ADU Alliance

ADU Apartments In San Diego County: Embracing Versatility And Comfort

In this comprehensive guide, we delve into the world of Accessory Dwelling Units (ADUs) in San Diego County. Uncover the transformative potential of ADU apartments in San Diego County, explore the diverse services offered by ADU Alliance, and understand the intricate process of ADU construction and remodeling. Whether you’re considering a two-story carriage house or a modern backyard cottage, this article is your key to unlocking the full spectrum of possibilities. adu apartments in san diego county

Key Takeaways:

  • Versatility of ADUs: From 2-story carriage houses to detached granny flats, explore the myriad options.
  • Services by ADU Alliance: Learn about ADU construction, remodeling, design, permitting, and regulatory assistance.
  • Creative Living Spaces: Dive into the world of tiny homes, luxury flats, and customizable studio designs.
  • Backyard Transformations: Understand the process of adding a granny flat or constructing standalone ADU apartments in San Diego County.
  • Innovative Design: Explore modern and traditional styles, from Hamptons-inspired units to modular backyard cottages.

What is ADU?

  • ADU, meaning “Accessory Dwelling Unit,” refers to a secondary living space on a single-family property. Also known as backyard apartments, these units are designed for independent living and can take various forms, such as granny flats, guest houses, or converted garages. ADU apartments in San Diego County offer a flexible solution for homeowners to maximize space and provide additional housing options.

Recent California ADU Legislative Changes

In January 2023, California enacted AB 2221, AB 916, and SB 897 which contained over a dozen impactful changes for ADU laws in San Diego. Most notably:
  • Height Restriction Overrides: The new laws allow homeowners in certain areas to build 2-story detached ADUs subject to maximum height limits such as 18 or 25 feet, depending on location specifics. This enables the construction of ADUs with enough height for a second level.
  • Expedited Review: The state mandated a 60-day limit for local agencies to approve or deny ADU permit applications after submittal. This stringent deadline aims to accelerate project approvals.
  • Affordability Incentives: The ADU laws in San Diego County standardize an affordable housing density bonus that enables homeowners to build additional market-rate units if they designate some ADUs as income-restricted affordable housing.
San Diego County adopted guidelines to reflect these 2023 ADU apartments in San Diego County laws. The county’s updated ADU regulations include specific height allowances for 2-story units based on their proximity to transit and application review deadlines. adu apartments in san diego county permitting

Where Are ADUs Allowed in San Diego County?

  • You can only build an ADU on a residentially zoned property with an existing single-family home per county zoning regulations. Use this zoning lookup to verify your eligibility by entering your assessor’s parcel number (APN).
If your property qualifies, you may be able to have up to one detached ADU plus one junior ADU on the lot. A junior ADU (JADU) is a smaller dwelling (maximum 500 sq ft) created within the walls of the primary residence.
  • JADUs must include an efficient kitchen, separate entrance, and interior entry to the main home. The owner must reside on-site within either the JADU or primary dwelling.

ADU Laws in San Diego County: ADU Size Requirements

The maximum ADU sizes allowed depend on whether the unit is attached or detached:  
Square Footage of Existing single-family residence (SFD) Maximum Allowed Square Footage for Detached ADU Maximum Allowed Square Footage for Attached ADU (up to 50% of SFD)
Studio or 1 Bedroom ADU 2 Bedrooms  or more  ADU
500 sq. ft. 1,200 sq. ft. 850 sq. ft. 1,000 sq. ft.
1,000 sq. ft. 1,200 sq. ft. 850 sq. ft. 1,000 sq. ft.
1,800 sq. ft. 1,200 sq. ft. 900 sq. ft. 1,000 sq. ft.
2,000 sq. ft. 1,200 sq. ft. 1,000 sq. ft. 1,000 sq. ft.
2,200 sq. ft. 1,200 sq. ft. 1,100 sq. ft. 1,100 sq. ft.
3,000 sq. ft. 1,200 sq. ft. 1,200 sq. ft. 1,200 sq. ft.
4,500 sq. ft. 1,200 sq. ft. 1,200 sq. ft. 1,200 sq. ft.
There are no explicit limits on the number of bedrooms in a detached ADU.

