Marin County · Licensed Class B Builder
Custom Sauna Builder in Marin County.
We design, hand-build and maintain saunas, hot tubs, and cold plunges for Marin County. We are experienced in all kinds of products and are considered experts – which means you can trust us with your project!
- Custom-designed and hand-built to fit your space
- Premium untreated woods — western red cedar, hemlock, Nordic spruce
- Proper Finnish löyly engineering, not a hot box
- Permits handled end to end across all of Marin
Call now: 415-578-9210
About Our Work
Heat, water, and wood — done the way it should be.
Marin Sauna builds custom saunas, western red cedar hot tubs, and chiller-equipped cold plunges for homeowners across Marin County. Every project starts with a design conversation and a detailed plan, so you know exactly how the build will sit against your hillside, redwoods, or fog-line before anything is framed. We work only in premium untreated woods and engineer each sauna around real Finnish principles — rock mass, vent placement, and humidity tuned so the löyly feels soft and even. As a licensed Class B general contractor, we handle the permits, the finish carpentry, and the details most builders leave to chance. The result is a space built to last decades, not seasons.
Our Services
Custom saunas, cedar hot tubs, and cold plunges — designed and built start to finish.
Service · Marin
Custom Sauna Design & Installation
Full custom sauna design and licensed installation across Marin County — indoor conversions, backyard cabins, and commercial wellness builds, from first design to finished löyly.
- Licensed California Class B General Building Contractor, insured & bonded
- Detailed design and sign-off before any framing begins
- Premium woods: western red cedar, hemlock, Nordic spruce, thermo-aspen & abachi
- True Finnish löyly engineering — rock mass, vent placement & humidity dialed in
- Authorized installer for major heater & sauna kit brands
- In-house finish carpentry for benches, lighting, glass & trim
- Indoor, outdoor, rooftop & commercial builds across Marin County
Service · Marin
Sauna Kit Assembly & Build
Professional assembly and finishing of pre-fab sauna kits across Marin County — foundation, spec-correct build, heater wiring, and venting handled by a licensed builder.
- Licensed California Class B General Building Contractor, insured and bonded
- Authorized installer for major heater and kit brands
- Trained on Finnish and North American sauna standards
- We assemble nearly every major domestic, designer, and imported kit
- Spec-correct builds that keep your manufacturer warranty intact
- Foundation, electrical, venting, and finish handled under one roof
- Most kits completed in three to seven days, tested hot before we leave
Service · Marin
Sauna Maintenance & Repair
Annual care, heater repair, stone and wood restoration, and full bench rebuilds for saunas of any brand across Marin County — most calls finished in one visit.
- Any brand serviced — we didn't have to build it
- Most calls completed in a single visit
- Licensed Class B General Building Contractor, insured & bonded
- Trained on Finnish & North American sauna standards
- Materials and finishes matched to your existing build
- Annual maintenance plan available
- Serving San Rafael, Mill Valley, Tiburon, Sausalito & all of Marin County
Service · Marin
Cedar Hot Tub Install
Hand-built western red cedar hot tubs — electric or wood-fired, indoor or out — built to weather Marin and to pair beautifully with a sauna.
- Clear western red cedar, hand-cut and fitted
- Electric or wood-fired heat, indoor or outdoor
- Insulated, watertight wood — never plastic
- Pairs with sauna and cold plunge builds
- Engineered for decks, grades, and hillsides
- Permits, electrical, and plumbing handled
- Licensed Class B contractor, insured and bonded
Service · Marin
Cold Plunge Installation
Custom cold plunge design and installation across Marin County — insulated cedar, fiberglass, or stainless plunges with proper chillers, sanitation, and quiet filtration.
- Insulated cedar, fiberglass, and stainless trough plunges
- Properly sized 1–3 hp chillers for a steady 39–55°F
- Ozone & UV sanitation for clean water without heavy chemistry
- Quiet inline filtration suitable for living spaces
- Indoor, outdoor deck or pad, and rooftop installations
- Pairs with a sauna for full Nordic contrast therapy
- Licensed California Class B General Building Contractor, insured & bonded
Recent Builds
A few recent Marin County saunas.
