ADU Pass
Thousand Oaks
Ventura County portion
Also in: No County
ADU Pass helps homeowners in Thousand Oaks, Ventura County, California navigate the permit paperwork for building an accessory dwelling unit. This area covers 3 ZIP codes.
Map
ADU details
ADU legality: allowed
California preempts most local ADU restrictions. Thousand Oaks permits ADUs by right in single-family zones per its zoning ordinance.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $1,700 | $73,500 | $75,200 |
| 600 | 600 | $1,700 | $294,000 | $295,700 |
| midpoint | 675 | $1,700 | $330,750 | $332,450 |
| maximum | 1,200 | $1,700 | $588,000 | $589,700 |
Fee breakdown
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU explicitly permitted; California owner-occupancy preemption (where applicable) makes ADU eligible for full landlord-tenant treatment.
- Short-term rental: with-restrictions STR rules vary by city. Thousand Oaks regulates STRs separately from ADU permitting; check local STR ordinance and HOA covenants.
- Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
- Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
- Studio / workshop: yes Personal artist studio is a permitted accessory use.
- Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
- Relative support: yes Family-occupancy ADU explicitly permitted in single-family zones.
Utilities
- Water: Thousand Oaks Water Utility · 21d connect · $4,500
- Sewer: Thousand Oaks Sewer / Wastewater · 21d connect · $5,500
- Electric: Thousand Oaks Electric Utility · 14d connect · $1,800
- Gas: Thousand Oaks Gas Utility · 21d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 8mo · typical 12mo · worst 18mo
Financing
Insurance impact
HOA prevalence & preemption
California has the strongest statewide HOA-preemption regime in the US for accessory dwelling units, built from two bills: AB 670 (2019) voided ADU-prohibiting covenants on single-family residential lots, and AB 3182 (2020) extended and codified the preemption into the Davis-Stirling Common Interest Development Act (Civil Code §§ 4740 / 4741). The combination prohibits common-interest communities from banning ADUs, restricting rentals below 25% of separate interests, or treating ADUs as separate HOA interests. Limits remain: HOAs retain authority over reasonable design standards and statutory height limits, and the 2026 Carlsbad case (CalMatters coverage) established that an HOA's documented design-standards regime can effectively delay or constrain ADU approval short of outright prohibition.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Legal history (timeline)
Current ordinance: City of Thousand Oaks Municipal Code — Accessory Dwelling Units, adopted 2020-01-01, last amended 2024-04-01
- 2020-01-01 — Accessory Dwelling Units — foundational statewide preemption (state-law)
California accessory-dwelling unit legislation.
Effect: Established the by-right ADU framework: required cities to permit at least one ADU + one JADU per single-family lot, 60-day ministerial approval, statewide minimum size allowances, and prohibition on most owner-occupancy requirements. Foundation that every subsequent bill builds on. - 2020-01-01 — Accessory dwelling units — fee caps (state-law)
California accessory-dwelling unit legislation.
Effect: Prohibits any impact fee, connection fee, or capacity charge on ADUs under 750 sqft. For ADUs 750 sqft and larger, impact fees must be proportional to ADU size relative to the primary dwelling (prohibits flat fees that hit a 900 sqft ADU the same as a 3,000 sqft house). Pre-SB-13 impact fees in LA historically ran $8,000-$15,000 per ADU. - 2020-01-01 — Accessory dwelling units — HOA covenant void (state-law)
California accessory-dwelling unit legislation.
Effect: Voids any deed restriction, covenant, or similar instrument that prohibits or unreasonably restricts ADU construction on single-family residential lots. Creates the legal baseline for AB 3182's broader HOA preemption. - 2020-01-01 — Housing — rental restrictions and ADU preemption in common-interest developments (state-law)
California accessory-dwelling unit legislation.
Effect: Amended Civil Code §§ 4740 / 4741 (Davis-Stirling Common Interest Development Act). Prohibits HOAs from (a) banning ADUs or JADUs; (b) restricting rentals below 25% of separate interests; (c) treating ADUs/JADUs as separate interests; (d) counting owner occupancy of a separate ADU as 'tenant' occupancy of the primary dwelling. - 2020-01-01 — Accessory dwelling units — height standardization and size caps (state-law)
California accessory-dwelling unit legislation.
