Top-Rated ADU Near You in Santa Monica, CA

Brother & Brother Builders
(*)(*)(*)(*)(*)4.9 (156 Reviews)

Brother & Brother Builders is a trusted general contracting company specializing in high-quality residential remodeling and construction services throughout the Bay Area. With years of experience and a commitment to craftsmanship, we help homeowners bring their vision to life with precision, creativity, and care. Our services include kitchen and bathroom remodeling, home additions, garage conversions, ADUs, and full-home renovations. From design to completion, our team ensures a smooth, transparent process

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L E Construction General Building Contractor Inc
(*)(*)(*)(*)(*)5.0 (13 Reviews)
Beat Match PricesBeat Match Prices
Committed Quality ResultsCommitted Quality Results
Free EstimatesFree Estimates
Years in BusinessYears in Business

L E Construction is a licensed and bonded General Contractor serving residential and commercial customers throughout Ventura County since 1999. In addition to general contracting services they specialize in remodeling and solar installation. Transform your home with L E Construction! Our expertise extends to ADUs, Bath Remodeling, Kitchen Remodeling, Room Additions, New Construction, Outdoor Living Spaces, and a full range of services including Decks, Patio Covers, Carpentry, Concrete, Stucco, Tile, Floorin

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SR Freeman Inc. - North Bay Division
Committed Quality ResultsCommitted Quality Results
Committed to RepairsCommitted to Repairs
Committed to SatisfactionCommitted to Satisfaction
Craftsmanship WarrantyCraftsmanship Warranty
Fixed PricingFixed Pricing

At SR Freeman, we have built a 30+ year reputation as the premier custom home framing partner in the Bay Area.  We help general contractors’ complete high-end residential projects with precision, reliability, and seamless integration of structural steel and framing. Our proactive approach, deep industry expertise, and commitment to quality ensure your projects run smoothly on time, and with outstanding craftsmanship. Let us discuss how we can help make your next project a success.

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Michael W. Folonis Architects
Committed Quality ResultsCommitted Quality Results
Consultations AvailableConsultations Available
Locally OwnedLocally Owned
Veteran OwnedVeteran Owned
Years in BusinessYears in Business

The philosophy at Michael W. Folonis Architects is to engage in a constant working awareness of Culture, Technology, History, Sustainability and Social Relevance. We employ these fundamental components in every stage of research, design and development. Counter to the throwaway culture of today, MWFA establishes a permanent architectural character, grounding each structure to the land and responding to a project’s unique set of conditions. Design is not begun with preconceived assumptions. Rather, design so

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Riviera Plumbing LLC

We pride ourselves on reliability, great communication, integrity and quality work. We are experts in our trade and will do our best to keep you as educated as we can on your particular task or project. All of our services come with the same promise of quality, dedication, and durability. We only work with the best materials available and will never compromise quality for time. At Riviera Plumbing, we always give our clients realistic schedules that accommodate their lives. We look forward to earning your

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Paint Me
LETTER FOUR, INC.
BoutiqueBoutique
Committed Quality ResultsCommitted Quality Results
Eco-FriendlyEco-Friendly
Free ConsultationsFree Consultations
Woman OwnedWoman Owned

From major remodels and additions to new construction, Letter Four's residential and commercial clients across Southern California benefit from our in-house expertise in architecture, interior design and licensed general contracting. From permits and plans to the last lick of paint, we provide a matchless combination of continuity, creativity and craftsmanship. This is design-build as it should be: a seamless, simple and stress-free journey to the space of your dreams.

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Architecture JHK, Inc.
(*)(*)(*)(*)(*)5.0 (17 Reviews)
Available by AppointmentAvailable by Appointment
BoutiqueBoutique
Budget-FriendlyBudget-Friendly
Eco-FriendlyEco-Friendly
Established inEstablished in

Architecture JHK is a Los Angeles-based boutique design firm with over 20 years of experience specializing in custom homes. Our mission is to partner with you the homeowner to make your vision a reality with the aesthetic style, function, and value you desire in your dream home. We are dedicated to the power of built and natural environments to impact the way we live, especially how we foster connections with each other. Our highest ideals center in the application of timeless architectural design aesthetic

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A Custom Electric

In business since 1995. We at A Custom Electric, are a full service electric company. Our electrical services include new construction electrical work for both residential and commercial buildings as well as remodel and job specific electrical installations and repairs. We take pride in our workmanship because we have A Commitment To Excellence. We provide personalized electric service for each of our customers with first class electrical service, with free estimates and reasonable prices for all your resid

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ZAD Studio LLC
Available by AppointmentAvailable by Appointment
Committed to SatisfactionCommitted to Satisfaction
Consultations AvailableConsultations Available
Hourly PricingHourly Pricing
LuxuryLuxury

“Transforming Spaces, Crafting Experiences”: As an interior architect, I blend aesthetics, functionality, and innovation to create captivating environments that resonate with your vision. Our services cover Residential, Commercial & Hospitality project. Interior Design, Interior Architect

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ADU FAQs

An Accessory Dwelling Unit (ADU) is a secondary residential unit on the same property as a primary home. Common examples include detached ADUs (freestanding structures), attached ADUs (connected to the main house), or garage conversions. Homeowners often build ADUs to:

  • Accommodate aging family members or adult children.
  • Generate rental income as a long-term investment.
  • Increase property value through additional living space.

