ADU Contractors in California
IEE Designs
175 Bosstick Boulevard, San Marcos, CA 92069
IEE Designs is a San Diego County design & build firm founded in 1998, specializing in ADU construction and landscape design. Services include detached ADUs, granny flats, casitas, and custom exterior landscaping for residential clients.
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Colibri Kitchen & Bath
5976 Telegraph Ave, Oakland, CA 94609
Colibri Kitchen & Bath offers full-service ADU construction in Oakland, handling design, permitting, and building. Services include site assessment, architectural plans, 3D renderings, and complete construction from foundation to finishing.
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Flip It Homes Inc.
20501 Ventura Boulevard, Woodland Hills, CA 91364
Flip It Homes Inc. is a Southern California ADU builder with 10+ years of experience in garage conversions, new construction ADUs, and home renovations across Los Angeles, San Fernando Valley, and surrounding communities.
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Full Circle Builders
26111 Ynez Road, Temecula, CA 92591
Full Circle Builders offers custom ADU construction in Riverside County & the Inland Empire. Detached ADUs start at $185,000 (590 sq ft, 1BD/1BA). Container homes also available. Turn-key builds, permitting assistance included.
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California ADU Center INC
7542 Laurel Canyon Boulevard, Los Angeles, CA 91605
California ADU Center INC specializes in ADU planning, design, and construction across California. Services include detached ADUs, garage conversions, JADUs, granny flats, and in-law suites. They manage permitting and navigate California's ADU regulations for homeowners.
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Bay Area Home Remodelers
225 Schwerin Street, San Francisco, CA 94134
Bay Area Home Remodelers builds ADUs in Daly City, San Francisco & San Jose. Services include garage conversions, granny flats, JADUs & detached units. Full project support from permits to completion.
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Cali Bath & Kitchen
5519 clairmont mesa blvd, San Diego, CA 92117
Cali Bath & Kitchen offers full-service basement conversions in San Diego. From design to finishing, their in-house crew handles plumbing, electrical, waterproofing & more. Projects take 6–10 weeks. Free consultations available.
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Barzel Builders
4039 Transport Street, Palo Alto, CA 94303
New Birth Builders
11500 West Olympic Boulevard, Los Angeles, CA 90064
New Birth Builders believes that a room addition or Garage Conversion is a great way to increase your home’s value and this new space can be used in a variety of ways. For most homeowners adding a room is less cost efficient and stressful than having to sell their home and move to a bigger home.
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Xavier Design Group
11595 Autumn Sage Avenue, Temecula, CA 91752
An accessory dwelling unit (ADU) is a secondary home on a single-family lot with kitchen, bath, and sleeping space. Xavier Design Group helps Southern California homeowners build ADUs with trusted contractors and transparent pricing.
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Keller Williams Palo Alto
2825 El Camino Real, Palo Alto, CA 94306
Acton ADU is a Bay Area ADU contractor founded by Stan Acton with 30+ years of experience. They offer full-service ADU design, construction, garage conversions, and permitting across San Jose and the broader Bay Area.
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Cronus Service
3429 Freedom Park Drive, North Highlands, CA 95660
Cronus Service offers furnace installation & replacement in Sacramento and Placer County. Turnkey service includes free consultation, removal, ductwork, gas/electric/hybrid install, testing & warranty. Transparent pricing, no hidden fees, same-day completion.
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ResCom ADU, LLC
675 Ygnacio Valley Rd B213, Walnut Creek, CA CA 94596
ResCom ADU is a full-service ADU builder in Walnut Creek, CA, offering design, permits, engineering, construction & hookups. With 100+ years of combined experience, they deliver custom, cost-effective accessory dwelling units using SIPs & Net-Zero technology.
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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.
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Fassino Development
4275 Linda Vista Drive, Fallbrook, CA 92028
California ADUs are self-contained units on single-family lots, offering rental income, family housing, and no land purchase. Build up to 1,200 sq ft. Fassino Development guides homeowners through ADU construction, ensuring local code compliance.
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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.