Looking for accessory dwelling unit services in San Diego, CA? Call AccessoryDwellingUnit Services for a contact a provider — no obligation. Licensed adu builders serve San Diego and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.

About this service

These services cover the end-to-end process of adding a secondary home to your property. This includes initial zoning checks, architectural design, permit filing, and final construction. You need these services when you want to create a separate living space for family, guests, or as a rental unit, but don’t want to manage the complex legal and structural requirements on your own.

Frequently asked in San Diego

What are the disadvantages of ADUs?

How much does an ADU cost in California?

What are the rules for ADUs in California?

California has state laws that strongly support ADU construction, but local cities like San Diego still have specific regulations. These often cover setbacks, lot coverage, and parking requirements. Working with local experts ensures compliance. They will guide you through San Diego's specific requirements.

Is ADU allowed in my neighborhood?

Generally, ADUs are allowed in most residential zones across California, but specific neighborhood design guidelines or restrictions can exist. It's always best to verify. A quick call can get you advice specific to your San Diego location and its zoning.

What are the rules for ADU in California?

California has state-level laws encouraging ADUs, but local jurisdictions still set specific requirements. These can include setback rules, lot coverage limits, and parking requirements. Understanding these nuances is key. If you're considering an ADU in a California city, getting local advice is essential.

California has had various grant programs designed to offset the cost of building ADUs for homeowners. These programs often have specific eligibility criteria, such as income limits. Program availability and details can change over time. A local ADU service can help you explore current funding opportunities.

Also serving nearby: El Cajon · Chula Vista · San Marcos · Escondido · Carlsbad

All cities in California →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

1,388,320residents

4,257per sq mile

8ZIP codes served

Serving all of San Diego — population 1,388,320; about 4,257 residents per square mile across 326.1 sq mi. ZIP codes covered include 92101, 92102, 92103, 92104, 92105, 92106, 92107, 92108.

Neighborhoods served in San Diego: La Jolla, North Park, Hillcrest, Pacific Beach, Coronado, Mission Bay — and every surrounding area.