ADU Alliance

ADU Living Unit In San Diego County: A Comprehensive Guide

ADU Alliance brings you an in-depth exploration of ADU living unit in San Diego County. From understanding the concept of ADUs to uncovering the potential benefits and cost factors, this article is your ultimate guide to maximizing the value of your property.

adu living unit in san diego county

Key Takeaways:

  • The versatility of ADU living unit in San Diego County.
  • Insights into ADU garage conversion costs.
  • A closer look at the meaning and advantages of ADUs.
  • Expert recommendations for navigating the ADU landscape.

What is ADU?

  • Accessory Dwelling Units (ADUs) have become a popular and flexible solution for homeowners in San Diego County. An ADU is a secondary housing unit on a single-family residential lot, either attached to the primary residence, detached in the backyard, or converted from existing space. The term “ADU” stands for Accessory Dwelling Unit, providing homeowners with additional living space, often with a separate entrance, kitchen, and bathroom.

Now, let’s delve into the diverse aspects of ADU living unit in San Diego County.

Exploring ADU Living Unit in San Diego County

Understanding the ADU Landscape

San Diego County’s real estate is witnessing a transformative trend with the rise of ADU living unit in San Diego Couonty. These units offer a myriad of possibilities, from accommodating family members to providing rental income. The growing popularity of ADUs can be attributed to their adaptability and cost-effectiveness.

Benefits of ADU Living Unit in San Diego County

  • Increased Property Value: Incorporating an ADU can significantly enhance the market value of your property.
  • Rental Income Potential: Renting out an ADU provides homeowners with a valuable income stream.
  • Flexible Living Arrangements: ADUs offer a flexible living space, suitable for various needs such as a home office or guest quarters.

ADU Garage Conversion Cost in San Diego County

  • One of the most intriguing aspects of ADUs is the garage conversion option. Transforming a garage into a living space is a practical solution, but understanding the associated costs is crucial.
Factors Influencing ADU Garage Conversion Cost
  • Size of the Garage: Larger garages may incur higher conversion costs.
  • Materials and Finishes: High-quality materials and finishes can impact the overall cost.
  • Permitting and Regulatory Fees: Compliance with local regulations may involve additional expenses.

Managing ADU Garage Conversion Costs

  • ADU Alliance specializes in optimizing garage conversion costs in San Diego County. Our experts navigate the permitting process efficiently, ensuring a seamless transformation within budget constraints.

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 for ADU living unit in San Diego county. 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 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 living unit in san diego county laws

Where Are ADU Living Unit in San Diego County Allowed?

  • 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 Living Unit 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 laws in San Diego County. 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.

expert adu living unit in san diego county


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 Permit Cost Breakdown

  • As part of a temporary county fee waiver program through January 2024, ADU laws in San Diego waive certain ADU plan check costs. However, you must still pay building permit fees, impact fees, and potentially utility connection and capacity charges.

Typical ADU permit costs include:


Plan Check Fees

  • Review of construction plans
  • $800 – $2,500
  • Waived through January 2024

Building Permit Fees

  • Approval to begin construction
  • $2,500 – $5,000+

Impact Fees

  • Offset community facility impacts
  • $2,000 – $15,000+

Utility Connection Fees

  • Water, electrical, sewer, etc
  • $2,000 – $15,000

Total Budget: $7,000–$40,000+, depending significantly on size and whether utilities require upgrades. You can use ADU cost calculators to estimate expenses. Get proposals from reputable builders to dial in accurate pricing.

attached adu living unit in san diego county

Crafting Your Unique ADU

ADU Alliance offers a range of services to cater to your specific needs:

  • ADU Architecture: Tailor your ADU’s design to match your property aesthetics.
  • ADU Construction: Efficient and reliable construction services for your ADU project.
  • ADU Remodeling: Enhance and customize your existing ADU with our remodeling expertise.

The ADU Living Unit Revolution

  • As San Diego County evolves, ADU living units play a pivotal role in shaping modern residential spaces. From innovative design concepts to sustainable construction practices, ADU Alliance is at the forefront of this revolution.


Unlock the potential of your property with ADU living unit in San Diego County. Whether you’re exploring the meaning of ADU or considering a garage conversion, ADU Alliance is your go-to expert for comprehensive guidance. Embrace the future of residential living with versatile and cost-effective ADUs, Contact us today (760) 456-8747.