San Jose ADU Zoning And Building Standards
San Jose offers a fantastic opportunity for homeowners to build Accessory Dwelling Units (ADUs) on their properties. With the right guidance and understanding of local zoning and building standards, you can create additional living space, generate rental income, or provide housing for family members.
Our team of experienced professionals is here to guide you through the process of building an ADU in San Jose. We’ll help you navigate the zoning regulations, building standards, and permit requirements to ensure a smooth and successful project.
Property Requirements
Before starting your ADU project, it’s essential to understand the property requirements in San Jose. These requirements vary depending on the zoning of your lot, whether it’s single-family, duplex, or multi-family.
Building Size
The allowed building size for your ADU depends on the zoning of your property. Single-family zoned lots have the most flexibility, while duplex and multi-family zoned lots have specific size limitations.
- Single-Family Zoned Lots:
Single-family zoned lots in San Jose allow for the most flexibility in terms of ADU size. You can build an ADU up to 1,200 square feet or 50% of the primary dwelling’s size, whichever is less.
- Duplex Family Zoned Lots:
For duplex family zoned lots, the maximum ADU size is 800 square feet or 50% of the primary dwelling’s size, whichever is less. This allows for a comfortable living space while maintaining the character of the neighborhood.
- Multi-Family Zoned Lots:
Multi-family zoned lots have the most restrictive ADU size limitations. The maximum allowed size is 600 square feet or 50% of the primary dwelling’s size, whichever is less.
- Attached ADUs:
Attached ADUs are limited to 50% of the primary dwelling’s size, up to a maximum of 1,200 square feet.
- Detached ADUs:
Detached ADUs can be up to 1,200 square feet, regardless of the primary dwelling’s size.
Owner-occupancy
In San Jose, owner-occupancy is not required for properties with an ADU. This means that you can build an ADU and rent out both the primary dwelling and the ADU if desired.
Number of Units Allowed
The number of ADUs allowed on a property depends on the zoning. Single-family and duplex zoned lots can have one ADU and one Junior ADU (JADU), while multi-family zoned lots can have up to two detached ADUs.
San Jose Building Height
The allowed building height for your ADU varies based on the zoning of your property. It’s essential to understand these limitations to ensure your ADU complies with local regulations.
- Single-family: Single-family zoned lots allow for a maximum ADU height of 20 feet for attached ADUs and 25 feet for detached ADUs. This provides ample space for a comfortable living area.
- Duplex family: Duplex family zoned lots have a maximum ADU height of 18 feet for attached ADUs and 20 feet for detached ADUs. These height limitations help maintain the character of the neighborhood.
- Multi-family: Multi-family zoned lots allow for a maximum ADU height of 16 feet for both attached and detached ADUs. This ensures that the ADU does not overwhelm the existing structures on the property.
San Jose Building Size
The allowed building size for your ADU is determined by the zoning of your property. Each zoning type has specific size limitations to ensure that the ADU fits seamlessly into the neighborhood.
- Single-Family Freedom: Single-family zoned lots offer the most flexibility in terms of ADU size. You can build an ADU up to 1,200 square feet or 50% of the primary dwelling’s size, whichever is less.
- Duplex house: For duplex family zoned lots, the maximum ADU size is 800 square feet or 50% of the primary dwelling’s size, whichever is less. This provides a comfortable living space while maintaining the character of the neighborhood.
- Multi-Family Mix: Multi-family zoned lots have the most restrictive ADU size limitations. The maximum allowed size is 600 square feet or 50% of the primary dwelling’s size, whichever is less.
Fire Safety Regulations
Fire safety is a crucial consideration when building an ADU. Your ADU must have smoke alarms, carbon monoxide detectors, and a fire extinguisher. Additionally, the ADU must have a separate entrance and no internal connection to the primary dwelling.
Parking
In San Jose, parking requirements for ADUs have been relaxed to encourage their development. In most cases, no additional parking is required for an ADU. However, if your property is located in a specific plan area or overlay zone, parking requirements may vary.
Utility Connections
Your ADU must have separate utility connections for water, sewer, and electricity. This ensures that the ADU is independent from the primary dwelling and can be easily metered for billing purposes.
Setbacks
Setbacks are the minimum required distances between your ADU and the property lines. In San Jose, the setback requirements vary based on the zoning of your property and the type of ADU (attached or detached).
Zoning Regulations
Zoning regulations determine what types of structures and uses are allowed on a property. In San Jose, the zoning regulations for ADUs vary based on the type of property.
Single Family
Single-family zoned lots have the most flexibility in terms of ADU development. You can build an attached or detached ADU, as well as a Junior ADU (JADU).
Duplex Family
Duplex family zoned lots allow for one ADU and one JADU. The ADU can be attached or detached, but must meet the specific size and height limitations for this zoning type.
Multi-Family
Multi-family zoned lots can have up to two detached ADUs. These ADUs must meet the size and height limitations for multi-family zoned properties.
RF Zone Minimum Lot Area In San Jose
In San Jose RF Zone, minimum lot sizes range from spacious single-family homes (RF-20) to sprawling estate properties (RF-40), ensuring ample space for your ADU and lifestyle.
- RF-20: The minimum lot area for an RF-20 zoned property is 20,000 square feet, providing ample space for a detached or attached ADU and outdoor living areas.
- RF-30: Properties zoned RF-30 require a minimum lot area of 30,000 square feet, offering even more room for your ADU and landscaping.
- RF-40: The most spacious option, RF-40 zoned lots must have a minimum area of 40,000 square feet, perfect for those seeking a more expansive property and ADU.
