Santa Monica, CA Accessory Structures: ADU Rules (2026)
ADU rules in Santa Monica, CA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Max size (studio/1BR ADU)
- 850 sq ft
- Max size (2+ BR ADU)
- 1,200 sq ft
- Max size JADU
- 500 sq ft
- Side/rear setback (detached ADU)
- 4 feet
- Max height (detached ADU)
- 2 stories or 24 feet
- City approval deadline
- 60 days (deemed approved if missed)
Summary
Santa Monica allows ADUs and JADUs by-right on residential parcels, approved ministerially within 60 days, with detached ADUs limited to 850 sq ft (studio/1BR) or 1,200 sq ft (2+ BR), 4-foot side/rear setbacks, and a maximum height of 2 stories or 24 feet.
D. ADUs and JADUs Permitted By-Right. An ADU or JADU that conforms to all standards of this Section shall be permitted by-right, and shall be considered and approved ministerially without discretionary review or a hearing. ... c. Detached ADUs. One detached, new construction, ADU is permitted per parcel with a proposed or existing single-unit dwelling if all of the following apply: i. Setbacks. (1) Front Setback. The front setback of the underlying zoning district shall apply. (2) Side and Rear Setbacks. 4 feet. ii. Minimum Size. The minimum size of an ADU is 150 square feet of floor area. iii. Maximum Size. (1) The maximum size of studio or one-bedroom ADU is 850 square feet of floor area. (2) The maximum size of an ADU with more than one bedroom is 1,200 square feet of floor area. iv. Height. 2 stories or 24 feet. ... L. Parking. 1. Required Parking. No parking shall be required for an ADU or JADU.
Full Breakdown
An ADU or JADU conforming to Section 9.31.025 is permitted by-right without discretionary review or a hearing. The City must act within 60 days; an unanswered completed application is deemed approved. Detached ADUs on single-unit parcels require 4-foot side and rear setbacks and may not exceed 2 stories or 24 feet. Converted ADUs within existing structures require no setback for the existing footprint. Studio/1-bedroom ADUs cap at 850 sq ft; those with 2+ bedrooms at 1,200 sq ft. JADUs are limited to 500 sq ft and must be contained within the walls of the single-unit dwelling. No parking is required for any ADU or JADU. Up to 8 detached ADUs may be added to a parcel with an existing multi-unit dwelling.
Violations & Fines
Violations of zoning or building standards are subject to enforcement and abatement under SMMC Chapter 9.48. The City may not deny an application based on correction of nonconforming zoning conditions that do not affect construction of the ADU.
Frequently Asked Questions
Do I need to provide parking for my ADU?
Can I build a detached ADU in my backyard?
How long does approval take?
Sources & Official References
Other rules in Santa Monica
How Santa Monica compares: Easiest Cities to Build an ADU·California rules heatmap·Compare Santa Monica to another location·View the California accessory structures overview
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ADU Rules in Nearby Cities
How other cities in Los Angeles County handle adu rules.