Redwood City Accessory Dwelling Unit (ADU) Standards

        New laws were recently passed, and updates will be coming soon


You may contact the Planning Department and speak with any planner

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ADU Ordinance

Zones allowed

All residential zones (R1-5, RH)

Lot restrictions

Must be single-family dwelling

Minimum lot size None
Min / Max ADU size

Min: None

Max for lots under 10,000 sf: 700 sf

Max of ADA compliant ADU: 800 sf

Max for lots larger than10,000 sf: 900 sf

ADU building height

Attached: 28 feet

Detached:14 feet


Attached: Same as primary dwelling

Detached: 10 feet rear, 6 feet side

Parking requirements No parking required but, if provided, can be tandem and/or in driveway
Owner occupancy

Owner must live in the main dwelling or the ADU

Sample fees from recently built projects*

ADU 1 (487 sf, detached): $4,787

ADU 2 (638 sf, attached): $5,929

Other requirements
  • ADU may require fire sprinklers if the existing house already has fire sprinklers, or the total area of the ADU and any substantial remodeling equals 50 percent of the main living area or 1,000 square feet, whichever is less.
  • ADU must be generally consistent in shape, material and style to the primary dwelling.
  • If any structure on the lot is historic, additional standards may apply.
  • Conversions of existing structures (including garages) must comply with current building code (upgrades may be required).
  • Only one ADU per property is allowed.
  • ADUs must comply with all requirements of the underlying zoning district.

ADUs on the ground floor require a building permit, while second story ADUs require a planning entitlement in addition to the building permit. No deed restrictions are required. Making an appointment to meet with a planner in the initial stages of the project can help avoid challenges and is highly recommended.


People with disabilities may apply for a waiver of the rules.


Disclaimer: standards and process may vary. Consultation with the contact is recommended before starting any project.

*Detached ADUs are typically subject to building fees, impact fees and school fees. Attached ADUs are subject to the same fees plus an entitlement fee for second story units. Fees are specific to each project and will vary. Fees change regularly. These are provided as examples only.

Download ADU Standards PDF

Updated: 12/11/2017