How Thousand Oaks Handles Accessory Structures: A Practical Guide

Thousand Oaks maintains 193 local ordinances across all categories, and 9 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Thousand Oaks falls on the strict-to-permissive spectrum compared to other cities.

Tiny Homes

Tiny homes on permanent foundations are regulated as ADUs under California state law and TOMC Chapter 9. Tiny homes on wheels are classified as recreational vehicles and cannot be used as permanent dwellings in residential zones. Minimum dwelling size requirements apply.

Key details: On Foundation: Regulated as ADU, permitted. On Wheels: Classified as RV, no permanent dwelling. Min Size (JADU): 150 sq ft. State Law: CA Gov Code 65852.2.

Using a tiny home on wheels as a permanent dwelling is a zoning violation subject to code enforcement. Building a tiny home without proper permits results in stop-work orders and retroactive permitting.

Carport Rules

Carports in Thousand Oaks require a building permit and must comply with TOMC Chapter 9 setback and lot coverage requirements. Carports in front yards may be restricted depending on the zoning district. Materials and design must be compatible with the primary structure.

Key details: Permit: Building permit required. Setbacks: Typically 5 ft side and rear. Lot Coverage: Counts toward maximum. HOAs: May have additional restrictions.

Building a carport without a permit results in stop-work orders and retroactive permitting requirements with penalty fees. Non-compliant structures may be required to be modified or removed.

ADU Permits

Thousand Oaks issues Accessory Dwelling Unit (ADU) permits ministerially under Title 9 of the Thousand Oaks Municipal Code (TOMC), which implements California Government Code §65852.2. ADUs and Junior ADUs (JADUs) are allowed in any residential zone where a single-family or multifamily dwelling is permitted. The 60-day statutory review applies — no public hearing, no discretionary design review.

Key details: Code Reference: TOMC Title 9; Gov. Code §65852.2. Review Type: Ministerial (no hearing). Statutory Deadline: 60 days. Detached ADU Max: 1,200 sq ft. JADU Max: 500 sq ft.

Building an ADU without permits violates TOMC Title 9 (zoning) and Title 8 (building code adoption), enforceable via stop-work order, mandatory after-the-fact permitting at investigation rates, administrative citations under TOMC Chapter 1 enforcement, and recordation of a notice of violation. Unpermitted ADUs cannot legally be rented and must be disclosed at the point of sale under California Civil Code §1102.

Thousand Oaks is more permissive than most cities when it comes to adu permits. That said, there are still limits.

ADU Rental Restrictions

Thousand Oaks ADUs may be rented as long-term housing (terms longer than 30 days). Short-term rental of an ADU is restricted by Gov. Code §65852.2(a)(6) and TOMC Title 9 — ADU rentals must exceed 30 days. JADUs carry an additional recorded deed restriction explicitly barring short-term rental.

Key details: Min Rental Term: More than 30 days. Short-Term Rental: Prohibited. JADU Deed Restriction: Required (no STR). AB 1482: Applies to long-term ADU tenancies. Statute: Gov. Code §65852.2(a)(6).

Renting an ADU for less than 31 days violates TOMC Title 9 and (for JADUs) the recorded deed restriction. Enforcement is via administrative citations under TOMC Chapter 1, with continuing daily violations. Hosts also expose themselves to back-tax assessment for unpaid Transient Occupancy Tax (TOMC Title 3) and potential civil penalties.

ADU Impact Fees

California Government Code §65852.2(f) prohibits Thousand Oaks from charging any impact fees on ADUs smaller than 750 square feet. ADUs of 750 sq ft or larger may be charged impact fees only in proportion to the primary dwelling's size. Utility connection fees for ADUs within an existing home are similarly capped by state law.

Key details: Under 750 sq ft: No impact fees allowed. 750+ sq ft: Proportional to primary unit. Statute: Gov. Code §65852.2(f). School District: Conejo Valley USD (fees on ADUs 500+ sq ft). Estimate Office: Community Development, 805-449-2100.

