A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in San Francisco, CA
An ADU (accessory dwelling unit – a small, separate living space on the same lot as your main house) is one of the smartest ways to add usable square footage in San Francisco, where land is scarce and waiting on new construction rarely makes sense. Our team at Lodgewick ADU San Francisco handles the whole picture: garage conversions, basement ADUs, and detached backyard units built to fit lots carved into hillsides and squeezed between Victorians. San Francisco’s older housing stock, strict seismic codes, and damp marine climate mean ADU work here looks nothing like it does in the East Bay or South Bay. Call (707) 760-0502 and we’ll explain what’s possible on your specific lot.
Why San Francisco Homes Are Different
Most San Francisco homes were built before the 1940s: Victorian and Edwardian single-family houses in Noe Valley and Bernal Heights, 1920s and 1930s apartment buildings in the Richmond and Sunset, all of them built long before anyone imagined earthquake retrofitting. That means when we open up a garage or basement for a conversion, we’re usually the first people seeing the foundation in 80 years. Seismic upgrades happen on almost every job here: floor plates bolted, shear walls added, sometimes a full foundation replacement before we even get to framing.
The climate shapes the interior work, too. Fog rolls through the Sunset and Richmond most summer afternoons, and winters bring steady rain off the Pacific. Moisture management is the thing people forget about until a year later when the drywall starts blooming. We overspec ventilation and use materials that tolerate humidity. Heating matters more than cooling; a small heat pump handles most San Francisco ADUs without issue.
Terrain is the third wildcard. In hillside neighborhoods like Diamond Heights, Glen Park, and Twin Peaks, a detached ADU might need piers drilled into the slope, or a demolition plan that takes a crane into a backyard with no street access. Even flat neighborhoods have surprises: in parts of the Sunset and Richmond built on old dunes, garage conversions can require raising the finished floor above floodplain elevation before permits get issued.
Our Main San Francisco Services
These are the three jobs San Francisco homeowners call us about most. Each has its own dedicated page with pricing, timelines, and San Francisco-specific detail.
Home Addition Contractor in San Francisco
A home addition in San Francisco means expanding outward or upward on a lot that’s usually already tight against its setbacks. We handle bump-outs over garages, rear additions that open onto the garden, and full second-story builds on single-story homes in the Outer Sunset and Excelsior. Planning review here is methodical and sometimes slow: expect geotechnical review on sloped lots, neighborhood notification requirements, and structural calcs tied to San Francisco’s seismic zone. The payoff is space that stays in the family as kids return from school or parents move in. Home Addition Contractor in San Francisco gives you the full breakdown.
Garage Conversion Contractor in San Francisco
Most garages in San Francisco are ground-floor spaces under occupied living space, built when cars were smaller and buildings were brick or unreinforced masonry. Converting one into a studio or one-bedroom ADU usually means digging down for ceiling height, waterproofing a floor that sits at or below grade, and opening walls for seismic reinforcement. In neighborhoods like the Inner Richmond or Mission, the old garage is often the only place to add a unit without touching the house’s existing footprint. Read the Garage Conversion Contractor in San Francisco page for the process and honest pricing.
ADU Builders in San Francisco
A detached backyard ADU is the best option when the garage or basement won’t cooperate: shallow lots, low ceilings, or homeowners who simply don’t want construction inside the existing house. In San Francisco, that often means building on a sloped rear yard, which brings retaining walls, drainage, and foundation piers into the picture early. We handle permitting, utilities, and design, and we work with prefab manufacturers like Boxabl and Plant Prefab when the site allows; some San Francisco backyards simply don’t allow crane access, and stick-built on piers is the only path through. The full ADU Builders in San Francisco page covers both paths in detail.
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.
The Kingswell Way
Every Lodgewick project runs on a simple set of rules we call The Kingswell Way: we put the price in writing before any work starts, we show up in the arrival window we give you, we leave the job site cleaner than we found it, and we put the guarantee in writing, not in a handshake. The 365-Day Done Right Promise means exactly what it says: if something on our work fails within 365 days, we come back and fix it at no charge. That promise is in writing on every project. When you call, a live person answers, 24/7, not a voicemail loop. Ask for Russ Delmar, who runs the San Francisco team, and he’ll make sure your project gets handled the same way.
