Duarte ADU Checklist

Zoning Regulations in Duarte

Duarte’s zoning regulations set rules for ADU placement, size, and design, aligning with urban planning goals. A key stipulation limits the ADU’s length to 50% of the main dwelling or 1,200 square feet, whichever is smaller.

ADU Size Limitations

Duarte’s ADU size limitations are primarily determined by the type of dwelling the ADU is attached to (single-family, duplex, or multi-family) and the overall lot size. There are no minimum lot size requirements for building an ADU in Duarte.

Lot Size	Single-Family (Maximum Floor Area Allowed)	Duplex (Maximum Floor Area Allowed)	Multi-Family (Maximum Floor Area Allowed)
Any	40% of Lot Size	60% of Lot Size	70% of Lot Size

ADU Height Limitations

Duarte allows ADUs up to 16 feet tall for detached units on single-family lots. The attached units can reach 25 feet. Height limits don’t apply to conversions within existing structures.

Building coverage

It depends on the type of dwelling they’re attached to: single-family homes allow 40% lot coverage, duplexes 60%, and multi-family dwellings 70%. Remember, these are percentages, not fixed square footage so the allowable size will vary based on your lot size.

Location

In Los Angeles County, Duarte welcomes Accessory Dwelling Units (ADUs) to add housing options and increase residential density. However, the location of your ADU depends on the type of property you have:

Single-Family Homes:

• It must be located on the rear or side yard of the main dwelling.
• Minimum setbacks from property lines apply 4 feet from the side and rear, potentially more from the front, depending on the specific location.
• Conversions of existing structures, like garages, are allowed within the main dwelling footprint.

Duplexes and Multi-family:

• It can be attached to the main dwelling, rear, or side yard.
• The same setback requirements as single-family homes apply.
• It may require additional review and approval for multiple ADUs on a single lot.
• Setback requirements might be adjusted based on the specific configuration and number of units involved.

Exterior details

They typically follow the same architectural style and materials as the primary dwelling, ensuring a cohesive and visually pleasing look. Expect to see details like matching rooflines, siding materials, and window styles.

Parking

Differ based on the type of dwelling and proximity to public transportation. Single-family homes typically need one extra parking space unless the ADU is within ½ mile of public transit. For duplexes and multi-family dwellings, parking needs vary depending on the number of units and access to public transit.

Setbacks and Buffer Zones

Must adhere to minimum setback requirements to ensure proper spacing and access. For single-family homes, expect a minimum 4-foot setback from side and rear property lines, with the front setback potentially larger depending on location. Duplexes and multi-family dwellings typically have larger allowed setbacks.

Minimum Lot Area (RF Zone)

For ADUs in Duarte, California’s RF (Residential Family) zoning districts, minimum lot area requirements vary based on the specific zoning designation

Zone	Minimum Lot Area
R-20	Not specified
R-10	7,500 sq. ft.
R-7	5,000 sq. ft.
R-5	3,500 sq. ft.
R-2.5	2,500 sq. ft.

Connection For Utilities

Duarte promotes sustainable, independent utilities for ADUs, prioritizing resource efficiency and cost-effectiveness. While new water and sewer connections may be needed, following city plumbing codes and regulations, existing connections from the main dwelling can sometimes be extended to the ADU. Thorough inspections and potential upgrades may be required.

Fire Safety

All ADUs need smoke detectors and carbon monoxide alarms in every bedroom and living area. ADUs over 800 sq ft must have sprinkler systems, with retrofitting recommended for existing units. Clear escape routes with outward-opening doors and unobstructed pathways to the outside are crucial.

Room Specifications

• Sleeping Areas: A minimum ceiling height of 7 feet and ample natural light and ventilation are necessary. It is important to ensure adequate closet space as well.
• Kitchen: A functional kitchen layout should have enough space for food preparation and essential appliances like a stovetop, sink, and refrigerator. Adequate countertop and cabinet space is also crucial to meet basic needs.
• Bathroom: A standard bathroom includes a toilet, sink, and shower/tub. However, specific situations may require grab bars and other accessible features. Ventilation and an efficient exhaust system are crucial for proper function.
• Storage: Built-in cabinets or designated storage areas are essential. Maximizing efficiency through vertical space utilization and creative storage solutions controls clutter, ensuring a comfortable and spacious feel.

Short-term Rentals and Home Occupations Regulations

Short-term rentals are prohibited, emphasizing long-term tenancy. Home occupations are allowed with conditions, like offering professional services, craft sales, or art studios within the dwelling. Restrictions seek to maintain the neighborhood’s residential character and limit non-family employees. Commercial vehicles and excessive equipment storage are not permitted.

Building Codes

The city follows the 2022 California Building Code, which includes regulations for accessibility, fire safety, and structural integrity. This means that smoke detectors, sprinkler systems for larger units, and clear escape routes are mandatory. Materials and construction practices must adhere to strict guidelines to ensure the safety and comfort of residents in ADUs.

ADU Permit Duarte Guidelines

They include rules on location, exterior details, fire safety, room specifications, lot area, utility connections, parking, and compliance with the 2022 California Building Code.