Effect: Standardized detached-ADU height allowances (up to 16 feet single-story, higher in some transit/multi-story cases). Increased max ADU size to 850 sqft for studios and 1-BR, 1,000 sqft for 2+BR. Clarified JADUs under 500 sqft don't need separate utility connections. Confirmed prefab / factory-built tiny homes qualify as ADUs when placed on permanent foundations. Both effective 2023-01-01. - 2020-01-01 — Accessory dwelling units — permanent elimination of owner-occupancy requirement (state-law)
California accessory-dwelling unit legislation.
Effect: Permanently prohibits local governments from requiring owner-occupancy for ADUs or the primary dwelling as a condition of permitting an ADU. Effective 2024-01-01. Converts ADU investment from a primary-residence-plus-rental hybrid into a conventional rental-property business model across the entire state. - 2024-01-01 — City of Thousand Oaks ADU code refresh (city-ordinance)
Conforming local-code amendments aligning with current California accessory-dwelling framework.
Effect: Codified by-right ADU standards consistent with state law and local zoning.
Ventura County — county ADU rules and overlays
County ADU ordinance
California state — ADU law and programs
State ADU law
California has the most aggressive statewide ADU preemption regime in the US, built from ~15 bills passed 2019-2025 and enforced by the Department of Housing and Community Development (HCD). The 2026 HCD ADU Handbook addendum (in effect with the 2025 Title 24 code cycle) is the operative state-level reference. The regime does four things at once: (1) preempts local zoning that would ban or unreasonably restrict ADUs; (2) imposes by-right ministerial approval with short statutory deadlines; (3) caps fees and utility-connection charges; and (4) empowers HCD to void non-compliant local ordinances.
State HOA preemption
California has the strongest statewide HOA-preemption regime in the US for accessory dwelling units, built from two bills: AB 670 (2019) voided ADU-prohibiting covenants on single-family residential lots, and AB 3182 (2020) extended and codified the preemption into the Davis-Stirling Common Interest Development Act (Civil Code §§ 4740 / 4741). The combination prohibits common-interest communities from banning ADUs, restricting rentals below 25% of separate interests, or treating ADUs as separate HOA interests. Limits remain: HOAs retain authority over reasonable design standards and statutory height limits, and the 2026 Carlsbad case (CalMatters coverage) established that an HOA's documented design-standards regime can effectively delay or constrain ADU approval short of outright prohibition.
State financing programs
California's flagship state-level ADU financing program — the CalHFA ADU Grant Program — is paused and has not been refunded since the original $100 million allocation was fully deployed 2023-12-28. The program provided up to $40,000 per qualifying homeowner for pre-construction and non-recurring closing costs and financed approximately 2,500 ADUs in two rounds. As of 2026-04, no new funding round has been announced in the state budget. CalHFA continues to publish anti-scam warnings because bad actors actively solicit homeowners claiming access to grant funds that no longer exist. State-level financing activity has shifted to local pilot programs (San Francisco, San Jose, Los Angeles, San Diego) and private financing products (Fannie Mae ADU mortgage, HELOC, construction-to-permanent).
State housing programs
California's state-level ADU programs are concentrated at HCD (technical guidance, ordinance review, enforcement) and the paused CalHFA grant pipeline (covered under stateFinancing). The state does not operate a central pre-approved ADU plan library — instead, AB 1332 (2024) created a preemption framework for local pre-approved plans with a 30-day ministerial-approval deadline, and major cities (Los Angeles, San Diego, San Jose, Sacramento, Berkeley) have rolled out their own plan catalogs. The California YIMBY coalition and other housing-policy organizations play an influential role in bill drafting; they are not state agencies but effectively drive much of the ADU legislative agenda. The Title 24 code cycle (now 2025, in effect for 2026 permits) is the authoritative building-code baseline.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Codes
- 91360
- 91361
- 91362
Post Office
- 3435 E Thousand Oaks Blvd, 91362