Can I Build ADU in Santa Monica, CA? (2026)
Find out if you can build a adu in Santa Monica, CA. Rules, permit requirements, costs, and next steps.
Yes, ADUs are allowed in Santa Monica, CA. California state law ensures by-right approval.
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a residential lot — also called a granny flat, in-law suite, or backyard cottage. In Santa Monica, CA, ADUs are permitted by right under state law, making them one of the most accessible ways to add housing on your property. ADUs can be detached, attached to the main home, or created by converting an existing garage or accessory structure.
ADU Rules in Santa Monica
ADU Rules in Santa Monica: Detached ADU max size: 1200 sq ft. Attached ADU max size: 50% of primary dwelling up to 1200 sqft. Junior ADU (JADU): up to 500 sq ft, within existing structure. Setbacks: 4 ft side, 4 ft rear. Owner-occupancy: Owner-occupancy requirement eliminated statewide January 1, 2020. Santa Monica cannot require owner-occupancy. However, note that Santa Monica's Rent Control Charter Amendment (RCCA) applies to many residential units — tenants in rent-controlled units have strong protections against owner move-ins.. State preemption applies: CA law requires Santa Monica to approve compliant ADUs by right.
Costs & Fees
ADU permits in Santa Monica: Total estimated permit cost: $3,000–$12,000 total permit fees — higher than most CA cities due to Santa Monica's premium fee schedule. Contact the Santa Monica Community Development Department — Building and Safety Division for current fee schedule.
Timeline
Santa Monica Community Development processes ADU permits through SMGovNet online portal. Ministerial approval within 60 days per state law. Plan review typically 4-8 weeks due to high permit volume in this dense city. Construction 4-12 months. Santa Monica's Coastal Zone status for beachside properties adds Coastal Development Permit requirements.
Next Steps
Next steps for building an ADU in Santa Monica: 1. Review full ADU rules including size limits, setbacks, and parking. 2. Apply for an ADU permit through the Santa Monica Community Development Department — Building and Safety Division at https://eservices.smgov.net/. 3. Hire a licensed contractor familiar with CA ADU requirements.
Santa Monica Community Development Department — Building and Safety Division
Phone: (310) 458-8355
Website: https://www.santamonica.gov/departments/community-development/building
Online Permits: https://eservices.smgov.net/
Frequently Asked Questions
Can I do Airbnb in Santa Monica?
Santa Monica has some of California's strictest short-term rental restrictions. Whole-home rentals where you (the host) are not physically present are effectively banned — only 'home-sharing' where you remain on the premises is permitted. You must register ($200/year) and be a permanent resident of the property. Renting your entire home while you travel is prohibited. Airbnb actively enforces Santa Monica's ordinance and removes unregistered listings. Violations carry fines up to $1,500 per day for unhosted rentals.
Does Santa Monica rent control apply to an ADU I build?
Generally, new ADUs built in a standalone new structure or converted garage after 1995 are exempt from Santa Monica Rent Control under Costa-Hawkins Rental Housing Act. However, ADUs created within existing multifamily buildings built before 1979 may be subject to the Santa Monica Rent Control Charter Amendment. This is complex — consult the Santa Monica Rent Control Board (310-458-8751) or a local attorney before creating an ADU in or adjacent to a rent-controlled building.
Does my Santa Monica property need a Coastal Development Permit for an ADU?
Properties in Santa Monica's Coastal Zone (generally west of Lincoln Blvd, plus Palisades Park and some beachfront properties) require a Coastal Development Permit (CDP) from the City of Santa Monica's Coastal Manager in addition to a standard building permit. The CDP review for ADUs that comply with the Local Coastal Program is typically ministerial (2-4 weeks). Contact Santa Monica Planning at (310) 458-8341 to determine if your property is in the Coastal Zone before submitting your ADU application.
What are the height limits for homes in Santa Monica?
R1 single-family zones (North of Montana, Sunset Park, North Santa Monica) limit buildings to 28 feet and 2 stories. Neighbors in R1 neighborhoods closely monitor height and setback compliance. Multifamily zones (R2, R3, R4) allow 30-50 feet. The Mixed Use (MU) zone along the Metro E Line corridor allows up to 65 feet for mixed-use buildings. All structures must comply with California Fire Code ladder access requirements above 50 feet.
How do I sell cottage food products in Santa Monica?
Santa Monica's famous farmers markets (Wednesday and Saturday on Arizona Avenue) are prime venues for cottage food sellers. Register your home kitchen as a Class A Cottage Food Operation with LA County Environmental Health (no revenue cap for direct sales). No city permit beyond the standard Business License is required. The Santa Monica farmers markets are among California's highest-volume direct-to-consumer food markets — cottage food vendors often do $1,000-2,000 per market day at peak season.
What is the difference between Santa Monica's R1, R2, and R3 zones?
R1 (Single-Family) is found primarily in North of Montana (north of Montana Ave) and Sunset Park (south of Olympic Blvd). It allows only one primary dwelling per lot plus an ADU and JADU per state law. R2 (Two-Family) allows duplexes and small apartment buildings — common in Ocean Park and Mid-City. R3 (Medium Multifamily) and R4 (High Multifamily) are concentrated near downtown, Wilshire Blvd, and the Metro E Line corridor, allowing 3-4+ story apartment buildings. Use Santa Monica's zoning map at smgov.net to find your parcel's zone.
Can I have both an ADU and a JADU on my Santa Monica R1 lot?
Yes. California state law (Gov Code 65852.2 and 65852.22) allows one standard ADU (up to 1,200 sqft detached or attached) AND one Junior ADU (up to 500 sqft within the existing structure) simultaneously on a single-family R1 lot. In Santa Monica's market, both can command premium rents — a 1,200 sqft detached ADU can rent for $4,000-6,000/month, while a 500 sqft JADU within the main house can rent for $2,500-3,500/month. Note rent control and Coastal Development Permit implications before proceeding.
Source: Santa Monica Community Development Department — Building and Safety Division — Building Regulations. Last verified April 6, 2026. View source