What We Build
ADU Construction Across San Francisco, Marin & Napa
Accessory dwelling units navigated through SF's notoriously complex codes, Marin's hillside rules, and Napa's agricultural overlays — done right the first time.
Why Build an ADU
One structure. A measurable return on your land.
An accessory dwelling unit is the most efficient way to extract real value from a Bay Area or wine-country lot. Rental income that offsets a mortgage. A private suite for aging parents or returning adult children. A flexible studio, office, or guest house that adapts as your life does.
Done correctly, an ADU also adds lasting resale value to the primary property — and unlike a remodel, it creates an entirely new, independently livable address on land you already own. The difference between a smart investment and an expensive mistake is a builder who knows the codes cold.
Section 01 — The Case for an ADU
Four ways an ADU pays you back.
Rental Revenue
A detached or attached unit can generate steady monthly income in some of the highest-rent markets in the country — often covering a meaningful share of the primary mortgage.
Multigenerational Living
Independent, dignified space for aging parents or adult children — close enough for connection, private enough for everyone's autonomy.
Property Value
A permitted, well-built ADU adds durable resale value and broadens the pool of future buyers who want flexibility built in.
Adaptable Use
Home office, studio, guest house, gym, or rental — a single well-planned unit can change roles as your needs change over the years.
Section 02 — Local Code Expertise
The rules are completely different in every market.
An ADU contractor in San Francisco faces a different rulebook than one in Marin or Napa County. Robin and her team build in all three — and knows exactly where each jurisdiction trips people up.
The Most Complex ADU Codes in California
San Francisco has some of the most intricate ADU regulations in the state, and an ADU contractor in San Francisco has to know them cold. Layered Planning Code controls, neighborhood density limits, rear-yard and open-space requirements, mandatory pre-application screening, Section 311 neighbor notification, and the distinction between state-mandated and local ADU programs all shape what's actually buildable on a given lot. Robin reads these rules fluently and designs to them from the first sketch — so the permit clears instead of stalling.
Hillside & Fire-Zone Constraints
Marin's wooded hillsides bring slope-stability review, grading limits, and strict design controls — and most parcels sit inside Very High Fire Hazard Severity Zones. That means ignition-resistant assemblies and defensible-space planning aren't optional add-ons; they're baked into approval. Robin engineers the structure and the site together.
Agricultural Overlay & Lot Rules
Building an ADU in Napa County means navigating agricultural-preserve overlays, minimum lot-size and setback rules, and well and septic capacity on parcels that often sit outside municipal services. Robin coordinates the percolation, water, and code review up front so an ADU Napa County project doesn't stall at the health department.
Section 03 — Types We Build
Every ADU configuration, matched to your lot.
Detached New ADU
A free-standing, purpose-built unit sited for privacy, light, and access — the most flexible option where the lot has the room for it.
Garage Conversion
Turning existing garage square footage into a fully permitted living unit — often the fastest, most cost-efficient path to an ADU.
Junior ADU (JADU)
A compact unit carved from the existing home's footprint, with its own entrance and efficiency kitchen — a streamlined path under both state and local rules.
Attached Addition
New conditioned space built off the primary residence, sharing a wall but functioning as an independent, separately accessed dwelling.
Above-Garage Unit
A second-story unit built over a new or existing garage — recovering value from vertical space without consuming yard or setback area.
Section 04 — Built to a Higher Standard
Green and fire-resistant from the foundation up.
A second dwelling is a chance to build the way every home should be built — efficient, durable, and engineered for the realities of Northern California.
- High-performance envelope — tight, well-insulated assemblies that keep operating costs low for you or your tenant.
- All-electric & solar-ready — designed to meet today's energy codes and tomorrow's, with electrification built in.
- Green building expertise — drawing on Robin's work as USGBC LEED for Homes pioneer. Explore green building & LEED.
- Fire-resistant detailing — Class A roofing, ignition-resistant cladding, and ember-resistant vents where the hazard zone requires it.
- Defensible-space planning — Zone 0–2 clearances integrated into the ADU's siting from day one.
- One coordinated system — green and fire-hardening specified together. See fire-resistant construction.
Section 05 — Why It Matters
The permit process is where ADUs are won or lost. Knowing the code before the first drawing saves clients months of delay and tens of thousands in rework.
Robin designs every ADU to its jurisdiction's actual requirements from the outset — so the application moves, the budget holds, and the build starts on schedule.
By the Numbers
Thirty years across three markets.
Schedule a Free ADU Consultation
Whether your lot is in San Francisco, Marin, or Napa County, Robin will walk the site, the code, and the numbers with you before you commit a dollar.