It is necessary to follow the zoning regulations for ADU construction in Simi Valley. Every zone has different provisions for ADU construction. Zoning rules determine where an ADU can be built. They also govern how much distance must be between the home and the ADU.
Simi Valley also has specific rules on the size of ADUs. Different size limits are set for single-family and multi-family properties. This ensures that the ADU is built in harmony with other homes in the area.
| Lot Size | Single-Family (Maximum Floor Area Allowed) | Duplex and Multi-Family (Maximum Floor Area Allowed) |
| 5,500 sq ft | 1,500 sq ft | 900 sq ft |
| 7,800 sq ft | 1,800 sq ft | 1,100 sq ft |
| 10,500 sq ft | 21,00 sq ft | 1,300 sq ft |
| 16,000 sq ft | 2,700 sq ft | 1,700 sq ft |
| 21,000 sq ft | 3,400 sq ft | 2,100 sq ft |
Simi Valley also has limits on the height of ADUs. ADU heights are capped to ensure construction complies with zoning regulations. Single-story ADUs can be up to 16 feet in height, while two-story ADUs may have a limit of 25 feet in some zones. Building Coverage
Land coverage is also important to consider for an ADU. In Simi Valley, the total area of the property and the size of the building determine how much area can be used for an ADU. Generally, the building area should not exceed 50% of the total area of the property.
The location of the ADU should be right so that it matches with the rest of the property. ADUs are usually built at the back or side of the main house. This ensures that privacy is maintained and there is no obstruction to other features of the property.
Single-Family Homes:
Duplexes and Multi-family:
The exterior design of the ADU is also important to take into account. It should match with the main house and maintain community aesthetics. It is best if the design of the roof, walls and windows matches the original style of the property.
Parking is also provided for ADUs in Simi Valley. Additional parking space may be required to build an ADU. If the ADU is separate from the main house, a parking space is a must. Also, parking must be installed according to the rules of the property.
ADUs have certain setback and buffer zones as per the rules. ADU construction in Simi Valley requires a certain distance from the front, rear and sides. This distance ensures that the property is safe to build and the privacy of neighbors is maintained.
ADU construction in Simi Valley also requires a minimum lot area. ADU construction in RF zones is allowed according to the size of the property.
| Zone | Minimum Lot Area |
| R-20 | 6,000 sq. ft. |
| R-10 | 8,500 sq. ft. |
| R-7 | 11,000 sq. ft. |
| R-5 | 16,000 sq. ft. |
| R-2.5 | 21,000 sq. ft. |
ADUs require connection to basic utilities like water, electricity and gas. These connections are planned to connect the ADU to the main house in Simi Valley. Proper connections not only provide convenience, but they also make the construction compliant with legal standards. While installing connections to these facilities, it is important to ensure that there is adequate supply of water and electricity.
It is important to obtain permission from the concerned departments before making connections for utilities. There may also be additional charges for these connections, which may vary according to the area and construction.
Fire safety is a must for ADU construction in Simi Valley. ADUs must have smoke detectors, fire alarms, and other fire prevention measures. Along with this, fireproof materials are also used in construction.
There are special rules for using an ADU as a short-term rental in Simi Valley. It is important that the owner himself is residing in the property. ADUs can also be used for commercial activities, but local rules must be followed.
ADU construction must follow the building codes in Simi Valley. These codes ensure that the ADU is safe and structurally sound. The quality and durability of construction is checked under the building codes.
A permit is required for ADU construction in Simi Valley. It is illegal to carry out construction work without the correct permit. Necessary documents and fees have to be submitted to obtain the permit.
| Permit Type | Cost |
| Building Permit | $2,500 – $5,500 |
| Electrical Permit | $280 – $550 |
| Plumbing Permit | $250 – $450 |
| Mechanical Permit | $150 – $300 |
| Demolition Permit | $100 – $200 |
| Landscaping Permit | $50 – $100 |
There are some specific property requirements for ADU construction. In Simi Valley, ADU construction is allowed depending on the size and location of the property. The property’s minimum lot size, zoning rules, and other conditions apply.
ADUs require proper parking. ADUs in Simi Valley may require additional parking. The parking space must be built without affecting other parts of the property.
ADU construction requires a certain distance (setback) from the front side. In Simi Valley, front setbacks are allowed to build so that the balance and beauty of the property is maintained. Front setbacks ensure that the ADU is located a certain distance from the main road, thereby maintaining security and privacy.
Side and rear setbacks are required for ADU construction in Simi Valley. Side setbacks ensure that enough space is left on the sides of the house. Rear setbacks ensure that the ADU is located at a safe and correct distance in the rear. This also protects the structure of the property and the privacy of the neighbor.
Open spaces and backyards also play an important role in ADU construction in Simi Valley. It is important to ensure that enough open space is left even after building the ADU. The backyard space should be utilized properly so that the home’s atmosphere remains open and airy.
Only certain properties are considered eligible for ADU construction. ADUs in Simi Valley require the right size and zoning of the property. If your property meets the minimum standards, you can build an ADU.
Properties in Simi Valley that conform to these standards are considered eligible for ADU. Apart from this, the location of the property and its amenities are also taken into consideration. If your property meets all these conditions, then permission to build an ADU can be obtained.
Multifamily properties
JADU (Junior Accessory Dwelling Unit) are small-sized ADUs in Simi Valley. It is a small unit inside the house, with limited amenities. It is usually suitable for a small family or personal use.
Some ADU designs in Simi Valley are pre-approved. These designs are in accordance with local rules and standards, making the construction process faster and easier. Choosing a pre-approved design can save you both time and money at the beginning of construction.
Pre-approved ADU designs in Simi Valley can be customized to your needs. Under this process, you only have to apply for the permit and everything else can be done under the already set standards.
Start your ADU project today. Follow all the necessary rules and guidelines to build an ADU in Simi Valley. ADUs increase the value and utility of your home, making your life more convenient.
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 Simi Valley 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 Simi Valley 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.
