ADU Builder in San Diego County

Every year your home appreciates, but an empty yard corner or unused garage earns you nothing. An ADU changes that. It can bring in rental income, house a family member, or raise your appraisal and resale value. For many San Diego lots, it is the highest-return project you can build.

• Detached ADUs: a stand-alone backyard home
• Attached ADUs: a unit connected to the main house
• Garage conversions: turning an existing garage into a legal living unit (see our garage conversion page)
• Second-story additions: building up instead of out
• Permit and plan coordination for every project

Honest answer: it depends on the type, size, finish level, and site conditions (slope, soil, utilities, fire zone). Published 2026 San Diego figures:

Our own planning range for San Diego ADU construction is about $300–$500 per square foot. A detached 800 sq ft ADU often lands between $240,000 and $400,000.

City of San Diego permit records show the median construction value declared on 2026 single-ADU permits was $120,900. That number leaves out design, city fees, and utility work, so expect your all-in cost to be higher (sandiegoaducost.com, City permit data).

Want a ballpark for your lot? Use our free project calculator, then book a free on-site estimate. You will know the number before we start.

What moves the price:

• Conversion vs. new build: a conversion reuses an existing foundation and shell.
• Size and stories: two-story units need more structure and engineering.
• Utilities: a new sewer line, water meter, or electrical panel upgrade adds cost.
• Site: slopes, retaining walls, and fire-zone construction rules add cost.
• City fees: see the City of San Diego's Information Bulletin 400 for current fees.

Every ADU we build is fully permitted. We handle the plan set, the city submittal, the corrections, and the inspections. Rules differ by city: the City of San Diego, Carlsbad, Encinitas, Chula Vista, and unincorporated County areas each have their own process. Coastal lots (La Jolla, Del Mar, Encinitas, Coronado) can need extra coastal review. The City of San Diego's requirements are published in Information Bulletin 400.

Most contractors make you wait months while ADU plans crawl through permitting. We sequence your project so work starts now and never stops.

1. Phase 1, start now: remodel while you wait. Kitchen, bath, and interior remodels on the main house need few or no permits, so we can begin on day one.
2. Phase 2, plans clear: ADU and addition approved. Your ADU plans move through permitting in the background. When they clear, the crew moves straight into the build.
3. Phase 3, full buildout. We build the big pieces: the detached ADU, the second story, the addition. By then, half your project is already done.

Already have approved plans? We break ground right away.

1. Consult: We walk the property, talk through your goals and budget, and give you a straight read on the return potential.
2. Plan and permit: You get a detailed scope, a transparent estimate, and full permit and plan coordination before any construction starts.
3. Build: Owner-managed crews work to scheduled milestones, with steady communication so you always know where things stand.
4. Profit: A final walkthrough and a clean handoff. Then your new unit starts earning, whether you rent it, live in it, or sell the property.

One property, reimagined as two. At 3680–3682 Curlew St in San Diego, we added a second story to the main house and converted the garage into a separate unit. The owner now has two distinct, rentable addresses on a single lot, both move-in ready.

• 3682 Curlew St (main residence, second-story addition): chef's kitchen with a marble waterfall island, primary bath, dual shower with custom tile, and turf and hardscape backyard.
• 3680 Curlew St (garage conversion and remodel): open kitchen and living area, quartz waterfall island, marble shower, and a private rooftop deck with a hillside view.

See our work →

• Built for return. We design around the value you add (square footage, income, resale), not just the build.
• Licensed and accountable. CSLB license #768545. Fully insured and bonded. Owner-managed, so you have one point of responsibility from start to finish.
• Award-winning. Best of Houzz, 2016–2025.
• Honest scope and pricing. Clear estimates and disciplined change orders. You know the number before we start.
• See it before you build. Every new client gets one free 3D rendering from our in-house design software.
• Fast response. We reply within 24 hours.

We build across San Diego County. That includes La Jolla, Del Mar, Coronado, Point Loma, Pacific Beach, Carmel Valley, Encinitas, Carlsbad, Rancho Santa Fe, Poway, Escondido, La Mesa, El Cajon, Chula Vista, and nearby communities.