Special zoning regulations apply to ADU construction in Thousand Oaks. Forming ADUs is allowed in residential areas, but there are some restrictions. Different rules apply in each zone. We must first find out the zone of our property. After this, it is necessary to follow the specific rules of that zone. Zoning information can be obtained from the Municipal Corporation.
| Lot Size | Single-Family (Maximum floor area) | Duplex and Multi-Family (Maximum floor area) |
| 4,800 | 1,100 sq ft | 750 sq ft |
| 7,200 | 1,400 sq ft | 950 sq ft |
| 9,600 | 1,700 sq ft | 1,150 sq ft |
| 14,400 | 2,300 sq ft | 1,550 sq ft |
| 19,200 | 2,900 sq ft | 1,900 sq ft |
Determination of the maximum height of the ADU in Thousand Oaks is very important. The height of the ADU should be lower than the main building. Separately made ADUs can have a maximum height of up to fifteen feet. The height of the connected ADU should not exceed the main building. To measure height, the distance from the ground to the topmost point of the roof is measured.
It is important to know the total building coverage before the construction of the ADU. Only a maximum of forty percent of the total area of the plot can be used for the building. This boundary includes both the main building and the ADU. Proper management of open space is essential. It is necessary to leave enough space for greenery and parking.
The location of the ADU should be chosen carefully. It is best to construct ADU behind or next to the main building. The ADU cannot be made on the front. It is important to maintain a proper distance from the neighbor’s house. Select the location keeping in mind the convenience of drainage and utility connections.
Single-Family Homes:
Duplexes and Multi-family:
The exterior design of the ADU should match the main building. Select the color, texture and building material accordingly. The roof design and styling of the windows should resemble the main building. Use the same finish on the exterior walls. Make ADU beautiful with landscaping and take care of the privacy of neighbors.
Additional parking is necessary for ADU at Thousand Oaks. A one-bedroom ADU needs a parking space. Two parking spaces are required for two or more bedrooms. Parking spaces should measure at least nine feet in width and twenty feet in length. Garages or carports can also be constructed.
Setback rules are very important for ADUs in our city. A setback of at least twenty feet is required at the front. A setback of five feet will have to be kept on the side and ten feet on the back. These rules have been made keeping privacy and security in mind. A buffer zone can be created by planting trees in the setback.
Thousand Oaks has a rule of minimum lot area for RF zones. The lot size should be sufficient to make an ADU. The size of the ADU will be limited on small lots. There will be more options available on larger lots. Keep setbacks and open space in mind when calculating the lot area.
| zone | Minimum Lot Area |
| R-18 | 4,800 sq. ft. |
| R-9 | 7,200 sq. ft. |
| R-6 | 9,600 sq. ft. |
| R-4 | 14,400 sq. ft. |
| R-2 | 19,200 sq. ft. |
It is very important to arrange proper utility connections for ADUs. Separate connections may have to be taken for water, electricity and sewer. The connection to the main building may need to be upgraded. Make a plan by contacting utility companies beforehand. Determine the meter and pipeline location carefully.
Utility connections require special permits. New meters and panels may have to be installed for electricity. Arrange separate pipelines and meters for water. Special attention must be taken to the slope for sewer connection. It is important to follow the safety rules for the gas line.
Many special provisions will have to be made in ADU for fire safety. It is mandatory to install smoke detectors and carbon monoxide alarms. There should be an emergency exit. Ensure availability of fire extinguisher. The size of the windows should be suitable for emergency evacuation. Follow the fire department’s rules.
Thousand Oaks has some restrictions on using ADUs for short-term rentals. Rent for a period less than thirty days is not permitted. Special permits will have to be obtained for home occupation. Business activities should not disturb neighbours. It is important to take special care of parking and movement.
ADU construction is required to comply with California building codes. All building materials must conform to standards. Get the electrical and plumbing work done by licensed contractors. Make an appointment on time for inspections. Strictly follow safety standards.
