Union City ADU Zoning And Building Standards
Union City’s Accessory Dwelling Unit (ADU) zoning and building standards provide a comprehensive guide for homeowners looking to add an ADU to their property. These regulations ensure that ADUs are built safely, efficiently, and in compliance with local laws, while also providing housing options for the community.
Our team of experts is well-versed in Union City’s ADU zoning and building standards. We can guide you through the entire process, from understanding the requirements to designing and constructing your ADU, ensuring a smooth and stress-free experience.
Property Requirements
Union City has specific requirements for properties that wish to add an ADU. These requirements vary depending on the zoning of the lot, such as single-family, duplex, or multi-family. It’s essential to understand these requirements before beginning the ADU process.
Building Size
- Single-Family Zoned Lots:
Single-family zoned lots in Union City are permitted to have one ADU and one Junior ADU (JADU). The ADU can be either attached to the primary dwelling or detached, while the JADU must be located within the primary dwelling.
- Duplex Family Zoned Lots:
Duplex family zoned lots in Union City are allowed to have one ADU per unit, for a total of two ADUs on the property. These ADUs can be either attached or detached from the primary dwellings.
- Multi-Family Zoned Lots:
Multi-family zoned lots in Union City can have up to two detached ADUs or up to 25% of the existing unit count in the form of converted non-livable spaces.
- Attached ADUs: Attached ADUs are connected to the primary dwelling and must meet specific size and design requirements.
- Detached ADUs: Detached ADUs are separate structures from the primary dwelling and must adhere to setback and size regulations.
Owner-occupancy
In Union City, owner-occupancy is not required for properties with ADUs. This means that both the primary dwelling and the ADU can be rented out, providing more flexibility for homeowners.
Number of Units Allowed
The number of ADUs allowed on a property in Union City depends on the zoning. Single-family lots can have one ADU and one JADU, duplex lots can have one ADU per unit, and multi-family lots can have up to two detached ADUs or 25% of the existing unit count.
Union City Building Height
Union City has specific ADUs building height requirements. These requirements ensure that ADUs are built to a safe and appropriate height while maintaining the character of the neighborhood.
- Single-family: Single-family zoned lots in Union City have a maximum building height of 16 feet for detached ADUs and the same height as the primary dwelling for attached ADUs. This allows for the construction of comfortable and functional ADUs without overwhelming the property.
- Duplex family: Duplex family zoned lots in Union City have the same building height requirements as single-family lots. Detached ADUs can have a maximum height of 16 feet, while attached ADUs must match the height of the primary dwellings.
- Multi-family: Multi-family zoned lots in Union City have a maximum building height of 16 feet for detached ADUs. Converted non-livable spaces must comply with the existing building height of the primary structure.
Union City Building Size
Union City has specific building size requirements for ADUs, which vary depending on the zoning of the property. These requirements ensure that ADUs are built to an appropriate size for the lot while still providing comfortable living spaces.
- Single-Family Freedom: Single-family zoned lots in Union City have a maximum ADU size of 850 square feet for studio and one-bedroom units, and 1,000 square feet for units with two or more bedrooms. JADUs must not exceed 500 square feet.
- Duplex house: Duplex family zoned lots in Union City have the same ADU size limits as single-family lots. Each ADU can be up to 850 square feet for studio and one-bedroom units, and 1,000 square feet for units with two or more bedrooms.
- Multi-Family Mix: Multi-family zoned lots in Union City have a maximum ADU size of 850 square feet for studio and one-bedroom units, and 1,000 square feet for units with two or more bedrooms. Converted non-livable spaces must not exceed 25% of the existing unit count.
Fire Safety Regulations
Union City has strict fire safety regulations for ADUs to ensure the safety of occupants. These include requirements for fire-resistant construction materials, smoke alarms, carbon monoxide detectors, and adequate emergency access.
Parking
Union City requires one parking space per ADU, which can be provided as tandem parking on an existing driveway. However, parking requirements may be waived if the ADU is located within half a mile of public transit or in an architecturally and historically significant district.
Utility Connections
ADUs in Union City must have separate utility connections for water, sewer, gas, and electricity. This ensures that each unit has its own metered services and the primary dwelling is not overburdened by the additional usage.
Setbacks
Setback requirements for ADUs in Union City vary depending on the zoning and type of ADU. Detached ADUs must be located at least 4 feet from the side and rear property lines, while attached ADUs must meet the same setback requirements as the primary dwelling.
Zoning Regulations
Union City’s zoning regulations for ADUs ensure that these units are built in appropriate locations and maintain the character of the neighborhood. The specific regulations differas per zones of the property.
Single Family
Single-family zoned lots in Union City are permitted to have one ADU and one JADU, provided they meet all size, height, and setback requirements. The ADU can be either attached or detached from the primary dwelling.
Duplex Family
Duplex family zoned lots in Union City are allowed to have one ADU per unit, for a total of two ADUs on the property. These ADUs must meet the same size, height, and setback requirements as single-family lots.
Multi-Family
Multi-family zoned lots in Union City can have up to two detached ADUs or up to 25% of the existing unit count in the form of converted non-livable spaces. These ADUs must comply with all size, height, and setback regulations.
RF Zone Minimum Lot Area in Union City
In Union City 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: Minimum lot size of 20,000 square feet, perfect for spacious ADUs and outdoor living spaces.