A look at custom builds we have designed and crafted for homeowners across the county.
Ash-lined indoor retreat
A San Anselmo primary bath converted into a warm, low-glare sauna with pale ash benches and backrests, tuned for soft humidity and a quiet, even heat off the rocks.
Cedar barrel by the garden gate
A western red cedar barrel sauna set into a Fairfax garden, with a hand-built clear-grain door and bronze hardware chosen to weather gracefully under the redwoods.
Backyard sauna and outdoor shower
A Larkspur backyard wellness corner pairing a custom cedar sauna with an open-air shower, sited to catch afternoon light and rinse off before a cold plunge.
Eight-person hillside cabin
A generous cedar sauna built into a Novato hillside for a family that hosts, with tiered benches, a large rock mass, and venting engineered for a full house of bathers.
Warm-toned interior build
A Corte Madera basement transformed into a richly grained interior sauna, with hemlock walls, a backlit bench line, and a heater set for proper Finnish löyly.
Barrel interior, clear-grain cedar
The inside of a Mill Valley barrel sauna, finished in tight clear-grain western red cedar with curved benches shaped for comfort and airflow that draws clean and even.
What Affects the Cost of Custom Sauna Design & Installation
Every custom sauna is priced to the project, but a few things move the number more than others:
- Size and location. A two-person indoor conversion is a different undertaking than a backyard cabin needing a foundation, a trenched electrical run, and exterior weatherproofing.
- Wood selection. Hemlock and Nordic spruce sit at the accessible end; clear western red cedar, thermo-aspen, and abachi accents carry a premium for their grain, scent, and stability.
- Heater and controls. Electric, wood-fired, and pure steam systems differ in cost, as do digital controls, remote start, and the electrical upgrades some heaters require.
- Glass and lighting. Full glass fronts, frameless doors, custom windows framing a view, and integrated low-voltage lighting add both material and labor.
- Site and structural work. Foundations, framing changes, ventilation routing, drainage, and bringing an older home up to current code all factor into the estimate.
- Permits and inspections. Fees and review timelines vary by your local Marin building department, and we handle the filing and scheduling on your behalf.
After the site visit and design, you get one flat-rate quote covering design, materials, labor, and permits — no hourly surprises.
Cities We Serve
Designing and building for homeowners from San Rafael to the coast.
Trusted by Marin County Homeowners
Frequently Asked Questions
How long does a custom sauna take to build in Marin County?
Most residential projects run four to eight weeks from approved design to first heat cycle, depending on size, materials, and permit timelines. Backyard cabins needing a foundation and outdoor builds take longer; a straightforward indoor conversion can move faster. We give you a real schedule before we start.
Can you build a sauna in a small or unusual space?
Yes — that is exactly where custom shines. We have fit saunas into closets, under stairs, in basement corners, and onto rooftops. After a site visit we will tell you honestly what your space can hold and design the room around it rather than forcing in a stock kit.
Indoor or outdoor — which is better for my home?
Both work beautifully in Marin; it comes down to space and how you want to use it. Indoor saunas are convenient year-round and easy to integrate into a bath or basement. Outdoor cabins create a destination and pair naturally with a cold plunge, garden, or hillside view. We will help you weigh the trade-offs.
Do you handle permits and inspections?
We do. As a licensed general contractor we file through the City of San Rafael or your town’s permit office, coordinate inspections, and build to current electrical, ventilation, and structural code. You should never have to chase paperwork or worry about an install that was not done by the book.
Will the sauna produce real Finnish löyly?
Yes. Proper steam is the whole point, and it depends on engineering most installs skip — sufficient rock mass, correct heater sizing to your room volume, and intake and exhaust vents placed so heat and humidity circulate evenly. We design for that soft, enveloping heat from the start.
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