If you're considering an ADU, it’s important to evaluate your property’s zoning regulations and infrastructure to ensure compliance with local laws.

The cost of building an ADU varies depending on size, materials, location, and complexity. On average, homeowners spend $50,000 to $250,000 on an ADU. Here’s a breakdown:

  • Garage Conversions: $50,000–$100,000
  • Attached ADUs: $100,000–$200,000
  • Detached ADUs: $150,000–$250,000+

Keep in mind that factors like design customization, permits, and site preparation can increase total costs. Always request detailed quotes from multiple contractors to ensure accurate estimates.

In Santa Monica, you’ll typically need zoning and building permits to construct an ADU. Depending on your city or county, you may also have to submit:

  • Site plans
  • Utility connection approvals
  • Engineering or structural reports

Check your local building department’s website or contact a professional ADU contractor who can guide you through the permitting process. Accurate documentation and upfront compliance can save you time and penalties during the construction phase.

The timeline for building an ADU typically ranges from 6 months to 18 months. Here’s an overview of the stages:

  1. Design and Planning: 2–4 months (including permits and engineering approvals)
  2. Construction: 3–9 months (actual building and inspections)
  3. Finalization: 1–3 months (finishing touches, landscaping, approvals)

Timelines can vary based on project complexity, contractor availability, and your local building department’s approval process.

When hiring an ADU contractor, look out for the following red flags:

  • Refusal to provide proof of licensing or insurance.
  • Lack of experience with ADU projects.
  • Lowball estimates that seem too good to be true.
  • Contractors asking for large upfront payments before starting work.
  • Poor communication or unwillingness to provide a clear project timeline.

Always read reviews, request references, and verify your contractor’s credentials with your state licensing board before signing a contract.

To ensure your ADU complies with building codes, follow these steps:

  1. Consult Local Regulations: Research the zoning and building ordinances in your city or county.
  2. Hire a Reputable Contractor: Partner with a builder experienced in ADU projects within your area.
  3. Obtain Necessary Permits: Secure all required permits from your local building department before breaking ground.
  4. Schedule Inspections: Allow inspectors to evaluate the project at key stages to confirm compliance.

For specific building code inquiries, visit the International Code Council (www.iccsafe.org) or consult your local building authority.

In Santa Monica, many homeowners are allowed to rent out their ADUs, but rental regulations can vary significantly depending on local laws. Common requirements include:

  • Securing a rental license or registration.
  • Complying with maximum occupancy rules.
  • Following rules regarding short-term rentals (e.g., Airbnb).

It’s important to verify rental guidelines with your city or county housing authority before listing your ADU to ensure compliance and avoid fines.

A Junior Accessory Dwelling Unit (JADU) is a smaller, more compact version of an ADU, typically limited to 500 square feet. Key differences include:

  • JADU: Often repurposes existing space within the primary residence (e.g., a spare bedroom or garage) and may share facilities like a bathroom or kitchen.
  • ADU: Can be a completely separate structure with its own kitchen, bathroom, and entrance.

JADUs are ideal for limited spaces or lower budgets, while standard ADUs offer more independence and privacy for tenants.

Converting a garage into an ADU is often a cost-effective and efficient way to add livable space because:

  • The existing structure reduces construction costs.
  • Garage conversions often bypass strict zoning restrictions.
  • They provide an opportunity to repurpose underutilized space.

However, you’ll need to ensure the garage meets structural and insulation requirements, and you may need to relocate utilities or parking spaces. Consulting a professional is key to a successful conversion.

Financing an ADU can be accomplished through various methods, including:

  • Home Equity Loans/HELOCs: Borrowing against the equity in your home.
  • Cash-Out Refinancing: Refinancing your mortgage to access additional funds.
  • Personal Loans: Unsecured loans with flexible terms for smaller projects.
  • Government Grants or Subsidies: Some states and cities offer financing assistance for ADUs.

Work with a financial advisor to choose the funding method that best fits your budget and long-term goals.

Reviews for ADU

Seamless ADU Conversion in San Diego
Our garage was just collecting dust, but this service made starting an ADU conversion effortless. Within a day, we had three competitive bids from local pros. We picked one, and in under four months, our ADU was fully finished, bringing in rental income already!
Lisa H.
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Quick Fix for Zoning Snags
We hit a roadblock with city permits for our backyard ADU in Austin. The contractor we found through the platform knew exactly how to address zoning challenges and fast-tracked the process. We’re now ahead of schedule and saved thousands in potential delays.
Mark J.
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Dream ADU, Zero Stress
Converting our basement into an ADU felt overwhelming at first, but this service connected us with an expert in Boston in less than an hour. They handled everything from design to build, and we finished well under budget. It’s already a cozy space for my mother-in-law to move into!
Sarah P.
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Maria VierraEditor

Maria Vierra is the lead designer at Vierra Fine Homes, bringing over two decades of experience in high-end residential design and construction. Her expertise and attention to detail ensure every project meets the highest standards of excellence, blending functionality with aesthetic appeal.

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Brett TaylorAuthor

Brett Taylor is the co-founder of The Builder Market and a visionary entrepreneur in the home services and construction industries. With a passion for innovation, Brett has played a pivotal role in revolutionizing how professionals and homeowners connect and collaborate.

This page was last updated on Jan 7, 2026, 8:59:44 AM