ADU Contractors in California
Golden State Buildings LLC
16178 E Kings Canyon Rd, Sanger, CA CA 93657
Golden State Buildings LLC, based in Sanger, CA, builds ADUs across Central California. They offer 4 floor plans (420–1,200 sq ft), handle permits, and provide financing options. Free delivery within 50 miles.
read more
Golden State ADUs
930 G Street, Sacramento, CA 95814
Golden State ADUs is a Sacramento-based full-service ADU contractor offering design, permitting & construction. With 10+ years experience and 100+ projects, they build detached ADUs, in-law suites & backyard cottages across California.
read more
Burnette Construction
8100 Otium Way, Sacramento, CA 95843
Burnette Construction offers licensed basement ADU conversion services in Antelope, CA. Specializing in below-grade builds, they handle design, permits, plumbing, HVAC, kitchens, bathrooms, flooring, and separate entry construction for fully compliant accessory dwelling units.
read more
Luma Dwellings Home Builder
63 Hazel Tree Ridge, Orinda, CA 94563
We are a family-first, boutique residential design & build firm serving the Orinda and East Bay community. We’re not just service providers — we’re your neighbors. We understand the local permitting process, the hillside terrain, the fire-hazard restrictions, and the thoughtful planning needed to create homes that truly work for East Bay families.
read more
Hamilton Exteriors
21634 Redwood Road, Castro Valley, CA 94546
Hamilton Exteriors builds detached ADUs, garage conversions, and JADUs across 6 Bay Area counties. Licensed (CSLB #1078806), insured, and bonded. Projects run 5–9 months with fixed-price contracts. CalHFA grants and $0-down financing available.
read more
HBC Construction
41060 High Street, Fremont, CA 94538
HBC Construction, based in Fremont, CA, specializes in ADU building, garage conversions, new homes & additions across the Bay Area. Licensed, code-compliant, full-service from planning to completion.
read more
Alto Builders
5450 Lake Lindero Dr., Agoura Hills, CA 91301
Alto Builders specializes in ADU construction in Los Angeles & Ventura County. Services include detached ADUs, garage conversions & JADUs. Costs range $300–$600/sq ft, with timelines of 5–12 months.
read more
A+ Construction & Remodeling ADU Builders
3612 Madison Ave #33, North Highlands, CA CA 95660
A+ Construction & Remodeling is a top-rated ADU contractor in Greater Sacramento with 30+ years experience. They offer custom ADUs, garage conversions, granny flats & more, managing all permits and zoning compliance. CSLB Licensed #1007869.
read more
Parsa Construction
1105 Fair Weather Circle, Concord, CA 94518
Parsa Construction offers residential & commercial remodeling, ADU construction, and retrofit services. Specializing in kitchen, bathroom, room additions, and accessory dwelling units like granny flats and detached ADUs, they manage permits, design, and build.
read more
DREC Construction Services
15338 Central Avenue, Chino, CA 91710
DREC Construction Services is a licensed ADU builder in Glendale, CA, with 10+ years of experience. They handle design, permitting, and construction of ADUs for rental income, family housing, and home offices, offering a transferable lifetime warranty.
read more
Home Revive Builders
15559 Union Ave #234, Los Gatos, CA 95032
Home Revive Builders is a licensed ADU contractor in the Bay Area, CA, specializing in garage conversions, detached ADUs, in-law suites, and more. Full-service projects include design, permits, plumbing, electrical, and finishing.
read more
ADU San Mateo
3 East 3rd Avenue, San Mateo, CA 94401
At ADU San Mateo, we combine architectural insight, construction experience, and deep knowledge of Bay Area zoning laws to deliver high quality accessory dwelling units from design through move in. Our mission is simple: to make building your ADU clear, fast, and stress free.
read more
Addition Building & Design Inc.
4335 Van Nuys Boulevard, Sherman Oaks, CA 91403
Addition Building & Design Inc. is a Los Angeles design-build firm offering custom home building, additions, renovations, ADU construction, and outdoor living spaces. Their integrated approach covers planning, permitting, and construction for residential projects across LA.
read more
Davis Builders
4283 Rancho Rd, Chico, CA 95973
Davis Builders specializes in designing and constructing custom Accessory Dwelling Units (ADUs) in Chico, CA, providing homeowners with versatile living spaces for rental income or family use.
read more
Bobcat Builders
East Palo Alto, CA 94303
Bobcat Builders is a Bay Area ADU contractor specializing in accessory dwelling units in Palo Alto. They offer attached & detached ADUs, garage conversions, granny flats & in-law suites, backed by a Two Year Satisfaction Guarantee.
read more
Other cities in California
What you need to know
ADU Contractors in California: Navigating the Golden State's Unique Landscape
California is at the forefront of the Accessory Dwelling Unit (ADU) movement in the United States. With one of the most severe housing shortages in the nation, the state has enacted sweeping legislation to make ADU construction more accessible. Since 2020, California laws such as AB 68, AB 881, and SB 13 have significantly reduced barriers, eliminating minimum lot size requirements, reducing setback rules, and streamlining the permitting process. For homeowners looking to add value to their property or create additional rental income, working with experienced ADU contractors in California has never been more important.
What California ADU Contractors Must Know About State Regulations
Professional ADU contractors operating in California must stay current with a constantly evolving regulatory environment. Under California law, local agencies are required to approve or deny ADU permit applications within 60 days. Additionally, ADUs under 800 square feet cannot be denied solely based on floor area ratio limits. Contractors must also be familiar with owner-occupancy rules, utility connection requirements, and fire safety standards that vary by county and municipality. Cities like Los Angeles, San Diego, and San Jose each have their own local ordinances layered on top of state law, making local expertise a critical asset.
Types of ADUs Built by California Contractors
Experienced California ADU contractors are skilled in building a wide variety of ADU types to suit different property configurations and homeowner needs. The most common types include:
- Detached ADUs: Standalone structures built in the backyard or side yard of a primary residence.
- Attached ADUs: Units that share a wall with the main home, often built as additions.
- Garage Conversions: Transforming existing garages into livable spaces, a popular and cost-effective option.
- Junior ADUs (JADUs): Units up to 500 square feet created within the existing footprint of a home.
How to Choose the Right ADU Contractor in California
Selecting the right contractor is one of the most critical decisions in any ADU project. Homeowners should look for contractors who hold a valid California Contractors State License Board (CSLB) license, ideally a Class B General Building Contractor license. It is also important to verify that the contractor carries proper liability insurance and workers' compensation coverage. Look for professionals with a proven track record of successfully permitted ADU projects in your specific city or county.
The Benefits of Building an ADU in California
Building an ADU in California offers significant financial and lifestyle benefits. Homeowners can generate rental income to offset mortgage costs, house family members, or increase overall property value. In high-cost markets like the San Francisco Bay Area or Los Angeles, a well-built ADU can add hundreds of thousands of dollars in property value. With the right California ADU contractor by your side, the process can be smooth, compliant, and highly rewarding.