Brands We Service in San Francisco
We work with several established ADU systems and material lines, including Boxabl and Plant Prefab for panelized buildings, plus Tuff Shed for storage-adjacent structures when a simple workspace solves the problem. James Hardie siding handles San Francisco’s damp, foggy conditions without warping. See our brands page for what each line offers.
Pricing for ADU Company in San Francisco, CA
| Service | Typical range in San Francisco |
|---|---|
| Home addition (bump-out, 200 – 400 sq ft) | $95,000 – $180,000 |
| Home addition (full second story) | $220,000 – $450,000 |
| Garage conversion (to studio ADU) | $120,000 – $240,000 |
| Garage conversion (to 1-bedroom ADU) | $140,000 – $280,000 |
| Basement conversion to ADU | $150,000 – $320,000 |
| Detached ADU (prefab, 400 – 600 sq ft) | $150,000 – $280,000 |
| Detached ADU (stick-built, 400 – 600 sq ft) | $180,000 – $350,000 |
| JADU (junior accessory dwelling unit, ~500 sq ft within existing home) | $80,000 – $150,000 |
| Seismic retrofit (bolt & shear wall, foundational work) | $15,000 – $40,000 |
| Foundation replacement (previous structure) | $25,000 – $60,000 |
| Kitchen remodel (within ADU or addition) | $40,000 – $95,000 |
| Bathroom remodel (within ADU or addition) | $25,000 – $60,000 |
In San Francisco, the two big price movers are seismic work you can’t see and site access your contractor can’t control. A lot on a downslope in Diamond Heights with a 40-foot retaining wall will cost more than a flat lot in the Sunset, no matter which builder you hire. Whatever the number, you get it in writing before work begins, and it does not change at the door.
Neighborhoods We Serve in San Francisco
Our team works all over San Francisco, from the fog belt to the bay side. Response time for site visits in the city is usually within 3 to 5 business days, depending on how many permitting consultations are already queued.
- Sunset District (Inner and Outer)
- Richmond District (Inner and Outer)
- Noe Valley
- Glen Park
- Bernal Heights
- Mission District
- Excelsior
- Diamond Heights
Service Area – Cities Near San Francisco
Our San Francisco Bay Area scheduling office coordinates crews for the city and nearby communities. We also serve Daly City, CA, Sausalito, CA, Emeryville, CA, and San Bruno, CA.
Serving San Francisco, CA - Our Local Coverage Area
We’re based in the San Francisco 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 Francisco
We schedule site visits across San Francisco within 3 to 5 business days in most cases. Dense neighborhoods like the Mission or Inner Richmond don’t slow us down; we coordinate from our San Francisco Bay Area office and dispatch crews locally. Call (707) 760-0502 and we’ll get you on the schedule for an estimate.
Yes. We prepare and submit the plans, structural calcs, and permit packages for San Francisco Planning and the Department of Building Inspection, and we manage revisions, inspections, and final sign-off. You don’t have to navigate the city’s planning process alone – that’s part of what we do.
In most cases, yes. Hillside lots in Diamond Heights, Glen Park, and Twin Peaks typically need pier or caisson foundations plus retaining wall work, which adds cost and timeline. We’ll tell you exactly what your slope requires before you commit to anything, in writing, with the price attached.
Want a written price for your ADU project in San Francisco? Call (707) 760-0502 to schedule a free estimate with Russ Delmar and the Lodgewick ADU San Francisco team. The price you get is the price you pay, and the 365-Day Done Right Promise is in writing before we start.
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 Francisco Customers Say
"The ADU came out beautiful and the permitting, which terrified me, was handled start to finish. They kept me updated every week so I was never wondering what was happening."
- Shauna Mills"Turned our detached garage into a little guest house. Clean crew, respectful of the neighbors, and no mystery charges at the end. Love how it turned out."
- Carmela Fontes"I was nervous about adding on but they walked me through every step and every cost before we started. No surprise change orders halfway through like I'd heard horror stories about."
- Eleanor Pratt
