Santa Monica's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Santa Monica, California, there are 5 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Shed Rules

Santa Monica regulates accessory buildings under SMMC §9.21.020. Sheds and similar structures in residential zones must comply with setback and height requirements. Sheds may not contain a kitchen unless approved as an ADU.

Key details: Code Section: SMMC §9.21.020. Kitchen Restriction: Not allowed (ADU exception). Permit Exempt: Walls under 4ft, fences under 7ft. Dwelling Use: ADU approval required. ADU Standards: SMMC §9.31.025 (separate).

Unpermitted accessory buildings or structures used as dwellings without ADU approval are code violations subject to enforcement action and fines.

ADU Rules

Santa Monica regulates ADUs under SMMC §9.31.025. Maximum size is 650 sq ft on lots up to 6,000 sq ft or 800 sq ft on larger lots. No development fees. Ministerial approval process.

Key details: Code Section: SMMC §9.31.025. Max Size (small lot): 650 sq ft (lots ≤6,000 sf). Max Size (large lot): 800 sq ft (lots >6,000 sf). Setbacks: 4 feet rear/side (new). Dev Fees: None.

Unpermitted ADUs may face code enforcement action, fines, and orders to remove or bring into compliance. Rental violations may result in additional penalties.

Garage Conversions

Santa Monica allows garage conversions to ADUs under SMMC §9.31.025. Replaced parking spaces do not need to be provided. Conversions of existing structures are exempt from setback requirements.

Key details: Code Section: SMMC §9.31.025. Replacement Parking: Not required. Setback Exemption: Existing structures exempt. JADU in Garage: Allowed (attached garage). Transit Parking Exempt: Within 1/2 mile of transit.

Unpermitted garage conversions are code violations. The conversion must receive ministerial approval and comply with building code requirements for habitable space.

Carport Rules

Carports in Santa Monica are regulated as accessory structures under the zoning ordinance. Building permits are required. In R1 districts, accessory buildings have specific setback and height requirements distinct from the primary dwelling.

Key details: Permit: Building permit required. R1 Setbacks: 5 ft rear, side per district. Height: Per accessory structure limits. Code: SMMC Article 9, Division 2.

Unpermitted carports: stop-work orders, required removal or retroactive permitting with penalty fees. Fines $200 to $1,000.

Tiny Homes

Tiny homes on foundations in Santa Monica are regulated as ADUs under CA Gov Code §65852.2 and the local zoning code. Tiny homes on wheels are not permitted as permanent dwellings. The city must allow ADUs per state law.

Key details: On Foundation: Regulated as ADU. On Wheels: Not permanent dwelling. State Law: CA Gov Code §65852.2. Permit: Building permit required.

Unpermitted dwellings: removal or retroactive permitting. Zoning violations: fines and required relocation. Occupancy without certificate: prohibited.

The Bottom Line

Santa Monica's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Santa Monica is broadly strict or permissive.

These rules come from Santa Monica's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.