Charging impact fees in excess of the state-law caps is itself unlawful. Applicants overcharged in violation of Gov. Code §65852.2(f) can petition the City for refund, and, after exhausting administrative remedies, seek a writ of mandate under Code of Civil Procedure §1085. There is no penalty to the owner for compliant ADU construction.

Thousand Oaks is more permissive than most cities when it comes to adu impact fees. That said, there are still limits.

ADU Owner Occupancy

Thousand Oaks cannot require the property owner to live on-site to operate a standard ADU, per AB 881 / AB 976 and Gov. Code §65852.2(a)(7). Junior ADUs (JADUs) under TOMC Title 9 still require owner-occupancy of either the JADU or the primary dwelling, memorialized in a deed restriction recorded with Ventura County.

Key details: ADU Owner Occupancy: Not required (Gov. Code §65852.2(a)(7)). JADU Owner Occupancy: Required (Gov. Code §65852.22). Deed Restriction: JADUs only; recorded with Ventura County. Statutes: AB 881 / AB 976 / AB 1033.

Imposing an owner-occupancy condition on a standard ADU in violation of Gov. Code §65852.2(a)(7) is unlawful; the City would have to strike the condition. For JADUs, breach of the recorded deed restriction (e.g., neither owner nor tenant living on-site) is enforceable through the deed restriction's remedies, plus TOMC zoning enforcement (administrative citations, abatement) and potential conversion-back orders.

If you are coming from a city with tighter rules, you will find Thousand Oaks gives residents more flexibility on adu owner occupancy.

ADU Rules

Thousand Oaks Ordinance 1732-NS (Nov. 22, 2024) governs ADUs. Detached ADUs up to 1,200 sq ft; 4-foot side/rear setbacks; up to 16 ft height for detached. Attached ADUs up to 50% of primary or 1,200 sq ft, up to 25 ft height. JADUs max 500 sq ft. Minimum 30-day rental per state law.

Key details: Detached ADU: Up to 1,200 sq ft / 16 ft height. Setbacks: 4 ft side/rear. JADU: Max 500 sq ft. Min Rental: 30 days (CA Gov Code §65852.2). Ordinance: Ord. 1732-NS (Nov. 22, 2024).

Building an ADU without permits: stop-work order, double retroactive permit fees, and fines of $250-$1,000/day. Occupying an unpermitted ADU: zoning violation with requirement to vacate. Non-compliant ADUs may face demolition orders if not brought into compliance. However, state law requires cities to approve compliant ADU applications ministerially within 60 days.

Garage Conversions

Garage conversions to ADUs are allowed under CA state law and TOMC Ord. 1732-NS. Existing setbacks are exempt for conversions. Replacement parking is not required when a garage is converted to an ADU. Interior garage parking spaces must remain for non-ADU structures.

Key details: Conversion Allowed: Yes (ADU use). Setback Exemption: Existing setbacks apply. Replacement Parking: Not required. Non-ADU Garages: Must maintain interior parking spaces.

Converting a garage without permits: building code violation with stop-work orders and double retroactive fees. Occupying an unpermitted conversion: zoning violation with fines of $100-$500/day and requirement to restore or obtain permits. Non-owner-occupied JADU: violation of JADU requirements. State law protects compliant conversions from city denial.

Shed Rules

Accessory structures (sheds, garages) in Thousand Oaks are regulated under TOMC Title 9 zoning and building code. Permits required for structures over 120 sq ft. Must meet setback requirements. Cannot exceed primary structure height in residential zones.

Key details: Permit Threshold: Over 120 sq ft. Setbacks: Per TOMC Title 9 zoning. Height: Cannot exceed primary structure in R-zones. Topic: Shed Rules.

Shed over 120 sq ft without a permit: building code violation with double retroactive fees. Shed in setback area: code enforcement notice with 30 days to relocate or remove. Fines of $100-$500/day for non-compliance. Sheds used as living space: serious zoning violation with immediate enforcement.

The Bottom Line

Compared to many U.S. cities, Thousand Oaks gives residents more room on accessory structures. 3 of the 9 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

All of the above reflects Thousand Oaks's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.