Palo Alto / Accessory dwelling units
ADU Builder in Palo Alto
Palo Alto publishes an ADU/JADU handbook and Municipal Code Chapter 18.09. A smaller detached unit and a larger unit are not the same local path. R&B Master Construction Inc. (CSLB #1158657) takes Palo Alto questions at the Cupertino office, 10080 N Wolfe Road, Suite SW3-200. Call (650) 562-6324.
The handbook path, and units past that path
Palo Alto’s ADU/JADU materials describe an exempt-style detached path for units up to about 800 square feet, with 4-foot side and rear setbacks and height limits around 16 feet. Larger attached or detached units, including size themes up to roughly 900 square feet or about 1,000 square feet with two or more bedrooms, face more local standards. Those words follow the City materials. The exact caps for a parcel are in the 2025 handbook and Chapter 18.09, and they should be read there before design lock-in.
A junior accessory dwelling unit, under the handbook themes and Chapter 18.09, is created within the primary dwelling, is limited to 500 square feet, and may share bathrooms while providing an efficiency kitchen and required access. It is not a detached backyard ADU. Owner-occupancy and deed-restriction details belong in the current handbook.
Accela, and the master ADU checklist
Palo Alto directs building-permit applications through Accela Citizen Access. Detached ADUs use the City’s master ADU checklist, which covers architectural, structural, MEP, CALGreen, and Title 24 energy documents. Start at the City’s Apply for a Building Permit page. City staff decide code compliance. When permitting is in the contract, we coordinate the package and the City comments from the Cupertino office.
ADU Builder in Palo Alto — FAQ
What is a streamlined detached ADU path in Palo Alto?
Palo Alto’s ADU/JADU materials describe an exempt-style detached ADU path for units up to about 800 square feet with 4-foot side and rear setbacks and height limits around 16 feet, separate from larger units that face more local standards. Always confirm the current Palo Alto ADU/JADU Handbook (2025) and Municipal Code Chapter 18.09 for your lot before design. R&B (CSLB #1158657) can review fit — info@rbmasterconstruction.com.
How do I apply for a Palo Alto ADU building permit?
Palo Alto directs building-permit applications through Accela Citizen Access (ACA), with detached ADUs using the City’s master ADU checklist covering architectural, structural, MEP, CALGreen, and Title 24 energy documents. Start at the City’s Apply for a Building Permit page. When permitting is in contract, R&B Master Construction Inc. coordinates the package and City comments — call (650) 562-6324.
What is a JADU under Palo Alto rules?
Under Palo Alto Chapter 18.09 themes and the City handbook, a junior accessory dwelling unit is created within the primary dwelling, is limited to 500 square feet, and may share bathrooms while providing an efficiency kitchen and required access. It is not the same as a detached backyard ADU. Confirm owner-occupancy and deed-restriction details in the current handbook before choosing JADU versus ADU.
Can Palo Alto ADUs be larger than 800 square feet?
Yes — City materials describe larger attached or detached ADUs, including size themes up to roughly 900 square feet or about 1,000 square feet with two or more bedrooms, subject to local standards beyond the streamlined ≤800-square-foot detached path. Lot conditions, setbacks, and height still control. Verify Chapter 18.09 and the 2025 handbook for the exact caps that apply to your parcel.
Who should I contact at the City about Palo Alto ADU zoning?
Use Palo Alto Planning & Development Services resources linked from the ADU handbook and building-permit pages, and submit plans through Accela Citizen Access. For a contractor conversation about design, permits, and build scope, contact R&B Master Construction Inc. at info@rbmasterconstruction.com or (650) 562-6324 (CSLB #1158657). City staff—not the contractor—decide code compliance.
Official sources
City rules change. The links below are the pages and documents these notes were checked against. Your address can still differ.
Talk with R&B
R&B Master Construction Inc. · CSLB #1158657. Email info@rbmasterconstruction.com. Headquarters: 84 W Santa Clara St, Suite 700, San Jose, CA 95113. Hours: Monday–Sunday, Open 24 hours Pacific Time.