It is mandatory for ADUs to obtain a building permit. Submit all the necessary documents on time. Get the plan and drawing prepared in detail. The permit process can take about six to eight weeks. Pay all fees on time.
| Type of Permit | cost |
| Building Permits | $2,500 – $5,500 |
| Electrical Permit | $300 – $550 |
| Plumbing Permit | $250 – $450 |
| Mechanical Permit | $200 – $350 |
| Demolition Permit | $150 – $250 |
| Landscaping Permit | $75 – $150 |
To build an ADU in Thousand Oaks, some basic property conditions must be met. The slope of the ground should not exceed fifteen percent. It is necessary to have proper drainage of water. Additional safety measures will be required in the earthquake and flood zones. Plan the construction by getting the soil tested.
Separate parking will have to be arranged for ADU. A car space is a must for a bedroom ADU. The size of the car parking should be nine feet wide and nineteen feet long. Access to the parking lot needs to be clean and accessible. Garages or covered parking can also be constructed.
It is necessary to leave a setback of twenty feet for the ADU from the road side. ADU cannot be constructed in front of the main building. Make good landscaping arrangements in the front yard. Parking is not allowed in the setback area. Follow the rules to keep Street View engaging.
It is necessary to leave a setback of at least five feet in the side. A setback of ten feet at the back is a must. Additional setbacks may be required on corner lots. Utility connections and air conditioning units can be installed in the setback. Take special care of the neighbor’s privacy.
Proper management of open space and back courtyard is essential. At least thirty percent of the total area of the plot must be kept open. Leave space for children to play and garden. Make proper arrangements for the flow of rainwater. Plant trees to maintain greenery.
Not every residential property in Thousand Oaks qualifies for an ADU. The zone and size of the property should conform to the standards. A minimum lot size is required according to the zone. The property should have adequate open space and parking facilities. Availability of utility connection is also important.
Additional rules apply for properties with special circumstances. Special clearance will be required in flood and earthquake zones. Historic buildings have different rules for ADUs. Slope and soil testing is necessary in hilly areas. Extra care must be taken in environmentally sensitive areas.
Multifamily properties
The Junior ADU is built inside the main house itself. Its size cannot exceed five hundred square feet. Basic kitchen facilities are essential. The bathroom can be shared with the main house. Arrange separate entrances. No additional parking is required.
Thousand Oaks City has approved some standard ADU designs in advance. Using these designs speeds up the permit process. One and two bedroom options are available in pre-approved designs. All the necessary facilities are already included in them. The construction cost can be easily estimated.
Small changes can be made to the standard design as per requirement. The design price is decided by the City. Adherence to all the rules of the building code is ensured in advance. Construction saves time and money. Full details of the pre-approved design are available on the city’s website.
We at ADU Builders CA will help you successfully complete your ADU project. Our expert team keeps full knowledge of all the rules and requirements. We will guide you through the entire process from planning to construction. Special attention will be paid to the budget and time frame. Contact us today and make your dream ADU come true.
Fire sprinklers are only required if the primary dwelling also has them.
ADUs typically require a minimum setback of 4 feet from property lines.
Separate utility connections are optional but not mandatory for most ADUs.
The checklist includes design review, site plans, structural plans, permits, and financing.
You need site plans, floor plans, construction details, and a permit application.
Inspections typically include foundation, framing, plumbing, electrical, and final review.
Work with licensed professionals to design and construct your ADU to code.
You may need to revise and resubmit plans to the Thousand Oaks planning office.
Submit complete and accurate documents and work with professionals to avoid delays.
ADUs under 750 sq. ft. are exempt from impact fees.
Yes, it includes checking structure, utilities, and obtaining conversion permits.
Yes, ADUs must meet height, size, and setback requirements, and their design should complement the primary dwelling.
Yes, but you need to ensure the ADU fits within allowable lot coverage and setback rules.
ADUs must comply with California Building Codes, including foundation, framing, insulation, plumbing, and electrical requirements.
Yes, ADUs must comply with California Energy Code (Title 24) and include energy-efficient windows, insulation, and appliances.
You must submit a revised plan to the Thousand Oaks Building Department and may incur additional fees or inspections.
Yes, ADUs near high-noise areas (e.g., busy roads) must include soundproofing measures such as double-glazed windows.
Yes, you can appeal to the city’s Planning Commission or seek adjustments to meet requirements.
Lot coverage varies by zoning but generally allows for up to 50% of the lot to be developed, including the primary dwelling and ADU.
