Everything about building Accessory Dwelling Units in Thousand Oaks, CA
Check your property's zoning, browse designs & get contractor estimates for your ADU project:
Last Updated 08/14/21
City Hint: The City of Thousand Oaks permitted a total of 49 ADU projects in the past year of 2020.
Number of ADUs allowed:
1 junior and 1 attached or detached ADU are allowed on single-family lots. Multifamily lots may have 2 detached ADUs and attached ADUs equal to 25% of the multi-family units.
Types of ADUs allowed:
Detached ADU, Attached ADU, Junior ADU are allowed. ADUs may be new construction or converted from existing space. JADUs must be converted from existing space.
Single family and multi-family residential properties will not be subject to the minimum lot size of the underlying zoning district or by ordinance for ADU projects. ~ Updated: State Law AB-68
o Junior ADU: 500 square feet
o Attached ADU: 50% of primary residence area
o Detached ADU: 850 square feet for a studio or 1- bedroom unit and 1,000 square feet for a 2- bedroom or larger unit
Junior and attached ADUs are subject to the same setbacks as the primary residence. Side and rear setbacks for detached ADUs are 4 ft.
One parking space is required for attached and detached ADUs with 1 or more bedrooms. The parking may be uncovered and may be tandem in a driveway. No parking is required for studio units or junior ADUs. ADUs are exempt from parking requirements in certain situations Parking is not required for an ADU meeting any of the following criteria:
o Located within ½ mile of public transit
o Located in an architecturally and historically significant district
o Located within one block of car share vehicle
o Located within an existing structure that has been expanded by no more than 150 square feet
Fire sprinklers are required if the primary residence has fire sprinklers and may be required otherwise per the Fire Department under certain conditions
Shape, materials and style:
i) Materials and colors of exterior walls, roof, eaves, windows, and doors of an ADU must match those of the primary dwelling.
ii) Roof slope of ADU must match the dominant roof slope of the primary dwelling.
iii) ADU must have an independent exterior entrance separate from the primary dwelling.
Junior and attached ADUs have the same maximum height as the primary dwelling unit. Detached ADUs are limited to a maximum height of 16 feet
One of the residential units on the lot shall be occupied by the property owner. Attached or detached accessory dwelling units shall not be located within one hundred (100) feet of any publicly or privately-owned natural open space. Attached or detached accessory dwelling units shall be reviewed ministerially. The accessory dwelling unit must contain at minimum an efficiency kitchen.
The accessory dwelling unit shall not be located in the front yard area between the primary residence and the street.
Number of Bedrooms:
Attached or detached accessory dwelling units shall be reviewed ministerially.
Owner-occupancy will not be required for new Accessory Dwelling Unit (ADU)s (conversion and new construction) built between 2020 and 2025. ~ SB13
Local health officer approval where a private sewage disposal system is being used, if required. (State requirements)
*** Beginning in 2020, according to state law, all residential zoning districts, including single-family and multi-family, are allowed to build Accessory Dwelling Units. ***
Residential Building Code:
The California Building Code (CBC) 2019 is adopted.
ADU Design Library
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ADU Model 676 sqft
26 ft x 26 ft
ADU Model 700 sqft
35 ft x 20 ft
ADU Model 400 sqft
20 ft x 20 ft
This estimate is based on recently completed projects in the area and is inclusive of all typical soft costs such as permitting, design and engineering fees.
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