- RF-30: Minimum lot size of 30,000 square feet, ideal for larger ADUs and expansive gardens.
- RF-40: Minimum lot size of 40,000 square feet, offering the ultimate in space and privacy for your ADU.
Room Specifications
The room specifications table provides a quick reference for the minimum requirements for each room type in an ADU. This ensures that your ADU is designed to meet all necessary living standards.
| Room Type | Specifications |
| Bathroom | – Minimum 30 square feet |
| – Shower or bathtub | |
| – Sink | |
| – Toilet | |
| – Ventilation | |
| Kitchen | – Minimum 50 square feet |
| – Sink | |
| – Refrigerator | |
| – Cooking appliance | |
| – Counter space | |
| Sleeping Areas | – Minimum 70 square feet |
| – Egress window or door | |
| – Heating | |
| – Ventilation | |
| – Ceiling height 7’6″ | |
| Storage | – Minimum 20 square feet |
| – Easily accessible | |
| – Dry and pest-free | |
| – Separate from living areas | |
| – Lockable |
Union City Requirements
Union City has specific requirements for each type of ADU, including detached ADUs, attached ADUs, and JADUs. These requirements ensure that each ADU is built to the appropriate standards and meets the needs of the occupants.
Detached ADU Union City: Detached ADUs in Union City must be located on the same lot as the primary dwelling and have a maximum size of 850 square feet for studio and one-bedroom units, and 1,000 square feet for units with two or more bedrooms. They must also meet setback and height requirements.
Attached ADU Union City: Attached ADUs in Union City must be connected to the primary dwelling and meet the same setback requirements. They can have a maximum size of 850 square feet for studio and one-bedroom units, and 1,000 square feet for units with two or more bedrooms.
JADU Union City: JADUs in Union City must be located within the primary dwelling and have a maximum size of 500 square feet. They must also have an efficiency kitchen, which includes a sink, refrigerator, and cooking appliance.
Rental Requirements
When renting out an ADU in Union City, there are several requirements that both the landlord and tenant must meet. These requirements help ensure a fair and transparent rental process.
- Proof of income: Tenants must provide proof of income to demonstrate their ability to pay rent, typically in the form of pay stubs or tax returns.
- Credit score: Landlords may require a minimum credit score to assess the tenant’s financial responsibility and likelihood of paying rent on time.
- Rental history: Tenants should be prepared to provide references from previous landlords to demonstrate their reliability as a renter.
- Application fee: Landlords may charge a reasonable application fee to cover the cost of processing the tenant’s application.
- Security deposit: Tenants must pay a security deposit, typically equal to one month’s rent, to cover potential damages to the property.
- Proof of renter’s insurance: Landlords may require tenants to provide proof of renter’s insurance to protect their personal belongings and cover potential liabilities.
- Pet policy: Landlords should clearly state their pet policy, including any restrictions on the type, size, or number of pets allowed.
- Smoking policy: Landlords should specify their smoking policy, indicating whether smoking is permitted on the property and any designated smoking areas.
Development Standards For Union City ADU
The Development Standards table provides an overview of the specific requirements for each type of ADU in Union City. This table is a quick reference guide for understanding the key regulations.
| ADU Types | Development Standards Specifications |
| Single-family | – Max 1 ADU & 1 JADU |
| – 850 sqft (studio/1-bed) | |
| – 1,000 sqft (2+ bed) | |
| – 16 ft height (detached) | |
| – Same setbacks as primary | |
| Duplex | – Max 1 ADU per unit |
| – 850 sqft (studio/1-bed) | |
| – 1,000 sqft (2+ bed) | |
| – 16 ft height (detached) | |
| – Same setbacks as primary | |
| Multi-family | – Max 2 detached ADUs |
| – 25% of units (converted) | |
| – 850 sqft (studio/1-bed) | |
| – 1,000 sqft (2+ bed) | |
| – 16 ft height (detached) | |
| Junior ADUs (JADUs) | – Max 500 sqft |
| – Within primary dwelling | |
| – Efficiency kitchen | |
| – Separate entrance | |
| – Owner occupancy required |
Union City Property Designations For ADU
Before building an ADU in Union City, it’s essential to understand any property designations that may impact the construction process or the ADU’s design.
- Flood zones: Properties located in flood zones may require additional permits and building requirements to mitigate the risk of flood damage.
- Geohazard zones: Properties in geohazard zones, such as areas prone to landslides or earthquakes, may have specific building requirements to ensure the safety and stability of the ADU.
- Easements: Properties with easements may have restrictions on where an ADU can be located to avoid interfering with utility lines, access roads, or other designated areas.
ADU Permit Requirements And Fees
Building an ADU in Union City requires various permits and fees to ensure compliance with local regulations and safety standards. The following permits are typically required:
- Building Permit: A Building Permit is required for the construction of an ADU to ensure that the structure meets all safety and building codes.
- Electrical Permit: An Electrical Permit is needed to ensure that all electrical work in the ADU is performed safely and up to code.
- Plumbing Permit: A Plumbing Permit is required to ensure that all plumbing work in the ADU is done correctly and meets local regulations.
- Other Permits: Depending on the specifics of your ADU project, additional permits may be required, such as a Mechanical Permit for HVAC work or a Grading Permit for site preparation.
