Detached ADU near Mill Valley, CA

Urban Building Workshop is a full-service architecture firm in the Bay Area specializing in custom homes, remodels, and ADUs. Experts in Marin County, San Francisco, and Sonoma County permitting, they deliver efficient, light-filled designs.

Haus+ is a Bay Area ADU builder offering turnkey accessory dwelling units for California homeowners. They handle design, permitting, and construction using a panelized hybrid method, with all-inclusive upfront pricing and in-house financing availa... read more

Lion ADU Builders is an Oakland ADU contractor offering detached ADUs, garage conversions, in-law suites, and custom builds. They manage design, permits, and construction, helping homeowners add space and property value across the Bay Area.

NorCal ADU Builders is a California-based full-service ADU contractor handling planning, permits, Title 24 compliance, and construction—including foundation, framing, roofing, plumbing, and interior finishes—for detached ADUs, garage conversio... read more

prefabADU is a Bay Area ADU builder with 16+ years of experience offering affordable kits and plans from under $45K. With 12 state-approved plans valid across California, they simplify permits, design, and installation for homeowners.

Regency Construction & Remodeling BA is a San Francisco ADU contractor offering new builds, space conversions, and prefab ADU solutions. They handle design to completion, manage permits, and ensure compliance with local zoning laws.

Vargas Construction is a California ADU contractor offering detached, attached, garage, junior, and multifamily ADUs. They handle design, permitting, and construction with energy-efficient materials, custom interiors, and full amenities in 2–6 m... read more

HDR Remodeling is a Bay Area Design Build firm since 1987, specializing in kitchen remodels, bathroom renovations, and home improvements across Oakland, Berkeley, Alameda, and the East Bay, backed by an experienced team of architects and designers... read more

Shed Shop offers ADUs (Accessory Dwelling Units) via their Mini Cottage program. Sizes range from 192 to 480 sq. ft. Services include foundation, plumbing, electrical, permits & more. Available in select cities.

Dan Boyle Construction offers expert ADU construction in Santa Rosa & Sonoma County. With 30+ years experience, they handle site evaluation, permits, design & full builds for detached ADUs, granny flats & backyard cottages.

Wellmade is a California prefab ADU builder specializing in panelized accessory dwelling units. Founded in 2020, they've completed 200+ projects, reducing construction waste by 85%. Serving CA, OR, and WA with all-inclusive pricing.

Metricon Homes offers ADU construction and garage conversion services. Choose from 5 sizes: Marigold, Camellia, Magnolia, Dahlia, and Sunflower. Their Design to Doorstep process covers custom design to completion. Licensed contractor: Tobin Brinke... read more

Geico Builders offers ADU services including detached ADUs, attached ADUs, Junior ADUs, garage conversions, and home additions. Ideal for rental income, family housing, or maximizing space on your existing property.

Eagle ADU is a licensed ADU builder in Northern California offering three signature models: Eagle Studio ($180K–$220K), Eagle One ($230K–$280K), and Eagle Two ($310K–$360K), with rental income potential up to $4,000/month.