Simi Valley, CA Accessory Structures: ADU Rules (2026)
ADU rules in Simi Valley, CA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Code section
- SVMC 9-44.160 (Ord. 1316, Nov. 2, 2020; amended 2023)
- Review
- Ministerial Zoning Clearance, 60-day deadline
- Setbacks
- Front 20 ft; side 4 ft; rear 4 ft
- Height
- 18 ft, single story
- Detached ADU max size
- 1,000 sq ft (parcels ≤8,000 sq ft); 1,200 sq ft (parcels >8,000 sq ft)
- JADU max size
- 500 sq ft, inside existing SFD
- Minimum size
- 220 sq ft
- Rental minimum
- 30 days
Summary
Simi Valley permits one ADU plus one JADU per single-family lot ministerially under SVMC 9-44.160, conforming the city to state law (Gov't Code 65852.2 and 65852.22) with 4-ft side/rear setbacks, 18-ft height, and up to 1,200 sq ft detached.
Notwithstanding any other regulation in this Development Code that is specifically applicable to ADUs or JADUs, a Zoning Clearance must be ministerially reviewed for an application for a building permit to create an ADU and/or a JADU within a residential zone subject to the development standards set forth in this section. The City reserves the right to limit construction of ADUs or JADUs in locations where there is inadequate water or sewer services, impact on traffic flow, or public safety. Neither ADUs nor JADUs shall count towards the allowable density for the lot upon which the ADU or JADU is located. The City shall act on the application to create an ADU or JADU within 60 days from the date an application is deemed complete if there is an existing single-family or multifamily dwelling on the lot. ... A minimum floor area of 220 square feet for an ADU or JADU is required per the California Building Code. The rental of any ADU or JADU, or the primary residence if the owner lives on site in the ADU or JADU, must be for periods of 30 days or more. Each ADU or JADU requires a separate entrance which shall not face the street unless the access to the unit required by the California Building Code is precluded by an existing permitted structure.
Full Breakdown
Per Ordinance No. 160 makes the creation of an ADU or JADU subject to ministerial Zoning Clearance review, no discretionary hearing, when the lot contains an existing or proposed single-family or multi-family dwelling in the OS, RE, RVL, RL, RM, RMod, RH, MH, RVH, or MU Overlay districts. Front setback is 20 ft; rear and side setbacks are 4 ft. ADUs are limited to a single story and 18 ft in height. A detached ADU may be up to 1,000 sq ft on parcels up to 8,000 sq ft and up to 1,200 sq ft on parcels over 8,000 sq ft, subject to lot-coverage limits in Table 4-4.
Attached ADUs are limited to 50% of the existing SFD or 800 sq ft (whichever is larger), up to 1,000 sq ft. The minimum size is 220 sq ft (California Building Code efficiency unit). A JADU is limited to 500 sq ft, must be located within the existing single-family dwelling, and requires a recorded owner-occupancy deed restriction. ADUs do not count toward allowable density, and the City must act within 60 days of a complete application. Rentals must be 30 days or longer, short-term ADU rentals are prohibited.
Violations & Fines
Building or occupying an ADU without a Zoning Clearance and building permit can trigger code enforcement, stop-work orders, and a requirement to remove or legalize the structure; a JADU rented out without the recorded owner-occupancy deed restriction must be vacated within 90 days of a new owner taking title.
Frequently Asked Questions
Do I need a public hearing to build an ADU in Simi Valley?
How big can a detached ADU be?
Can I short-term rent my ADU?
Sources & Official References
Other rules in Simi Valley
How Simi Valley compares: Easiest Cities to Build an ADU·California rules heatmap·Compare Simi Valley to another location·View the California accessory structures overview
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ADU Rules in Nearby Cities
How other cities in Ventura County handle adu rules.