 

Permit Type	Cost
Building Permit	$1,500 – $5,000
Zoning Permit	$250 – $500
Plan Check	$500 – $2,000
Plumbing Permit	$150 – $500
Electrical Permit	$150 – $500
Mechanical Permit	$150 – $500
Tree Removal Permit	$50 – $250

Visit ADU Permits and Development in Duarte to know more.

Property Requirements

Duarte allows ADUs on most single-family properties with no minimum lot size requirement. However, the location and size of ADUs depend on the property’s zoning designation. Consult Duarte Planning Division for specific limitations and ensure ADU complies with city requirements.

Parking

Generally, single-family homes require one additional parking space unless the ADU is within ½ mile of public transit. Duplexes and multi-family dwellings have more nuanced parking needs based on the number of units and public transit access.

Front setbacks

Attached Accessory Dwelling Units (ADUs) typically require a minimum 4-foot setback, whereas detached units may require a greater distance. Nevertheless, specific regulations and potential exemptions may be applicable.

Side and rear setbacks

Single-family homes usually require a 4-foot minimum setback from side and rear property lines to allow for maintenance and emergency access and to avoid a cramped feeling. Duplexes and multi-family dwellings may have larger setback requirements based on unit configuration and development size. Depending on unique property features, exceptions or adjustments to these setbacks may be possible.

Open space and rear yards

Consider incorporating open space and outdoor elements in your ADU to enhance property value, create pleasant living spaces, and contribute to a more desirable community. Patios, decks, and small gardens can make a big difference in livability and appeal.

Properties That Qualify

Duarte promotes ADUs to boost housing options and foster community. Before planning your dream ADU, know who qualifies for a permit in Duarte. Most properties are eligible for ADU construction, regardless of lot size. Regulations depend on property type and zoning. Owner-occupancy is not required but encouraged for neighborhood stability.

Development Standards

Single-family

• Attached: You can convert an existing garage or other structure or add a new addition to your home. These units share walls and utilities with the main dwelling, offering a connected living experience. However, they must adhere to setback requirements and maintain a harmonious appearance with existing architecture.
• Detached: Offer more independence and privacy. They can be built on your property’s side or rear yard, providing a separate living space with its own entrance and outdoor area. These units have different regulations regarding setbacks and height limitations, blending seamlessly into the neighborhood while maintaining a comfortable distance from the main dwelling.

Duplex properties

• Attached: Like single-family homes, you can convert existing structures or add an extension to the duplex. However, the ADU cannot directly connect to both duplex units, so it should be attached to only one side to maintain the structure’s character. Setback requirements and size limitations may be stricter than single-family homes, so careful planning is necessary.
• Detached: This option allows more freedom for duplex owners. A detached ADU can be placed in the side or rear yard, with a minimum distance of 6 feet from the duplex for privacy. Keep in mind that there are setbacks and height restrictions.

Multifamily properties

• Attached: Connecting a new unit directly to the multi-family structure may be tempting, but Duarte guidelines generally prohibit it. Instead, attaching an ADU to a standalone garage or another existing structure on the property is usually preferred. However, the chosen location must maintain light and access for existing multi-family units. Noise mitigation and maintaining architectural harmony are crucial for multi-family properties.
• Detached: They can be placed on the side or rear yard, ensuring privacy and separation from the main building. However, setback and height limitations may apply based on existing units and lot size. Careful planning and consideration of sightline disruptions for residents are essential.

Junior ADUs (JADUs)

Unique housing options in existing single-family homes. These compact units, usually under 500 sq ft, maximize living space with flexibility and creativity. JADUs, unlike standard ADUs, can be created from garages or basements, seamlessly integrating into the main dwelling. They often share utilities and bathrooms, fostering a closer connection between occupants.

Property Designations

• Flood zones: Check if your property falls within a designated flood zone. Building in these areas might require specific flood mitigation measures or even be prohibited altogether.
• Geohazard zones: Be aware of potential geohazards like landslides, earthquakes, or sinkholes. Building in these zones might necessitate additional structural reinforcements or specific foundation designs.
• Historic designation: If your property is listed on the National Register of Historic Places or designated as a local historic landmark, stricter design guidelines and approvals might apply to your ADU. Preserve the historical character of the neighborhood while incorporating your ADU vision.
• Easements: These are legal rights granted to utilities or other entities to access specific portions of your property. Building an ADU cannot obstruct or interfere with existing easements. Identify and understand any easements on your property before proceeding.

Pre-Approved Duarte ADUs

Unfortunately, as of October 27, 2023, Duarte doesn’t have a program offering pre-approved ADU plans. Each proposed ADU goes through a full permit review process before receiving approval. While this might require more effort, it allows for greater flexibility in tailoring your ADU to your specific needs and property characteristics.

Start Your ADU Project Today!

Start your ADU project today with our expert team! We’ll guide you from concept to construction, handling everything from zoning to design choices. Call us at 877-979-3485, and let’s make your dream a reality!

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