Top-Rated ADU Near You in San Leandro, CA

ALiGCUS

ALiGCUS

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Minority OwnedMinority Owned
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Valley Habitats Remodeling

At Valley Habitats, Inc., we know that a home reflects its owners—a space where memories are created and traditions cherished. It's also a valuable asset and a significant financial investment. That's why we focus on making every homeowner's building experience smooth, enjoyable, and exceptional. Remodeling a home is an art that demands precision, both on-site and behind the scenes. Meticulous planning, seamless coordination, and a commitment to innovation drive our mission to build lasting relationships wi

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Golden State Designs - ADU Contractor San Jose
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ADU contractors in San Jose CA, ADU builders in San Jose CA

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RCS Pro Build

RCS Pro Build takes pleasure in providing each job with accuracy, skill, and customer-focused service. As a leading remodeling contractor in San Diego, CA, we specialize in complete house remodels, kitchen remodeling, bathroom remodeling, and home additions. Our goal is to turn your vision into a reality with a seamless and stress-free process. With years of experience and a team committed to excellence, we ensure every detail aligns with your style and functional needs. Whether you’re upgrading your kitche

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Royalty Design and Build

Royalty Design and Build, your premier home remodeling company in San Diego. With over 10 years of experience and a reputation for high-quality craftsmanship, we specialize in creating custom spaces that transform homes and improve lives. From full-scale home remodels to specific upgrades like kitchen or bathroom renovations, our expert team of designers, architects, and project managers ensures that every detail aligns with your vision.

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24/7 Handyman Services
Committed to RepairsCommitted to Repairs
Committed to SatisfactionCommitted to Satisfaction
Craftsmanship WarrantyCraftsmanship Warranty
Family OwnedFamily Owned
24/7 Availability24/7 Availability

Since 1997, 24/7 Handyman Services has been San Diego's most trusted provider of comprehensive handyman services. Our experienced professionals specialize in various trades, including painting, plumbing, electrical work, tile installation, stucco and railing, roofing, drywall, and more. Available 24 hours a day, seven days a week, we are dedicated to delivering top-quality craftsmanship and exceptional customer service for all of your residential and commercial property needs.

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Vierra Fine Homes
(*)(*)(*)(*)(*)5.0 (4 Reviews)
Committed Quality ResultsCommitted Quality Results
Craftsmanship WarrantyCraftsmanship Warranty
Fixed PricingFixed Pricing
Free ConsultationsFree Consultations
Locally OwnedLocally Owned

Vierra Fine Homes was founded with a commitment to fostering collaboration among architects, designers, and homeowners, ensuring a unique and positive experience for all involved. Our team shares a deep-seated passion for luxury design and construction, working in unison to create masterpieces that reflect each owner's distinct vision and lifestyle. Our versatile portfolio showcases a profound understanding of diverse project styles, from traditional to ultra-modern. We are adept at handling projects of all

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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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spire architecture inc
(*)(*)(*)(*)(*)5.0 (31 Reviews)

Spire Architecture is a full-service architectural firm dedicated to designing innovative, functional, and timeless spaces. With a commitment to creativity, sustainability, and precision, we craft residential and commercial designs that reflect our clients’ unique vision and lifestyle. Our expertise includes custom home design, renovations, commercial architecture, and interior space planning. From concept development to construction oversight, we ensure a seamless process that integrates aesthetics with fu

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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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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 San Leandro, 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 San Leandro, 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 Vierra avatar

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.

Brett Taylor avatar

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 5, 2026, 4:48:12 AM