ADU Contractors near Mill Valley, CA
DSA Architects
1107 Virginia Street, Berkeley, CA 94702
14.3 miles
DSA Architects designed an 850 sq. ft. second-floor ADU in Berkeley Hills for multi-generational living. Features 2 beds, 1 bath, open layout, Tilden Park views, roof deck, solar PV, heat pumps, and gray-water system.
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BuildZig ADU Services
3007 Telegraph Avenue, Oakland, CA 94609
20 miles
BuildZig ADU Services is a Bay Area ADU contractor specializing in design, permitting, and construction. They handle garage conversions, detached ADUs, basement/attic conversions, and more, offering transparent pricing throughout.
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San Francisco ADU Solutions
967 Connecticut Street, San Francisco, CA 94107
11.1 miles
ADUs (accessory dwelling units) are self-contained homes on existing properties. California's 2020 laws simplified ADU permits statewide. Alpha ADU Solutions, a San Francisco-based ADU builder with 100+ team members, specializes in granny flats, g... read more
Vitalize Build
3120 Scott Blvd, Suite 130, Santa Clara, CA 95054
48.5 miles
Vitalize Build is a Bay Area ADU contractor offering design and construction services for detached ADUs, garage conversions, and in-law suites. They provide preapproved, predesigned, and custom layouts ranging from 238 to 1,200 sq ft.
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Wise Builders
2355 Paragon Drive, San Jose, CA 95131
49.7 miles
Wise Builders is a Bay Area ADU contractor with 20+ years of experience in accessory dwelling units, garage conversions, and attached or detached ADU construction across San Jose, Sunnyvale, and Silicon Valley. Free estimates available.
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ProStruct Engineering
450 Folsom Street, #1502, San Francisco, CA 94105
11 miles
ProStruct Engineering offers ADU structural engineering services across California, providing permit-ready plans and calculations for detached ADUs, garage conversions, granny flats, and more, with a 2–3 week turnaround.
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Metricon Homes
2010 Crow Canyon Road, Suite 100, San Ramon, CA 94583
32.3 miles
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
Edrington and Associates
5944 Claremont Avenue, Oakland, CA 94618
16.3 miles
Edrington and Associates helps property owners add ADUs—garage conversions, detached units, or Junior ADUs. They offer ADU Feasibility Studies in three packages and a free 15-minute consultation to explore options.
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Roof and Realm
2245 Vía De Mercados, Concord, CA 94520
27.2 miles
Roof and Realm is a California-based steel-framed modular home and ADU builder offering fire, earthquake, and wind-resistant structures. Their eco-friendly builds use 98% recyclable materials, generate minimal waste, and support solar-ready, Net P... read more
Greenwood Custom Builders, Inc.
765 Old County Road, San Carlos, CA 94070
32.4 miles
Northbay Home Solutions
47 Paul Drive, San Rafael, CA 94903
3.7 miles
Northbay Home Solutions offers full-service ADU construction in San Rafael, San Francisco & North Bay. Services include detached ADUs, garage conversions & JADUs, covering design, permits & build.
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Regency Construnction & Remodeling BA
The Paramount, 95 3rd St, San Francisco, CA 94103
11.4 miles
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.
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UDA ADU
Palm Avenue, Los Altos, CA 94022
43.8 miles
UDA ADU is a California ADU contractor specializing in detached ADUs, garage conversions, JADUs, and in-law suites. They handle design, permitting, and construction, offering homeowners a streamlined, full-service ADU building experience.
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New Avenue, Inc
2120 University Avenue, Berkeley, CA 94704
15.2 miles
New Avenue, Inc is a full-service design-build company serving the San Francisco Bay Area and Portland, OR since 2011. They specialize in ADUs, custom homes, renovations, additions, and Enclaves, managing design, permitting, and construction under... read more
Tiny House Basics
5433 Clayton Road, Clayton, CA 94517
32.3 miles
Tiny House Basics designs custom tiny house trailers with insulated floors, no thermal bridging, and build-ready delivery. Models range from 10–50ft, up to 12ft wide, in bumper pull or gooseneck styles. Lifetime consulting included.
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Other cities in California
What you need to know
Building ADUs in Mill Valley: Navigating a Hillside Community
Mill Valley, nestled in the scenic hills of Marin County just north of San Francisco, presents a unique set of challenges and opportunities for ADU contractors. Known for its dense redwood forests, steep terrain, and architecturally distinctive homes, Mill Valley requires experienced ADU professionals who understand the complexities of building on hillside lots, working around mature trees, and complying with both California state ADU laws and the City of Mill Valley's local regulations.
Local Regulations and Permitting for ADUs in Mill Valley
Mill Valley falls under the jurisdiction of the City of Mill Valley Community Development Department, which oversees ADU permitting. While California state law (AB 68, AB 881, and SB 13) has significantly streamlined ADU approvals statewide, Mill Valley still enforces specific local standards that contractors must navigate carefully. Key considerations include:
- Fire hazard zones: Much of Mill Valley is located within a Very High Fire Hazard Severity Zone (VHFHSZ), requiring ADUs to meet strict fire-resistant construction standards, including ember-resistant vents, Class A roofing, and defensible space requirements.
- Tree protection ordinances: Mill Valley has strong protections for heritage and protected trees. ADU contractors must often work around significant root zones and may need arborist reports before breaking ground.
- Steep slope regulations: Many parcels in Mill Valley have slopes exceeding 15–25%, which can trigger additional geotechnical studies and grading permits.
- Setback and height requirements: Local zoning may impose setback rules and height limits that vary by zone, requiring careful site analysis before design begins.
Types of ADUs Commonly Built in Mill Valley
Given the nature of Mill Valley's existing housing stock — largely single-family homes with garages, basements, or detached structures — the most popular ADU types in the area include:
- Garage conversion ADUs – Converting an existing attached or detached garage into a living unit is a cost-effective option popular in Mill Valley neighborhoods.
- Detached ADUs – Standalone units built in backyards, though hillside lots often require custom foundation solutions such as pier-and-grade beam systems.
- Junior ADUs (JADUs) – Units of up to 500 square feet created within the existing footprint of a primary residence.
Choosing the Right ADU Contractor in Mill Valley
Selecting a qualified ADU contractor in Mill Valley means finding a professional with demonstrated experience in Marin County's regulatory environment. The right contractor will be familiar with the Mill Valley Building Division, understand fire-safe construction methods, and have relationships with local engineers and arborists. Look for contractors who are licensed by the California Contractors State License Board (CSLB) and who have a proven portfolio of completed ADU projects in hillside communities similar to Mill Valley.
Investing in an ADU in Mill Valley can significantly increase your property's value and provide rental income in one of the most desirable communities in the San Francisco Bay Area. With the right contractor, the process can be smooth, code-compliant, and tailored to the unique character of your Mill Valley property.