Room Specifications
When designing your ADU, it’s essential to consider the specifications for each room to ensure comfort, functionality, and compliance with local building codes.
| Room Type | Specifications |
| Bathroom | – Minimum 30 square feet – Ventilation required – Waterproof flooring – GFCI outlets – Low-flow fixtures |
| Kitchen | – Minimum 50 square feet – Sink, stove, and refrigerator required – Adequate counter space – Electrical outlets every 4 feet – Durable, easy-to-clean flooring |
| Sleeping Areas | – Minimum 70 square feet – Closet space required – Egress window or door – Smoke and carbon monoxide detectors – Comfortable flooring |
| Storage | – Minimum 20 square feet – Easily accessible – Well-ventilated – Sturdy shelving – Moisture-resistant materials |
San Jose Requirements
When building an ADU in San Jose, there are specific requirements you must meet depending on the type of ADU you’re constructing. These requirements ensure that your ADU is safe, habitable, and complies with local regulations.
Detached ADU San Jose: Detached ADUs in San Jose must be located in the rear or side yard and can be up to 1,200 square feet. They must also meet setback requirements and have a maximum height of 25 feet.
Attached ADU San Jose : Attached ADUs in San Jose can be up to 50% of the primary dwelling’s size, with a maximum of 1,200 square feet. They must have a separate entrance and no internal connection to the primary dwelling.
JADU San Jose: Junior ADUs (JADUs) in San Jose are limited to 500 square feet and must be located within the primary dwelling. They require a separate entrance and an efficiency kitchen but can share bathroom facilities with the primary dwelling.
Rental Requirements
If you plan to rent out your ADU, there are several requirements you should be aware of to ensure a smooth and legal rental process.
- Proof of income: Landlords typically require prospective tenants to provide proof of income, such as pay stubs or tax returns, to ensure they can afford the rent.
- Credit score: Many landlords also check a tenant’s credit score to assess their financial responsibility and likelihood of paying rent on time.
- Rental history: Providing references from previous landlords can help demonstrate a tenant’s reliability and trustworthiness.
- Application fee: Landlords may charge an application fee to cover the cost of background and credit checks.
- Security deposit: Tenants are usually required to pay a security deposit, which can be used to cover any damages or unpaid rent at the end of the lease.
- Proof of renter’s insurance: Some landlords may require tenants to have renter’s insurance to protect their personal belongings and provide liability coverage.
- Pet policy: Landlords should clearly state their pet policy, including any breed or size restrictions and additional pet rent or deposits.
- Smoking policy: It’s important to specify whether smoking is allowed in the ADU and any designated smoking areas on the property.
Development Standards For San Jose ADU
The development standards for ADUs in San Jose vary depending on the type of ADU and the zoning of the property. These standards ensure that ADUs are built safely and in compliance with local regulations.
| ADU Types | Development Standards Specifications |
| Single-family | – Maximum size: 1,200 sq. ft. or 50% of primary dwelling – Maximum height: 20 feet (attached), 25 feet (detached) – Setbacks: 4 feet from side and rear property lines – Parking: None required – Owner-occupancy: Not required |
| Duplex | – Maximum size: 800 sq. ft. or 50% of primary dwelling – Maximum height: 18 feet (attached), 20 feet (detached) – Setbacks: 4 feet from side and rear property lines – Parking: None required – Owner-occupancy: Not required |
| Multi-family | – Maximum size: 600 sq. ft. or 50% of primary dwelling – Maximum height: 16 feet (attached and detached) – Setbacks: 4 feet from side and rear property lines – Parking: None required – Owner-occupancy: Not required |
| Junior ADUs (JADUs) | – Maximum size: 500 sq. ft. – Location: Within primary dwelling – Kitchen: Efficiency kitchen required – Bathroom: May share with primary dwelling – Parking: None required |
San Jose Property Designations For ADU
When planning your ADU, it’s crucial to consider any special property designations that may affect the development process.
- Flood zones: If your property is located in a flood zone, you may need to take additional measures to protect your ADU from potential flood damage and comply with specific building requirements.
- Geohazard zones: Properties in geohazard zones, such as those with a high risk of earthquakes or landslides, may require additional engineering and safety measures when constructing an ADU.
- Easements: Be aware of any easements on your property, such as utility or access easements, which may limit where you can build your ADU or require additional permissions.
ADU Permit Requirements And Fees
Before starting construction on your ADU, you’ll need to obtain the necessary permits from the City of San Jose. Each permit has associated fees, which can vary depending on the scope of your project.
- Building Permit: A building permit is required for all ADU construction, ensuring that your project meets local building codes and safety standards. Fees vary based on the size and complexity of your ADU.
- Electrical Permit: If your ADU requires new or upgraded electrical work, you’ll need to obtain an electrical permit. Fees are based on the scope of the electrical work being performed.
- Plumbing Permit: A plumbing permit is necessary for any new or modified plumbing in your ADU. Fees are calculated based on the number and type of plumbing fixtures being installed.
- Other Permits: Depending on your ADU design, you may need additional permits, such as a mechanical permit for HVAC systems or a grading permit for significant changes to the land.
Design Your Dream ADU Today!
With a clear understanding of San Jose’s ADU zoning and building standards, you’re well on your way to creating the perfect accessory dwelling unit for your property. Whether you’re looking to provide housing for family members, generate rental income, or simply expand your living space, an ADU can be a valuable addition to your home. Start designing your dream ADU today and take the first step towards making it a reality!