ADU Permits and Approvals in Thousand Oaks

Who Issues ADU Permits in Thousand Oaks

Parcels within city limits are handled by Thousand Oaks Community Development. Its planners check the ADU application against zoning and the ADU ordinance, and its Building Division runs plan check and issues the building permit. The city asks applicants to review its ADU Application Completeness Review handout before submitting, and we build every city package against it.

Several neighborhoods with a Thousand Oaks or Newbury Park address are not city land. The county still governs Kelly Estates, Casa Conejo, Lynn Ranch, Ventu Park and Rolling Oaks as islands inside the city, and Santa Rosa Valley is unincorporated county land to the north. ADUs there are reviewed by the Ventura County Resource Management Agency, first by its Planning Division and then by Building and Safety. Submitting to the wrong agency costs weeks, so we confirm jurisdiction from the parcel record at the start.

Thousand Oaks ADU Ordinance 1747-NS and State Law

The city adopted Ordinance No. 1747-NS on March 10, 2026, updating its local ADU rules. On June 1, 2026, the state Department of Housing and Community Development sent the city a letter finding parts of the ordinance out of compliance with state ADU law and gave it until July 1 to respond. The city may amend the ordinance or explain its reading, and local standards can shift as that plays out.

For an owner, the takeaway is that state law sets the floor. Where a local provision conflicts with the statute, the statute governs. We check each local standard we rely on against current state ADU law, now numbered as Government Code sections 66310 through 66342, and against the latest city guidance before the plans go in.

On the county side, Ventura County updated its ADU and JADU rules in its Non-Coastal Zoning Ordinance in 2024, and HCD confirmed in January 2025 that the update complies with state law.

ADU Permit Timelines Under State Law

State law gives applicants firm review clocks, and they apply to the city and the county alike. As of 2026, an agency gets 15 business days to tell you, in writing, whether the file is complete and what is missing if it is not. After that, on a lot that already holds a house, the clock for a yes-or-no decision is 60 days. If the answer is no, the letter must spell out each deficiency and how to cure it.

Those clocks cover the agency's review time, not the whole process. Correction rounds, engineering revisions, an oak tree permit and separate sign-offs from fire, public works or the water purveyor all add calendar time. The fastest permits come from complete, well-coordinated plans and quick responses to comments, and that is where we spend our effort.

Review must also be ministerial. No public hearing, no neighbor notice and no discretionary design review applies to an ADU that meets objective standards.

• 15 business days for a completeness decision in writing
• A decision on a complete file within 60 days
• Each deficiency spelled out if the answer is no
• Appeal process with a written decision within 60 business days

Oak Tree Permits, Fire Review and Other ADU Sign-Offs

Many Thousand Oaks ADU projects need more than the ADU permit. The city regulates the care, pruning and removal of certain oaks and landmark trees, and an oak tree permit goes through Community Development. If a footprint, foundation or trench enters a protected zone, we prepare the arborist report and protection plan and run that permit alongside the ADU review.

Ventura County Fire reviews access, hydrant distance and sprinkler questions where they apply, and lots in a mapped fire hazard zone need wildland-urban interface construction details on the plans. Utility clearances come from the water purveyor serving the lot, the sewer provider and SCE. We collect those sign-offs in parallel so none of them holds up permit issuance.