A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in San Diego, CA
Fielding ADU Builders builds accessory dwelling units, garage conversions, and room additions across San Diego, CA. The work here follows a rhythm set by the city itself: post-war ranch homes on generous lots in Clairemont and Allied Gardens, tight alley lots near the coast, and fire-conscious construction in the eastern canyons. San Diego’s mild climate means we pour slabs and frame walls in every month of the year, which keeps schedules predictable in ways other markets can’t match. Call (858) 264-3027 to talk through your lot and your budget.
Why San Diego Homes Are Different
San Diego’s single-family housing stock tilts heavily toward homes built between the late 1940s and the 1970s. In neighborhoods like Clairemont, Allied Gardens, and San Carlos, that means single-story ranch and minimal traditional homes on lots with real backyard space and, just as often, no HOA to fight. The raised foundations common to these older San Diego homes can simplify utility connections for a detached ADU, though tying a new concrete slab to an existing raised foundation takes planning. Near the coast, the picture changes entirely. Ocean Beach and Pacific Beach lots run small and dense, with coastal height limits pushing many ADUs into what locals call alley flats, second units that face the rear alley and often carry rooftop decks to catch the breeze.
Climate shapes the material choices here. San Diego’s dry summers and wildfire risk zones in the eastern and northern parts of the city mean some projects need fire-resistant siding and defensible space built into the plan. The city’s low rainfall also makes stormwater management a real permitting conversation, permeable surfaces and drainage get reviewed closely. And because San Diego rarely freezes, we don’t overbuild for cold the way a contractor in the Midwest would. Insulation and HVAC loads stay leaner, which keeps costs where they should be.
Our Main San Diego Services
Three services make up most of what we do in San Diego, each with its own dedicated page that covers pricing, permits, and the local conditions in depth.
Room Addition Contractor in San Diego
Room additions in San Diego usually mean expanding a post-war ranch sideways or adding a second story over an existing footprint. The raised foundations on older Clairemont and San Carlos homes change how we tie new framing to old, and coastal height limits in Pacific Beach can force a design decision early. We write the full price before any work starts, and every addition gets the one-year Garrison Standard guarantee. For the full breakdown, see our Room Addition Contractor in San Diego page.
Garage Conversion Contractor in San Diego
San Diego garages from the 1950s and 60s often sit on their own slab, detached from the house, which actually makes a conversion cleaner than on newer attached garages. The tradeoff is that many older San Diego garages were never designed for living load, so we spend real time on foundation inspection and seismic anchoring before framing interior walls. Alley-facing garages in beach neighborhoods convert especially well into rentable units. Details and local pricing live on the Garage Conversion Contractor in San Diego page.
ADU Builders in San Diego
San Diego’s ADU market splits two ways. Inland lots in Allied Gardens and San Carlos favor detached units with room to spare. Coastal lots in Ocean Beach and Pacific Beach favor compact two-story or alley-facing designs that work within height limits and tight setbacks. We build conventional stick-frame ADUs with James Hardie siding and also work with prefab platforms like Abodu and Plant Prefab when the lot and budget point that direction. The ADU Builders in San Diego page covers it all.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in San Diego
We work with the prefab and modular platforms San Diego homeowners are already researching, including Abodu and Plant Prefab, plus conventional builds using James Hardie siding. Tuff Shed-style structures work for some simple detached units. See our brands for the full list and what each method costs per square foot here.
Pricing for ADU Company in San Diego, CA
| Service | Typical range in San Diego |
|---|---|
| Standard detached ADU (400 – 600 sq ft) | $180,000 – $280,000 |
| Standard detached ADU (600 – 800 sq ft) | $240,000 – $350,000 |
| Standard detached ADU (800 – 1,000 sq ft) | $280,000 – $400,000 |
| Premium detached ADU (1,000+ sq ft) | $350,000 – $500,000+ |
| Garage conversion ADU (standard finish) | $90,000 – $150,000 |
| Garage conversion ADU (premium finish) | $130,000 – $200,000 |
| Attached ADU (junior ADU or addition) | $120,000 – $220,000 |
| Prefab/modular ADU (turnkey, on site) | $160,000 – $300,000 |
| Room addition (300 – 500 sq ft) | $90,000 – $180,000 |
| Room addition (500 – 800 sq ft) | $150,000 – $280,000 |
| Room addition (800+ sq ft, or second story) | $240,000 – $400,000+ |
Coastal lots and anything requiring a setback variance will push the low end of those ranges up in San Diego. Wherever your project lands, the number we put in writing before work starts is the number on the final invoice. No change orders, no door-price surprises.
Neighborhoods We Serve in San Diego
Our crews cover the full city, from the beach communities up through the inland mesas and east into the canyons. Scheduling runs tightest in the coastal neighborhoods where alley access and shared driveways slow material delivery, so plan a little extra lead time if you are in one of those pockets. Most San Diego estimates get scheduled within a few days of the call.
- Clairemont
- Allied Gardens
- San Carlos
- Ocean Beach
- Pacific Beach
Service Area – Cities Near San Diego
Fielding ADU Builders serves San Diego and the surrounding communities, with scheduling coordinated from our San Diego office. Homeowners in Coronado, CA, National City, CA, Lemon Grove, CA, and Bonita, CA get the same written-price-first policy and one-year guarantee as our San Diego projects.
Serving San Diego, CA - Our Local Coverage Area
We’re based in the San Diego area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Company in San Diego
Most San Diego homeowners get an estimate within a week of calling, and permits in the city typically take four to eight weeks depending on the scope. Prefab ADU projects can start sooner because the unit is built off-site while San Diego permits clear. Call (858) 264-3027 and we will give you a straight timeline for your specific lot.
Many San Diego homes, especially mid-century neighborhoods like Clairemont and San Carlos, have no HOA at all. Where an HOA does exist, state law limits what it can restrict on ADUs, but the HOA can still weigh in on exterior finishes and landscaping during design review. We check this before you commit to a plan.
Yes. San Diego requires building permits for garage conversions, ADUs, and room additions, and the city reviews plans for structural, plumbing, electrical, and stormwater compliance. Fire-resistant materials matter in wildfire risk zones east of the 15. We pull permits on every project, no exceptions, and the work gets inspected before we call it done.
Call (858) 264-3027 to schedule a free estimate. A live person answers, 24 hours a day, and you will get a written price before any work starts.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What San Diego Customers Say
"Insulation, drywall, and finishes were all well done. Feels like part of the house."
- Pete O."Good addition. Electrical inspection delayed a week, which was the county, but the build is great."
- Eva K."Honest feedback on what the lot could fit. Told me up front what would fit on the lot and what the setbacks would allow."
- Rita C.
