ADU Builders in San Diego, CA
Looking for an ADU builder in San Diego? ADUs, garage conversions, and backyard cottages can add living space, rental income, or room for family. This page lists local ADU contractors and summarizes basic cost and permit considerations for San Diego homeowners.
San Diego is arguably California's most permissive big-city ADU market, with a bonus ADU program that can allow multiple units on a single lot. Homeowners build ADUs for rentals, family housing, and long-term property value.
Featured ADU contractors in San Diego
Serves San Diego County, from coastal areas like La Jolla and Carlsbad to inland communities like Poway and El Cajon
Design-build, Detached ADUs, Attached ADUs, Garage conversions
Serves San Diego County, including the City of San Diego, Chula Vista, Oceanside, Escondido, Carlsbad, and El Cajon
Construction management, Design & permitting, Pre-approved plans
Serves San Diego County, including Vista, Oceanside, Escondido, Chula Vista, and Valley Center
Modular ADUs, Custom ADUs, Garage conversions
Serves San Diego County, covering 22+ communities including La Jolla, Del Mar, Coronado, Chula Vista, Escondido, and Poway
Design-build, Detached ADUs, Garage conversions, Junior ADUs, Fixed-price contracts
Serves San Diego County
Standalone ADUs, Above-garage ADUs, Garage conversions
Serves San Diego County, including Poway, Rancho Bernardo, Scripps Ranch, Carmel Valley, La Jolla, and Encinitas
Design-build, Detached ADUs, Garage conversions, Basement conversions, Junior ADUs
Serves San Diego, California
Design-build, Detached ADUs, Junior ADUs, 3D design
Serves San Diego County, from Oceanside to San Ysidro and inland to Alpine
Design-build, Pre-designed floor plans, Feasibility studies, Financing assistance
Serves San Diego, California
Custom design, Detached ADUs, Garage conversions, Solar installation
Serves San Diego County
Design-build, Garage conversions, Custom design
Serves San Diego and surrounding areas including Chula Vista, El Cajon, La Mesa, Poway, and Santee
Garage conversions, Detached ADUs, Attached ADUs
Serves Greater San Diego County, including coastal cities like Oceanside and Encinitas and inland communities like Poway and El Cajon
Design-build, Detached ADUs, Fixed-price contracts
Serves San Diego County
Detached ADUs, Attached ADUs, Garage conversions, Junior ADUs, Aging-in-place remodeling
Serves North, central, and east San Diego County, including Chula Vista, El Cajon, Poway, and Lemon Grove
Detached ADUs, Attached ADUs, Junior ADUs, Foundation & framing
Serves San Diego and surrounding Southern California areas
Detached ADUs, Garage conversions, Basement conversions, In-law suites
ADU costs in San Diego
General estimated ranges:
- Garage conversion: $100,000–$185,000
- Detached ADU: $180,000–$400,000
- Design/permitting: varies by project
Estimates only — actual costs vary by site, size, and finishes. See the full San Diego ADU cost guide.
Common ADU project types
- Detached ADU
- Garage conversion — see San Diego garage conversion contractors
- Junior ADU
- Basement conversion
- Prefab ADU
ADU permits in San Diego
San Diego goes beyond state law with its ADU Bonus Program (extra units in exchange for deed-restricted affordable units in transit areas), waived fees for smaller units, and pre-approved standard plans. Most residential lots qualify for at least one ADU plus a JADU.
State law's 60-day review applies; San Diego's standard plans and dedicated ADU review can be faster. Typical custom projects run 2–4 months from design start to permit issuance.
Questions to ask an ADU builder
- Have you completed ADUs in this city?
- Can you help with design and permits?
- Do you handle utility connections?
- Can you show recent examples?
- Are you licensed and insured?
FAQ
How much does an ADU cost in San Diego?
Most detached ADUs in San Diego land in the $180,000–$400,000 range all-in, depending on size, finishes, and site conditions. Garage conversions typically run $100,000–$185,000. These are editorial estimates — get multiple quotes for your specific property.
Do I need a permit to build an ADU in San Diego?
Yes. Every ADU and garage conversion in San Diego requires building permits. The good news: California law requires ministerial (no public hearing) approval for code-compliant ADUs. State law's 60-day review applies; San Diego's standard plans and dedicated ADU review can be faster. Typical custom projects run 2–4 months from design start to permit issuance.
How long does it take to build an ADU in San Diego?
Plan for 3–6 months of design and permitting, then 4–8 months of construction for a detached ADU. Garage conversions are usually faster — often 3–5 months of construction once permits are issued.
Can I rent out my ADU in San Diego?
Yes — long-term rentals (30+ days) of ADUs are allowed statewide in California. Short-term rental rules vary by city, so check San Diego's short-term rental ordinance before planning Airbnb-style use.
Does an ADU add value to my home in San Diego?
Generally yes. Appraisals vary, but a permitted ADU adds livable square footage and rental income potential, which supports resale value. Note that ADUs also increase your property tax assessment on the new construction value.
What's the difference between an ADU and a JADU?
A Junior ADU (JADU) is a unit of up to 500 sq ft created within the existing home, with an efficiency kitchen and shared or separate bath. A standard ADU is a full independent dwelling — attached, detached, or converted from a garage. Many San Diego lots qualify for one of each.
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