Accessory and Junior Accessory Dwelling Units - ADUs and JADUs


Download a PDF brochure of this ADU information

An Accessory Dwelling Unit (ADU) is a small, independent living unit that is no more than 1,200 square feet in size.  It can be attached to or detached from a single-family dwelling (one dwelling per lot) or multifamily dwellings (two or more dwellings per lot).  ADUs can also be developed through the conversion of existing floor area. An ADU must have a kitchen, bathroom, and a separate entrance. ADUs can be built in any zoning district that allows residential uses.

A Junior Accessory Dwelling Unit (JADU) is a small, independent living unit that is no more than 500 square feet in size.   A JADU is contained entirely within a legally existing or proposed single-family dwelling, and must contain an efficiency kitchen and a separate entrance.  JADUs can be built in any zoning district that allows single-family dwellings.  The owner of the single-family dwelling must live on the property, in the single-family unit or the JADU.

There are many benefits in building an ADU or JADU:  

  • ADUs/JADUs can provide a more affordable housing opportunity for caregivers, grown children, elderly parents, or renters.  
  • ADUs/JADUs provide an income opportunity through renting the ADU or primary residence.  
  • “Empty nesters” can stay in their neighborhood by moving into a smaller ADU/JADU and renting their existing home to pay the mortgage and/or to provide additional income.

For more information, download the City of Healdsburg’s ADU/JADU Informational Brochure.  You’ll learn about:

  • Where you can build an ADU/JADU.
  • Development and design standards for ADUs including how many ADUs can be built, ADU size, height, and placement.
  • The permitting process.
  • How to take the first steps toward building an ADU/JADU.

For the City’s adopted ADU Ordinance, review Section 20.20.010 of the Healdsburg Land Use Code.

There are some City permits and fees required to develop an ADU:

Building Permit.  A building permit is required for all ADUs, including conversion of existing space or garage area. Building fees are based on the valuation of the ADU construction costs. Contact the City’s Community Development Department for more information at (707) 431-3346. 

Fire Sprinkler Permit. Additions and new construction requiring fire sprinklers will need separate plans to be submitted for fire sprinkler design to the Fire Department. Please contact the Fire Department at (707) 431-3360 for more information.

School Impact Fees. Additions or new construction over 500 square feet may be subject to school district fees. Please contact the Healdsburg Unified School District business office at (707) 431-3403 or visit the HUSD Website for more information.

Development Impact Fees. Impact fees are also required for a new ADU greater than 850 square feet in size. Impact fees for ADUs are based on the proportionate size of the ADU as compared to the “primary unit,” which will be either single-family or multifamily.  Impact fees for ADUs follow state guidelines and are at reduced rates from fees for other housing types.  For more information, see the Property Development Fees page.  You may also contact Planning and Building Department staff at (707) 431-3346 for assistance in determining applicable fees. 


The City of Healdsburg Community Development staff is here to assist you and make the path toward adding an ADU and/or JADU as easy as possible.  Staff is available to answer questions at the Community Development Center at City Hall or (707) 431-3346.

The City also offers the One-Stop Assistance Center.  If you are considering an ADU or JADU on your property, you can receive personalized information and guidance through the City’s One-Stop Assistance Center. One-Stop meetings are held on Thursday afternoons, at no cost, and staffed by members of the Planning, Building, Public Works, and Fire Departments to answer all your questions regarding ADU development. (To schedule an appointment for a One-Stop meeting, please call the Community Development Center at (707) 431-3346)

Napa Sonoma ADU Center.  The mission of the Napa Sonoma ADU Center is to help homeowners in Napa and Sonoma Counties build ADUs.  Its website contains a multitude of resources for property owners considering constructing an ADU.  The Center provides ADU feasibility consultations and helps identify costs through its ADU Calculator and provides pre-approved plans for construction. If you are considering a pre-approved plan via the Napa Sonoma ADU Website, please reach out to City staff.

The Napa Sonoma ADU Center has sponsored webinars specific to Healdsburg: