An ADU is a separate residential unit providing independent living facilities on a residentially zoned lot that already contains a legally established residential dwelling unit. The key distinction between an ADU and other types of detached structures, such as pool cabanas, is the inclusion of a kitchen in the ADU.

Procedurally, a key aspect of ADUs is that they are approved ministerially through issuance of building permits only. Discretionary permits for ADUs are prohibited under State law. Because ADUs are not discretionary actions, public notice is not provided as part of the application review process. 

Fees associated with ADUs are comprised of three types: 

• Planning Application Fee: Fee charged to review ADU plans for compliance with zoning standards, e.g. ADU size and location on a lot. This is a $142 fixed fee based on the staff time and resources required. 
• Building Fees: Plan check and permit fees to cover the cost of reviewing plans, issuing permits, and performing inspections. This is a variable fee, depending on building size and valuation. The average fees charged over the past three years are between $2,800 and $3,200 per unit.
• 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.
  
  Under the new State law, the City will be able to continue collecting the Planning Application Fee and Building Fees. Utility service/connection fees may not be collected for Junior ADUs and other ADUs that involve conversion of an existing structure. Impact fees may only be collected for ADUs of 750 s.f. or larger and may only be charged in an amount proportional to the primary dwelling.

There are three types of ADUs:

Junior: Unit is contained entirely within an existing single-family structure through conversion of existing living area. The unit includes an efficiency kitchen, which has cooking and food preparation facilities but may or may not have a sink. A junior ADU may have its own bathroom or may share a bathroom with the main dwelling.

Attached: Unit is comprised of an addition to the main dwelling and/or conversion of existing living area and may include conversion of an attached garage. The unit has a full kitchen and its own bathroom.

Detached: Unit is not attached to the main dwelling. Unit may be a new or rebuilt structure or conversion of all or a portion of an existing accessory structure, including a detached garage.