Building Permit Requirements

Yes, you need to obtain a building permit before any kind of ADU construction, as per ADU apartments in San Diego County laws. This crucial process verifies your unit meets important health, safety, zoning, and building code regulations. The County PDS department reviews all ADU permit applications. They ensure your project adheres to regulations around:
  • Maximum size
  • Height restrictions
  • Setback minimums (distance from property lines)
  • Utility requirements
  • Parking rules
PDS also enforces the state’s 60-day application review limit. At a minimum, detached ADUs must provide:
Necessary Amenities
  • Complete kitchen
  • Bathroom (toilet, sink, shower)
  • Sleeping area(s)
  • Separate exterior entrance
Potential Other Requirements
  • Fire sprinklers
  • Parking space(s)
  • New utility meters and connections
Attached ADUs typically have lower amenity thresholds since they can share walls and systems with the main dwelling.

Utility Service Requirements

You will likely need independent utility infrastructure for a detached ADU, including:
  • Separate water line with a meter
  • Independent electrical panel and meter
  • Dedicated gas line, if applicable
  • Individual sewer/septic access
For attached ADUs, you can sometimes share utility connections with the primary dwelling or sub-meter of the ADU usage. Utility connection costs often reach $5,000+ for detached ADUs but may be far less for attached units. Verify requirements and costs upfront with local utility companies. adu apartments in san diego county construction

Backyard ADU Apartments in San Diego County – Unlocking Possibilities

  • As the demand for versatile living spaces continues to rise, ADU apartments in San Diego County emerge as a groundbreaking solution. At ADU Alliance, we specialize in transforming properties, offering a range of services that cater to every aspect of ADU construction, remodeling, and design.

Exploring ADU Apartments in San Diego County

  • Carriage House Apartments: Explore the charm of 2-story carriage houses and small carriage house designs, blending elegance with practicality.
  • Granny Flats for Every Need: From 1-bedroom granny flats to spacious 3-bedroom options, discover the perfect self-contained living space for your property.
  • Modern Tiny Homes: Dive into the trend of tiny homes and discover how ADU Alliance turns compact spaces into functional, stylish living areas.

Services by ADU Alliance

Our expertise extends across various facets of ADU development:
  • ADU Construction: Transform your property with our expert construction services.
  • ADU Remodeling: Revamp existing structures into modern living spaces, including detached granny flats and studio designs.
  • ADU Designing: Tailor the design of your ADU apartments in San Diego County to match your lifestyle and preferences.
  • ADUPermitting: Navigate the permitting process seamlessly with our assistance.
  • ADU Regulatory Assistance: Stay informed and compliant with ADU regulations and guidelines.
adu apartments in san diego county contractors

Backyard ADU Apartments in San Diego County: Construction Process

  • Conceptualization: Explore design options and choose the style that suits your property.
  • Permitting: Understand the necessary permits and navigate the regulatory landscape with our guidance.
  • Construction: Watch your backyard transform as our experts bring your ADU apartments in San Diego County to life.
  • Final Touches: Add personal touches and choose interior elements that reflect your style.

Backyard ADU and Additional Living Spaces

In addition to ADUs, our expertise extends to creating:

Building a Future with ADU Alliance

  • At ADU Alliance, we don’t just build ADUs; we create possibilities. Our commitment to quality, innovation, and customer satisfaction sets us apart as the premier choice for ADU construction and design in San Diego County.


Embrace the transformative power of ADU apartments in San Diego County with ADU Alliance. From innovative designs to expert construction, we are your partners in building a future of versatile and comfortable living spaces. As you embark on this journey with ADU Alliance, envision a home that not only meets your current needs but evolves with you. Contact us at (760) 456-8747 to explore the endless possibilities of ADU living in San Diego County.