ADU Contractor San Jose
Licensed & Insured · Free Consultation

ADU Contractor in Campbell, San Jose

Detached ADUs and in-law suites for Campbell's charming small-town suburban homes.

ADU Contractor San Jose·1600 Component Dr, San Jose, CA 95131

Serving the City of Campbell & the neighborhoods around Downtown Campbell.

Licensed & Insured

Full liability & workers' comp coverage

Free Consultation

No-obligation on-site estimates

Design & Permitting

San Jose Municipal Code 20.30.150 compliant

Full-Service Build

Design, permits & construction, start to finish

Our ADU Services in San Jose

Full-service ADU design, permitting, and construction for homeowners across San Jose and Santa Clara County.

Detached ADU Construction in San Jose, CA

Detached ADU Construction

New backyard ADU / granny flat construction, up to approximately 1,200 sq ft, built to San Jose ADU standards

Garage Conversion ADU in San Jose, CA

Garage Conversion ADU

Convert an existing garage into a fully permitted living unit — ministerial approval, typical ~60-day review

Attached ADU in San Jose, CA

Attached ADU

An addition attached to your main home, designed to match the existing structure and roofline

Junior ADU (JADU) in San Jose, CA

Junior ADU (JADU)

Up to 500 sq ft within the existing footprint of your home — an efficient, lower-cost path to added living space

ADU Design & Permitting in San Jose, CA

ADU Design & Permitting

Architectural plans, San Jose Municipal Code 20.30.150 compliance, pre-approved ADU plans program, and full permit handling

Granny Flat / In-Law Suite in San Jose, CA

Granny Flat / In-Law Suite

Multigenerational living units designed for comfort, privacy, and long-term flexibility

Not sure which ADU type fits your lot? Text us for a free consultation.

How It Works

From first idea to a finished, permitted ADU — our simple four-step process.

1

Reach Out

Text us for a free, no-obligation consultation. Tell us about your property, your goals, and your budget.

2

Design & Permitting

We visit your property, assess the lot, and design an ADU plan that fits your site and San Jose Municipal Code 20.30.150. We handle plan submittal and permit approval.

3

Construction

Our experienced crew handles the build — foundation, framing, utilities, and finishes — cleanly and on schedule, keeping you updated at every stage.

4

Move In

Final inspection, walkthrough, and handoff — your new ADU, JADU, or in-law suite is ready for family or tenants.

ADU Investment Guide

Every project is different — these are typical San Jose ranges to help you plan. Your exact price comes with a free, itemized estimate.

Free on-site consultation on every project

Junior ADU (JADU)

Within your home's existing footprint

From $60,000

  • Free on-site consultation
  • Up to 500 sq ft, built within your home
  • Design & San Jose permit handling
  • Efficient kitchenette & living area layout
  • Typically the fastest ADU path
Most Popular

Garage Conversion ADU

Most popular — fast ministerial approval

$80,000 – $150,000

  • Custom design plan for your garage
  • San Jose Municipal Code 20.30.150 compliance
  • Ministerial approval, ~60-day review
  • Full utility & finish upgrade
  • Project management start to finish

Detached / Attached ADU

New backyard unit or home addition

$150,000 – $400,000

  • Custom architectural design
  • Up to ~1,200 sq ft detached ADUs
  • Attached additions matched to your home
  • Full permitting & construction management
  • Granny flat / in-law suite layouts available

Prices vary with size, site conditions, utility connections, and finish level. Design and permitting fees are typically $1,000–$5,000 on top of construction. Contact us for an exact quote — consultations are always free.

Recent ADU Projects in San Jose

A look at real ADU project types from our San Jose team.

ADU framing and construction in progress in San Jose
Finished modern ADU exterior in San Jose, CA
Finished ADU interior living space in San Jose
Construction crew working on an ADU project in San Jose

Campbell & Every Area We Cover

ADU Contractor San Jose serves Campbell and every city and neighborhood across San Jose & Santa Clara County. Explore the interactive map or pick your area below.

Where to Find Us

ADU Contractor San Jose · 1600 Component Dr, San Jose, CA 95131 — serving Campbell

ADU Construction in Campbell, San Jose

Campbell keeps a small-town feel within the greater San Jose metro — walkable Downtown Campbell surrounded by mid-century single-family neighborhoods with well-kept yards. Many Campbell lots have enough backyard depth to support a genuine detached ADU or in-law suite, and the city has actively streamlined its ADU review to encourage exactly this kind of gentle density.

We design Campbell projects to complement the neighborhood's cottage and ranch-home character, then manage plan submittal through the City of Campbell's building department. From a backyard granny flat near downtown to a garage conversion further out, we handle it start to finish. Text us for a free consultation.

Frequently Asked Questions

Everything you need to know about building an ADU in San Jose.

Costs vary widely with size and scope. A garage conversion ADU typically runs $80,000–$150,000, an attached ADU addition $150,000–$300,000, and a new detached ADU $250,000–$400,000. Design and permitting fees are typically $1,000–$5,000 on top of construction. We give you a clear, itemized estimate after a free on-site consultation — text us to get started.

Get Your Free Consultation

Ready to add an ADU, garage conversion, or in-law suite? Text us for a free, no-obligation consultation and estimate anywhere in San Jose & Santa Clara County.

info@aducontractorsanjose.com

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