Huntington Beach ADU Guide

Accessory Dwelling Units (ADUs) are becoming increasingly popular in Huntington Beach. These versatile, separate living spaces offer a fantastic solution for families looking to accommodate aging parents or adult children. Beyond that, ADUs can significantly boost a property owner’s income, providing a stable rental stream. They’re also great for increasing property value and helping to ease the local housing crunch.

At ADU Builders CA, we’re committed to making your ADU construction journey as smooth as possible. Our in-depth Huntington Beach ADU guide is designed to walk you through every step, covering all the essential details about regulations, requirements, and the permit application process. We can’t wait to help you turn your ADU vision into reality.

Zoning Regulations in Huntington Beach

Building an ADU in Huntington Beach means navigating some specific zoning rules. Generally, ADUs are allowed in residential areas, though their size and where they can be placed will depend on your particular zone. Good news: the primary homeowner doesn’t need to live in the ADU, and you’re free to rent it out.

ADU Size Limitations

The size of an ADU you can build in Huntington Beach largely depends on your property’s lot size. Naturally, smaller lots will allow for smaller ADUs, while larger lots can accommodate bigger units. Keep in mind that single-family homes and multi-family residences have different size limits. Below, you’ll find a table detailing the maximum allowed floor area for ADUs, broken down by plot size and property type:

ADU Height Limitations

In Huntington Beach, your ADU can’t be taller than the main house. Single-story ADUs have a maximum height of 16 feet, while two-story units are capped at 24 feet. Be sure to choose your roof pitch and building materials with these height restrictions in mind.

Building Coverage

There’s a limit to how much of your property can be covered by buildings. The combined footprint of your main house and the ADU can’t take up more than 50% of your total lot size. This rule helps ensure there’s enough open space and landscaping. Parking areas, thankfully, don’t count towards this limit.

Location

Single-Family Properties:

If you have a single-family home, the rules for detached versus attached ADUs vary. Detached units need to be at least 6 feet away from the main house and can be located in either your backyard or side yard. Attached ADUs, however, must share the same roof structure as the main dwelling and need direct access.

Duplex and Multi-family Properties:

For duplexes and multi-family properties, ADUs typically require a separate entrance and must meet all safety regulations. It’s also worth noting that some specific zoning areas might have extra rules, so it’s always a good idea to check with the city before you start planning.

Exterior Details

The ADU’s exterior should blend seamlessly with your primary home. Pay close attention to paint colors, roof styles, and construction materials. When placing windows and doors, privacy for both dwellings should be a top priority. Using high-quality finishes for the exterior walls is also essential.

Parking

Every ADU needs a dedicated parking spot, whether it’s in a garage or an open space. This parking area should be easily accessible. In certain situations, this parking requirement might even be waived. Just make sure all your parking facilities meet city standards.

Setbacks and Buffer Zones

You’ll need to maintain specific setback distances around your ADU: 20 feet from the front, 10 feet from the rear, and 5 feet from the sides. These clearances are crucial for fire safety and privacy. Corner properties, by the way, have their own distinct regulations.

Minimum Lot Area (RF Zone)

While ADUs are generally allowed on smaller plots, residential areas do have established minimum lot sizes for construction. Different zones come with their own unique minimum size requirements, and you’ll need to get advance approval from the Municipal Corporation.

Here’s a table showing the minimum plot area required for ADU construction across various zones:

Utility Connections

ADUs need their own separate connections for electricity, water, and sewer. While these can be extended from your main house’s utility lines, having separate meters is a must. Remember, all connection work has to be done by licensed plumbers and electricians.

Before you start digging new utility lines, it’s smart to gather information on any existing underground pipes and cables. All connections must comply with building codes, and you’ll need prior authorization from utility companies. Don’t forget to plan for emergency repair access too.

Fire Safety

To keep your ADU safe from fire, smoke detectors and carbon monoxide alarms are absolute requirements. Make sure emergency exits are always clear, and have a fire extinguisher easily accessible. All electrical wiring and gas lines must be installed securely and to code.

Room Specifications

Sleeping Areas:

For bedrooms, you’ll need at least 120 square feet of space. Windows should bring in natural light and allow for good airflow, and they must be large enough for emergency escape.

Kitchen:

Your kitchen should be equipped with a sink, a stove, and space for a refrigerator. Countertops need to be at least 30 inches wide, and ample electrical outlets and proper ventilation are essential.

Bathroom:

Bathrooms must include a shower or tub, a toilet, and a wash basin, with a minimum size of 40 square feet. An exhaust fan is also a must-have.

Storage spaces:

Each room needs a closet or dedicated storage area. You’re required to have a minimum of 100 square feet of accessible storage space overall.

