Fees associated with ADUs are comprised of several types: 

1. Planning Review Fee: Fee charged to review ADU plans for compliance with zoning standards, e.g. ADU size and location on a lot. This is a fixed fee based on the staff time and resources required. 
2. Building Fees: Plan check and permit fees cover the cost of reviewing plans, issuing permits, and performing inspections. These fees are variable, depending on building size and valuation. The average fees charged over the past three years are between $2,800 and $3,200 per unit.
3. Impact Fees and Utility Service/Connection Fees: These fees offset impacts to public services that result from the project, including impact fees from the City, Conejo Valley Unified School District, Thousand Oaks Police Department, Ventura County Fire Department, and Conejo Recreation and Park District. City fees include water and wastewater connection fees and traffic impact fees. These are a combination of fixed and variable fees.

Yes. Your taxes will increase based on the value of the ADU. Refer to the County Assessor’s website for more information.

ADUs and JADUs may be rented for a minimum term of 30 days, per state law. A detached or attached ADU, and the house, may be rented to different parties. However, any property with a JADU must be owner-occupied.

A homeowner renting their ADU/JADU must comply with fair housing laws. You cannot establish discriminatory terms or conditions in the rental advertising or agreement. You cannot advertise or establish that the unit is available or not available to people of a certain race, color, religion, sex, handicap, familial status, veteran/military status, national origin, or source of income including federal, state, or local public assistance and housing subsidies or vouchers. 

The City does not allow sale of ADUs separate from the rest of the property.

Here are several potential options:

1. Select a plan that has been preapproved by the City.
2. Units less than 750 sq. ft. will cost less to build, and in accordance with state law, these smaller units are not subject to impact fees such as parkland and school fees.
3. CalHFA provides funds towards pre-development and non-reoccurring closing costs associated with the construction of the ADU. Predevelopment costs include site prep, architectural designs, permits, soil tests, impact fees, property survey, and energy reports. Visit CalHFA's website or call (877) 922-5432 for information.

Architectural plans that are preapproved by the City enable the fastest permit process. You are still required to submit a site-specific plan that shows the location of the preapproved ADU.

HOMEOWNERS: The Thousand Oaks ADU Plans Gallery provides a variety of ADU designs from talented designers, including pre-approved plans that have been pre-reviewed for building code compliance. Browse and filter to find the perfect fit for your property, or simply to get inspired. Once you’ve chosen a design, connect directly with the architect or company to use or purchase before completing site planning for your property. 

Note: All plans – even pre-approved plans – still require customized site planning and permitting based on your property. This will include details like where the ADU sits on your lot, emergency access, and foundation plans.

DESIGNERS: Apply to have your ADU architectural and structural plans pre-approved using a standard building permit. When you apply, please use address 1 Standard Plans Way.

If you aren’t sure if your existing ADU or JADU was built with permits, you can check the property permit history by looking up the address on TO24.

Legalizing a living unit that has not had the benefit of a permit and inspections is in the property owner’s best interest, in the following ways:

1. More comprehensive and accurate homeowner insurance coverage in the event of property damage or loss
2. Reduced risks to occupants from potential unknown structural issues
3. Increased property values
4. Remove concern that a code violation citation for illegal construction and conversion to ADU or JADU could be issued.

If you do have an unpermitted ADU on your property, you can legalize it by applying for an ADU permit! Legalizing an unpermitted ADU or JADU requires the submittal of an ADU application. 

If your unpermitted ADU or JADU was constructed before January 1, 2020, the following applies, as provided in AB 2533-Accessory Dwelling Units:

The City shall not deny a permit for an ADU or JADU that is in violation of California building standards (codes) or does not comply with any local ordinance regulating ADUs or JADUs unless that building is deemed substandard pursuant to Section 17920.3 of the Health and Safety Code.

Before submitting an application for a permit, the homeowner may obtain a confidential third-party code inspection from a licensed contractor to determine the unit’s existing condition or potential scope of building improvements.

After receiving an application submittal, an inspector from the City may inspect the unit for compliance with health and safety standards and provide recommendations to comply with the health and safety standards necessary to obtain a permit. If the inspector finds noncompliance with health and safety standards, the City will not penalize the applicant for having the unpermitted accessory dwelling unit or junior accessory dwelling unit and will approve necessary permits, to be submitted by the applicant, to correct noncompliance with health and safety standards.

A homeowner applying for a permit for a previously unpermitted accessory dwelling unit or junior accessory dwelling unit constructed before January 1, 2020, shall not be required to pay impact fees or connection or capacity charges except when utility infrastructure is required to comply with Section 17920.3 of the Health and Safety Code.