A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Sausalito, CA
Sausalito is one of the most beautiful places in the Bay Area to build an accessory dwelling unit, but it’s also one of the most demanding. Hillside lots, narrow switchback streets, and a damp maritime climate change how ADUs get designed, permitted, and built here. We’re Lodgewick ADU San Francisco, and we specialize in home additions, garage conversions, and ADUs across Sausalito – with a written price before work starts and a 365-Day Done Right Promise in writing on every project. Call us at (707) 760-0502.
Why Sausalito Homes Are Different
Most Sausalito homes weren’t built for the kind of construction ADUs require. The housing stock leans heavily toward early-to-mid 20th century hillside homes, many on lots with little flat ground to spare. That means your ADU probably won’t be a simple backyard box. More often, it’s multi-story, tucked under the existing house, or cut into the slope itself. We regularly see projects where the foundation and retaining wall are the biggest line items, not the framing.
The damp bay air is another Sausalito-specific challenge. Cool air, fog, and salt moisture push into lower levels and unventilated corners. If waterproofing and ventilation aren’t done right at the start, you’ll be chasing mold and rust within a year or two. On steep streets like those in the Hurricane Gulch area, we also have to plan access carefully – narrow switchback roads mean coordinating material deliveries and sometimes working with neighbors on staging. None of this is impossible. It just means the contractor has to plan for it before the first shovel goes in the ground.
Our Main Sausalito Services
Most Sausalito homeowners call us for one of three things: adding living space onto the main house, converting an existing garage, or building a detached or attached ADU. Here’s what each involves locally.
Home Addition Contractor in Sausalito
On a Sausalito hillside, a home addition isn’t just an extension of the floor plan – it’s often a structural project. Sloped lots may require piers, retaining walls, or grade beams before framing can even begin. We size the foundation for the soil and the grade, and we plan drainage from the start so the new space stays dry through Sausalito’s damp winters. If you’re adding a bedroom, bath, or family room and want a real price in writing first, start with our Home Addition Contractor in Sausalito page.
Garage Conversion Contractor in Sausalito
Many Sausalito garages are older than the homes around them and sit either at street level or partially below grade. Converting one into living space usually means raising the floor assembly, improving drainage at the foundation edge, and adding proper insulation and ventilation against bay moisture. We handle the whole conversion – electrical, plumbing, drywall, flooring, and finish work – under one written price. For details on how a Sausalito garage conversion works, see our Garage Conversion Contractor in Sausalito page.
ADU Builders in Sausalito
Detached ADUs in Sausalito almost always contend with slope, setbacks, and limited staging room. Attached ADUs under an existing hillside home face moisture and ventilation concerns that flat-lot builds never see. We work with prefab manufacturers and traditional stick-framing depending on your lot, and we pull permits, schedule inspections, and manage the whole process to final sign-off. A written price and a written guarantee come before anything else. Read more on our ADU Builders in Sausalito page.
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 Sausalito
We work with established ADU brands and materials, including Plant Prefab, Tuff Shed, James Hardie, and Abodu. Choosing the right system depends on your lot access, foundation requirements, and how much of the build you want handled off-site. We’ll match the brand to your Sausalito lot and budget, not the other way around.
Pricing for ADU Company in Sausalito, CA
| Service | Typical range in Sausalito |
|---|---|
| Detached ADU (prefab, 400-600 sq ft) | $180,000 – $320,000 |
| Detached ADU (site-built, 400-600 sq ft) | $250,000 – $400,000 |
| Attached ADU under existing home | $200,000 – $350,000 |
| Garage conversion (single-car to studio) | $120,000 – $180,000 |
| Garage conversion (two-car to one-bedroom) | $150,000 – $220,000 |
| Home addition (ground-level, 200-400 sq ft) | $150,000 – $280,000 |
| Home addition (hillside, with retaining wall) | $220,000 – $400,000 |
| Foundation and retaining wall work (hillside) | $40,000 – $120,000 |
| Waterproofing and ventilation upgrades | $15,000 – $45,000 |
| Permit and design package | $8,000 – $25,000 |
Hillside foundations and retaining walls are the two biggest cost drivers in Sausalito, followed by waterproofing details the damp climate makes unavoidable. Whatever the final number, you’ll have it in writing before work starts – no price changes at the door.
Neighborhoods We Serve in Sausalito
We work across Sausalito, from the flats near Bridgeway up into the hills and gulches. Each area has its own access and terrain quirks, so we plan each project around the street itself, not just the lot.
- Hurricane Gulch
- Old Town / downtown Sausalito
- Nevada Street Valley
- Marinship
- New Town / north Sausalito
Service Area – Cities Near Sausalito
While this page focuses on Sausalito, our crews also serve nearby communities around the Bay. If you’re just outside Sausalito, you can also reach us in Corte Madera, CA, San Rafael, CA, San Francisco, CA, and Richmond, CA. Dispatch and scheduling are coordinated from the brand’s San Francisco Bay Area office, with crews serving Sausalito locally.
Serving Sausalito, CA - Our Local Coverage Area
We’re based in the Sausalito 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 Sausalito
Yes. Hillside development and geotechnical review are standard parts of most Sausalito ADU and addition permits, and we handle them as part of the project. Our permit and design package runs roughly $8,000 to $25,000 depending on scope, and we include it in your written price up front.
Most Sausalito ADUs run 6 to 14 months from design to final inspection, with hillside projects on the longer end and prefab ADUs often shorter. The permitting phase here can add 2 to 4 months. We give you a defined arrival window for every phase, in writing, before work begins.
No. The Kingswell Guarantee means the written price we give you before work begins is the price you pay, barring an agreed change order in writing. If something isn’t done right, we come back under the 365-Day Done Right Promise. Call (707) 760-0502 for a free estimate and a real number in writing.
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 Sausalito 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