Short-term Rentals and Home Occupations Regulations

You can rent out your ADU for short periods in Huntington Beach, as long as each rental lasts at least 30 days. Operating a business out of your ADU is also permitted, but it shouldn’t disturb your neighbors and you’ll need to obtain a license.

Building Codes

All ADU construction must follow California building codes. This means using high-quality materials, ensuring all electrical and plumbing installations meet established standards, and undergoing regular inspections.

ADU Permit Huntington Beach Guidelines

Before you break ground on your Huntington Beach ADU, you’ll need to secure all the necessary permits. This involves submitting a detailed plan along with all relevant documentation. The permitting process usually takes about 2-3 months, and it’s a good idea to stay in touch with the Municipal Corporation for updates.

Here’s a table outlining common permit types for ADU projects, along with their estimated costs:

Property Requirements

The property you plan to build an ADU on should be in good condition. It’s crucial to conduct soil testing and understand the groundwater levels. If your property is in a flood- or earthquake-prone area, you’ll need to follow specialized construction standards. Also, keep in mind that you might need separate permission for any tree removal.

Parking

Every ADU requires a dedicated car parking space. This area needs to be paved and level, with a clear access route. If you’re converting a garage into an ADU, you’ll need to make sure substitute parking arrangements are in place.

Front Setbacks

Your ADU must be set back at least 20 feet from the street. For corner lots, setbacks are required from both adjacent roads. ADUs aren’t allowed in the front yard, and it’s a good idea to enhance the setback area with landscaping.

Side and Rear Setbacks

A minimum setback of 5 feet on the sides and 10 feet at the rear is compulsory. Remember to consider your neighbors’ privacy, and planting trees in these setback zones can be a nice touch. Ensuring clear access for emergency vehicles is also vital.

Open Space and Rear Yards

Even after building your ADU, you’ll need to retain sufficient open space on the property. Specifically, 30% of your backyard must remain clear. This area should be suitable for children’s play and gardening, and it’s important to install proper drainage systems.

Properties That Qualify

Nearly all residential properties in Huntington Beach are eligible for ADU construction, including single-family homes, duplexes, and multi-family structures. Your lot size must meet the minimum requirements, and the existing primary building needs to be deemed safe.

Special regulations apply to ADUs located in unique areas like historic districts or coastal zones. Design and construction in these locations demand extra attention. It’s absolutely crucial to verify all requirements before applying for a permit.

Development Standards

Single-family:

• Attached: For single-family properties, attached ADUs can’t be more than 50% the size of the primary house. They require a separate entrance and a soundproof wall separating the two dwellings.
• Detached: Detached ADUs on single-family lots need to be at least 6 feet away from the main house, with a height limit of 16 feet. They also need their own utility connections.

Duplex properties:

• Attached: For duplex properties, attached ADUs must be built to integrate seamlessly with the existing structure. Each unit needs separate utility meters, and specific fire prevention measures are required.
• Detached: Detached ADUs on duplex properties require sufficient open space. You’ll need to provide appropriate parking facilities, and adequate screening should be in place to ensure privacy.

Multifamily properties:

• Attached: For multi-family properties, the size of attached ADUs is restricted. The design must consider the characteristics of all existing units, and the use of common areas should be clearly defined.
• Detached: Separate ADUs on multi-family properties are subject to specific regulations. A robust security system is essential, and the consent of all current residents is mandatory.

Junior ADUs (JADUs)

A Junior ADU (JADU) is a compact unit, up to 500 square feet, built within the primary residence. It must include basic kitchen and bathroom amenities, and it can share a door with the main house. Good news for JADUs: they’re exempt from separate parking requirements.

Property Designations

• Flood Zones: If your property is in a Flood Zone, your ADU will need to be built to specific flood-resistant standards. This includes elevating the floor height above flood levels, using water-resistant materials, and planning for emergency evacuation routes.
• Geohazard Zones: In Geohazard Zones, taking special precautions is vital, especially for areas prone to earthquakes or landslides. Soil investigations and geotechnical reports are mandatory, and a robust foundation is absolutely essential. We highly recommend consulting a structural engineer.
• Historic Designation: For properties with a Historic Designation, the ADU’s design must perfectly match the original building’s architectural style. You’ll need approval from the Heritage Conservation Committee, and using traditional building materials to preserve the original look is paramount.
• Easements: You can’t build an ADU in areas designated as easements for public utilities. It’s crucial to ensure the safety of utility lines, respect neighboring property rights, and guarantee access for service providers.

Pre-Approved Huntington Beach ADUs

The Huntington Beach Municipal Corporation offers several pre-approved ADU designs, which can significantly speed up the permit application process. These designs come in various sizes and layouts and can be moderately customized to suit your preferences.

Even with pre-approved designs, the construction must follow standard procedures, including adhering to all inspection and quality control regulations. These designs are often popular because of their potential to save both cost and time. Our team is always here to help you select the most suitable option.