Accessory Dwelling Units
Are you interested in building an Accessory Dwelling Unit (ADU) or Junior Accessory Dwelling Unit (JADU)? Then you’re in the right spot!
Frequently Asked Questions
See the City's responses to frequently asked questions about ADUs and JADUs.
What is an Accessory Dwelling Unit?
An Accessory Dwelling Unit (ADU) is an attached or detached residential dwelling unit that provides complete independent living facilities and is located on a lot with a proposed or existing primary residence. ADUs must include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as a single-family or multifamily dwelling.
What is a Junior Accessory Dwelling Unit?
A Junior Accessory Dwelling Unit (JADU) is a unit that is no more than 500 square feet and is contained entirely within a single-family residence. A JADU may include separate sanitation facilities, or may share sanitation facilities with the existing single-family home.
What are the City's regulations for ADUs and JADUs?
For information about the City's regulations and guidelines for ADUs/JADUs:
How do I apply for an ADU or JADU?
To apply for an ADU or JADU, you must submit two applications - a Building Permit application, and a Deed Restriction application.
Building Permit Application
You can find the Building Permit Application on the City's Permitting Portal. Please submit this application to the Building Division. Building Division staff will review the plans within 60 days, once the application is deemed complete.
Deed Restriction Application
You can find the Deed Restriction Application below. Deed Restrictions are required for both ADUs and JADUs. Please check-in with Planning Division staff before notarizing and submitting the forms.
Can I submit ADU plans for pre-approval, per AB 1332?
The City of South San Francisco is now accepting the submission of ADU plans for pre-approval, per AB 1332.
- Anyone may submit ADU plans for pre-approval. The submitted drawings do not need to be site-specific.
- Apply online by clicking here and note “Pre-Approved ADU Program” in the project description.
- Plans will be reviewed for conformance with the current City-adopted building and zoning codes. Fees for review will be based on the hourly rate listed in the City’s latest Adopted Master Fee Schedule, with a minimum rate of one-hour.
- Pre-approved ADU plans will be posted on this webpage along with the contact information of the applicant. Posting of pre-approved plans shall not be considered an endorsement of the applicant, and pre-approved plans will be removed from this webpage within 30 days of an applicant’s request for removal.
- Pre-approval expires at the end of the building code cycle (December 31, 2025).
To apply for a site-specific ADU Building Permit using the Pre-Approved ADU program:
- Pre-approved plans can be selected from this website once available.
- All site-specific information relating to your project must be provided as part of the application materials. Building Permit plan submittal and permit requirements can be found HERE.
- Apply online HERE. Once an application utilizing pre-approved ADU plans is deemed complete, the City will approve or deny the application within 30 days.
- Contact Building@ssf.net for a Building Permit fee estimate.
ADU Resources
The City has free resources to help you design an ADU or JADU. Read on to learn more!
San Mateo County ADU Resource Center
Visit the San Mateo County ADU Resource Center for help from beginning to end in the process to build an ADU. The Resource Center has information about getting started, understanding the rules, budgeting, design, permitting, construction, and move-in & renting.
Support with Designing, Constructing, and Renting an ADU
The City of South San Francisco's "HelloADU" Program provides free help with designing, constructing, and renting an ADU or JADU. Visit www.helloadu.org to learn more.
How can HelloADU help me?
HelloADU is a service provided to residents of South San Francisco by Hello Housing, a nonprofit organization. Participating homeowners can receive:
- Free support - this program is no cost to you.
- Up to 100 hours of free support in designing, constructing, and renting out an ADU or JADU.
- Support from beginning to end, including:
- Studying the feasibility of locating an ADU or JADU on your property
- Helping you define your vision for your ADU or JADU
- Helping with designing the ADU or JADU, and estimating the costs
- Helping you to get the correct permits from the City
- Support during the construction phase
- If you would like to rent out your ADU or JADU, connecting you to landlord training and programs to find tenants
How can I apply for HelloADU's free help?
I'd like a quick summary of the program.
For a quick summary of the program, check out the following handouts:
Questions? Contact the HelloADU team.
If you have questions, please contact HelloADU team members by calling (415) 863-3036 or sending a message through their website: Contact HelloADU
Pre-Reviewed Designs for ADUs
Need help designing an ADU? San Mateo County HEART (Housing Endowment and Regional Trust) has prepared designs that have been pre-reviewed by the City of South San Francisco. These designs are for green, all-electric detached ADUs.
Download the Designs
How can this program help me with my ADU project?
These designs are free and pre-reviewed by the City of South San Francisco. This can help you can save you time and money on preparing plans and construction drawings.
You can choose from four different designs:
- Studio (400 square foot)
- One-bedroom unit (575 square feet)
- One-bedroom unit (745 square feet)
- Two-bedroom unit (800 square feet)
You can find the designs here.
You can pair these designs with support from the HelloADU program. As a companion to the HelloADU program, these pre-reviewed designs may reduce project management and permitting costs for any HelloADU program participants.
I'd like a quick summary of the program.
For a quick summary of the program, check out the following handouts: