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Accessory Dwelling Units (ADUs) and Junior ADUs
Accessory Dwelling Units and Junior Accessory Dwelling Units
Accessory Dwelling Unit (ADU): An ADU is a secondary residential unit on a single-family or multi-family property, typically ranging from 500 to 1,200 square feet. It offers complete independent living facilities, including a kitchen and bathroom. ADUs can be attached to the main house or detached.
Junior Accessory Dwelling Unit (JADU): A JADU is a smaller, more compact ADU, under 500 square feet, located within the existing building footprint such as converted garage or basement. It must have a separate entrance from the main house and provides essential living spaces such as a bedroom and a kitchenette. It may have its own bathroom or share with the primary residence.
Explore the possibilities of an ADU with the San Mateo County ADU Resource Center. Visit https://smcadu.org/ for information and resources to help you build your ADU.
HIP Housing is a nonprofit organization providing affordable housing solutions in San Mateo County.
Have a spare room or an ADU available for rent?
Contact HIP Housing at (650) 348-6660 or visit HIP Housing to learn how you can help.
The following documents, provided by the City of San Bruno and the State of California, will assist you in the design process of your ADU:
- Information for Submittal: City of San Bruno ADU Submittal Checklist (PDF)
- Design Standards and Requirement: City of San Bruno ADU Ordinance (PDF)
- HCD ADU Handbook: HCD ADU Handbook (PDF)
- Residential Design Guidelines: Residential Design Guidelines
Additional Requirements to Note:
Boundary surveys are required for new homes, additions, and Accessory Dwelling Units within 3 inches of the required setback.
All newly constructed, remodeled, or relocated buildings must have an approved water supply capable of meeting the required fire flow for fire protection, as determined by an approved method or Appendix B, Table B105.1(1) of the Fire Code.
Each residential unit, including any new Accessory Dwelling Unit (ADU), must be individually metered for gas and electric service in compliance with California Public Utilities Code Section 780.5, unless exempt (e.g., dormitories or certain employee housing). Separate metering is required to ensure utility billing and usage are tracked independently.
The following steps will assist you in applying for a building permit with the City of San Bruno Building Division. To proceed with the building permit process, please follow the steps below:
Apply on MGO Connect:
- Visit MGO Connect and click on "New Account" to get started.
- If you already have a MyGovernmentOnline account, use your existing login credentials.
- Within MGO Connect, apply for a Building Permit and upload the following documents:
- Plan sets
- ADU Submittal Checklist (recommended to expedite review)
MGO Connect Resources:
- You can find additional information about MGO Connect on the Online Permits page.
- MGO Connect also offers a mobile app available on the Apple App Store and Google Play Store. Search for "MGO Connect" to download.
The following outlines what to expect after submitting your building permit application.
- Once submitted, your plan sets are routed to reviewing departments: Building Division, Fire Department, Planning Division, and Public Works Department.
- The initial review usually takes 3-4 weeks.
- Reviewers may request corrections or additional information. Subsequent reviews typically take 1-2 weeks each.
- You will be notified of any required corrections and have one year to submit a revised plan set.
- Upon approval by all reviewers and securing a contractor, you can pull the permit and begin construction.
- Inspections will occur at key stages of construction.
If you have other questions about the building permit process, feel free to call the Building Division at 650-616-7074.
AB 1332: Pre-Approved ADU Program for Design Professionals
The City of San Bruno is pleased to announce the launch of our Pre-Approved Accessory Dwelling Unit (ADU) Program, designed to simplify and expedite the ADU permitting process in accordance with AB 1332. This program allows anyone to submit standardized ADU plans for pre-approval. Submitted plans will be reviewed for compliance with the Zoning Code and current Building Codes.
Submission Process:
- Applications must be submitted through the City of San Bruno's San Bruno's Online Permitting Portal.
- To obtain a pre-approved ADU plan review fee estimate, please contact the Building Division at Building@sanbruno.ca.gov or call (650) 616-7074.
- Each proposed unit must be applied as an individual permit.
- In the project description, please clearly indicate "Pre-Approved ADU Program."
- For submission purposes, please use the San Bruno City Hall address:
567 El Camino Real,
San Bruno, CA 94066.
Approved Plans:
- Approved ADU plans, along with the designer or architect's contact information, will be made available on this webpage. Applicants may designate whether complete or abridged plans (sample floor plan and elevation) are made available.
- Applicants may request the removal of their pre-approved plans from the website at any time. Plans will be removed within 30 days of such a request.
Please note: Posting of pre-approved plans does not constitute an endorsement by the City of San Bruno.
Permitting with Pre-Approved Plans:
- Future applicants shall contact the designer or architect to utilize these pre-approved plans when applying for an ADU permit through the City's Online Permitting Portal.