ADU Contractors in San Diego
Complete design-build solutions for Accessory Dwelling Units. From architectural drawings to finished construction — one licensed contractor handles it all.
Building an Accessory Dwelling Unit (ADU) is one of the smartest investments a San Diego homeowner can make. Whether you want a rental unit for passive income, an in-law suite for family, or a home office detached from the main house, Subworkit Contracting handles the entire process — design, engineering, permits, and construction — as your single-source ADU contractor.
California's ADU-friendly legislation has made it easier and more profitable than ever to add a secondary dwelling to your San Diego property. ADUs in San Diego County command $1,800–$3,500/month in rental income, generating a typical payback period of just 5–8 years on most builds. The City of San Diego, Chula Vista, El Cajon, La Mesa, Escondido, and surrounding jurisdictions have all streamlined their ADU approval processes — and our team navigates these regulations daily. Senate Bill 9 (SB 9), effective January 2022, now allows most single-family lots to split their lot and add an ADU and JADU, potentially creating up to 4 units on what was a single-family parcel. We understand the zoning requirements, setback rules, parking exemptions, and utility connection standards for each San Diego city we serve.
Our ADU construction process begins with a thorough site evaluation and feasibility assessment. We'll determine what type of ADU — detached, attached, garage conversion, or Junior ADU (JADU) — works best for your property and goals. Our in-house architectural team then creates custom plans that maximize your space while meeting all Title 24 energy requirements, structural engineering standards, and local building codes.
Cost transparency is a cornerstone of our ADU services. We provide detailed, itemized estimates that break down every phase of the project. Garage conversion ADUs are typically the most affordable path — starting around $75,000–$110,000 for a fully permitted 1-bed/1-bath unit. Junior ADUs (JADUs) created within existing home space can come in at $50,000–$80,000. Detached ADUs range from $150,000–$280,000+ depending on size and finishes — and at San Diego's current rental rates, a $180,000 ADU generating $2,800/month pays for itself in about 5.4 years. There are no surprise change orders. Most ADU projects take 4–6 months after permit approval, and we keep you informed with regular progress updates throughout the build.
What We Offer
Custom ADU Design
Architectural drawings tailored to your property and lifestyle. Studio, 1-bedroom, and 2-bedroom layouts with modern finishes and efficient floor plans.
Engineering & Title 24
Structural engineering, energy calculations, Title 24 compliance reports, and soils reports — all coordinated by our team.
Permit Filing & Approvals
Complete permit application handling, plan check responses, city corrections, and inspection scheduling. We manage the bureaucracy so you don't have to.
Ground-Up Construction
Foundation, framing, roofing, plumbing, electrical, HVAC, insulation, drywall, flooring, and finish work — all performed by our licensed crews.
Garage Conversions
Convert your existing garage into a fully permitted ADU with proper insulation, utility connections, windows, and finishes.
Junior ADU (JADU)
Create a JADU of up to 500 sq ft within your existing home. A cost-effective way to add rental income or family living space.
Why Choose Subworkit as Your ADU Contractor?
One-Stop Shop — Design, engineering, permits, and construction all handled by our team
Licensed General Contractor — CA License #945572 with full insurance coverage
Local ADU Expertise — Deep knowledge of city-specific zoning rules and approval processes
Transparent Pricing — Detailed, itemized estimates with no hidden costs or surprise change orders
Quality Construction — Premium materials, skilled crews, and proper inspections at every phase
Proven Track Record — Successful ADU completions across San Diego County
Our ADU Construction Process
Free Consultation
We evaluate your property, discuss your goals (rental income, family housing, etc.), and determine the best ADU type for your lot.
Design & Engineering
Our architects create custom plans and engineers prepare structural calculations, Title 24, and any required reports.
Permits & Approvals
We submit plans to the city, handle plan check comments and corrections, and schedule all required inspections.
Construction
Our licensed crews build your ADU from foundation to finish — typically 4–6 months after permit approval.
Project Pricing
ADU construction timelines and budgets vary by project size, materials, and site conditions. We offer detailed, transparent estimates at no cost during our free consultation.
Contact us for a detailed quote tailored to your specific project.
Frequently Asked Questions
How much does it cost to build an ADU in San Diego?
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ADU costs depend on size, site conditions, materials, and finishes. We provide detailed, itemized estimates during our free consultation.
How long does it take to build an ADU?
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From design to completion, a typical ADU takes 8–12 months. This includes 2–4 months for design, engineering, and permits, followed by 4–6 months of construction. Timelines vary by city and project complexity.
Do I need a permit to build an ADU?
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Yes, all ADUs in California require building permits. The good news is that state laws have streamlined the process and limited cities' ability to block ADU construction. We handle all permit applications and approvals.
Can I rent out my ADU?
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Yes. California law allows homeowners to rent ADUs at market rates, making it an excellent investment for additional income.
What's the difference between an ADU and a JADU in San Diego?
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An ADU (Accessory Dwelling Unit) is a fully self-contained dwelling — detached or attached — up to 1,200 sq ft with its own kitchen, bathroom, and entrance. A Junior ADU (JADU) is carved from existing home space (garage, bedroom, etc.), limited to 500 sq ft, and must have its own exterior entrance and a kitchenette. In San Diego, both can be rented at market rates. JADUs are the most cost-effective option ($50,000–$80,000), while detached ADUs range from $150,000–$280,000+ depending on size and finishes.
How much rental income can I earn from an ADU in San Diego?
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San Diego ADU rental income ranges from $1,500–$2,200/month for a studio or JADU, and $2,200–$3,500/month for a 1–2 bedroom ADU, depending on location and amenities. Premium zip codes like La Jolla (92037), Coronado (92118), and Encinitas (92024) can exceed these ranges. Most clients achieve full payback within 5–8 years through rent collection alone — after which the ADU generates pure passive income.
What is SB 9 and can it allow more than one ADU on my lot?
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Senate Bill 9 (SB 9), effective January 1, 2022, allows most California single-family homeowners to split their lot into two parcels and/or add additional dwelling units. On eligible lots, this can enable an ADU plus a JADU on each resulting parcel — potentially 4 units on a formerly single-family property. SB 9 eligibility depends on zoning, parcel size, location (urban infill zones), and historic overlay restrictions. Our team evaluates your lot's SB 9 eligibility as part of your free ADU consultation.
Real Project Spotlight
Detached 400 sq ft ADU in El Cajon — Full Build from Permits to Keys
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Let's discuss your property, your goals, and your budget. Contact us today for a no-obligation consultation with experienced ADU contractors in San Diego.
Where We Serve
We build ADUs throughout San Diego County including La Mesa, El Cajon, National City, Chula Vista, La Jolla, Escondido, Oceanside, Carlsbad, Poway, and all surrounding communities. Our team is familiar with ADU regulations in each San Diego jurisdiction.
What Our Clients Say
"This is a very nice company that offered the services I needed. If you are in need of a company that does a clean and professional job, then I highly recommend Bernard and his team!"
— Happy Customer
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