ADU Builders County of San Diego

The County of San Diego Accessory Dwelling Unit Guide

San Diego County, CA, USA

You’ve found the ultimate resource for building an accessory dwelling unit in the County of San Diego, California. Whether you’re a homeowner looking to maximize flexibility for family or an investor planning to add units, our comprehensive guide is here to assist you every step of the way. Read on for more on what you can build in San Diego County, rent rates, and to see completed & active ADU projects we are building in the County of San Diego. You can also access detailed ADU cost & floor plan information, plus check out homeowner stories.

San Diego County ADU QUICK FACTS

What you can build

Maximum size: 1200 sqft

Side/rear setbacks: 4 feet

Two story: Yes

Permitting timeline

Standard: 3-5 months

Coastal: TBD

Our ADU experience in San Diego County

Unincorporated areas are covered by the County of San Diego’s ADU rules and regulations. Additionally, some city properties are subject to County of San Diego ADU rules and regulations. This will depend on whether your city has incorporated the land on which your property is located. In some cities like Vista, San Marcos, Escondido, Oceanside, Encinitas, Del Mar, Chula Vista, El Cajon, Santee, and parts of San Diego, portions are regulated by County of San Diego and not the city. If you don’t know what jurisdiction applies to your property, we can look that up for you in early phases of our discussions.

The County requires in-person submission of plans, which adds some processing time and expense. Review times are moderate. Other agencies that are more proximate to the location of the residence may require input and approval (i.e., local fire agencies). The County has also put out standard floor plans, which some homeowners have found helpful as a starting place for their ADU designs.

San Diego County ADU Regulations & Permitting Requirements

Want to learn more about what kind of ADU you can build in San Diego County? Check out our in-depth resource guide San Diego County Regulations & Permitting Requirements outlining the ADU building code requirements. We also include what we have learned about how the city will interpret code based on actually designing & building in the city. You can also set up a consult if you want our advice on what you can build.
San Diego County ADU Regulations

How much does an ADU cost in San Diego County?

Glad you asked! Head on over to our ADU costs page for detailed info on all the different costs that go into building an ADU. You’ll see why the all-in cost can range from $300K to $450K+ depending on the size ADU you are building, as well as your property’s unique additional costs.

How much will an ADU rent for in San Diego County?

Below are median rental prices by zip code and bedroom count. Be sure to run comps for your specific area or check with a realtor.

91902County of San DiegoBonita190027253150
92003County of San DiegoBonsall160024503500
92028County of San DiegoFallbrook180029253625
92091County of San DiegoRancho Santa Fe250039005000
91977County of San DiegoSpring Valley207524503450

Source: Rentometer March 2024

ADU Builders County of San Diego

Full Accountability. ADU Expertise. Proven Results.

Our own team is responsible for delivering on our promises, from the first time you contact us to the time we hand you the keys to your new ADU home.

As experienced ADU builders, we will anticipate the pitfalls that less seasoned or less integrated teams will miss. And the volume of ADU jobs we handle means we have gained an incredible amount of expertise that we are excited to bring to your project.

We’re 100% focused on being the best ADU builders in San Diego County

Zip Codes: 91902, 91977, 91978, 92003, 92014, 92021, 92026, 92027, 92028, 92029, 92058, 92059, 92067, 92071, 92081, 92082, 92084, 92091, 92127

Neighborhoods: Bonita, Bonsall, Del Dios, Fairbanks Ranch, Fallbrook, Hidden Meadows, Lakeside, Mount Helix, Pala, Pala Mesa, Pauma Valley, Rancho Santa Fe, Rainbow, Spring Valley, Sweetwater, Twin Oaks, Valle De Oro, Valley Center, 4S Ranch