility infrastructure is required to comply with Health and Safety Code Section 17920.3 and when the fee is authorized by Government Code Section 66311.5(e). See Fees for ADUs and JADUs for more information.
  6. Receive your permit.