Which size fits your lot?
Six steel-framed sizes, 400 to 1,200 sq ft, in your backyard. Call or send the address. We answer with a size, 8 a.m. to 7 p.m., every day.
- CSLB #1158657
- Bond $25,000
- Six sizes, 400–1,200 sq ft
- About 50 miles of San Jose
A detached, steel-framed home in your backyard.
Property review, design, engineering, permitting and site construction in one coordinated path, from the first address to final handoff. Bay Area, within roughly fifty miles of San Jose.
CSLB #1158657 · license held by R&B Master Construction Inc.
Why the frame is steel
Steel gives the project a consistent structural platform. Fire, comfort and durability still come from the whole assembly, not the frame alone.
- Noncombustible
The steel frame does not add fuel to a fire. The fire rating comes from the complete assembly: framing, gypsum, insulation and protection together.
- Does not warp
Steel does not shrink, swell, split or warp as moisture changes.
- Nothing for termites
An inorganic frame is not a food source for termites, and it does not rot.
- Cut before it arrives
Members come pre-cut and pre-punched, so framing on site runs as a repeatable sequence. That shortens framing, not the whole project: review, foundation, utilities and inspections stay on the critical path.
What can actually stand in your backyard?
Six defined sizes and one design study. Your lot decides which one fits.
A second front door
Rent it out to a long-term tenant, or move family in — the build works either way.
- Long-term tenant, not weekend guests.
- Own entrance, own kitchen, one floor.
- Six sizes, 400 to 1,200 sq ft, steel-framed.
Which size fits your lot — send the address, or call.
Which size fits your lot?
Three fields, or one call. We answer with a size and call back from 650-400-7606, 8 a.m. to 7 p.m., every day.
Budget guide: from $250,000 for a compact unit, plus site work.
Six clear stages, address to handoff.
Each stage typically runs one to three months. Permits usually set the total.
Show the six stages
- 01 · Property analysis
We begin with the address, available parcel records, preliminary local rules, visible structures, site geometry, and the items that still need professional verification.
- 02 · Design & product selection
Choose a model direction, layout priorities, finish level, accessibility needs, and project goals. The concept is adapted to the property rather than copied blindly.
- 03 · Architecture & engineering
Architecture, structure, foundation, energy, utilities, and applicable technical requirements are coordinated into a project-specific document set.
- 04 · Permitting & review
The project team submits the coordinated package, tracks agency comments, responds to corrections, and keeps the current review status visible without treating submission as approval.
- 05 · Manufacturing & site preparation
Current framing information, identified members, utilities, access, demolition, grading, foundation work, and required inspections are coordinated around the actual site.
- 06 · Construction & completion
The project moves through foundation, framing, enclosure, utilities, interiors, inspections, corrections, commissioning, and final handoff.
Have a question? WhatsApp us →
Look inside each one
InsideStudio
Why people build one
Four common reasons. TapClick a photo for the next one.
A parent moving in
Own front door, own kitchen, one floor, family still on the same lot.
Long-term rental
Cottage and Residence are drawn for independent family housing and long-term rental.
An adult child, or guests
Studio works as a guest suite, or a room for an adult child back home.
A room for work
Flex has two rooms. One of them can be the office twenty steps across the lawn, with a door that closes.
What homeowners ask first.
Short answers. Anything else, ask on WhatsApp or in the form.
Your lot
Do you build where I live?
Within roughly fifty miles of San José. If your address looks outside that, send it on WhatsApp anyway and we tell you straight.
Will it fit my yard?
The footprints run from 20 × 20 ft (Studio) to 30 × 40 ft (Grand). Setbacks, height, utilities and access are set by your city and the actual site, so online records are only a start; stage 01 lists what still needs professional verification on your parcel.
Money
What does it cost?
From $250,000 for a compact unit, plus site work. Price, placement and permit eligibility remain property-specific, so the figure for your lot comes after the property review.
Can I finance it?
There is no single statewide ADU loan or California-wide ADU rate. Four paths to compare: a home equity loan, a HELOC, a construction or renovation loan, or a cash-out refinance. ADU California is not a lender or a loan broker. Financing options on adu.zone →
Is the CalHFA ADU grant still available?
CalHFA says the latest ADU Grant funding round was fully allocated on December 28, 2023. Treat anyone offering access to that closed round with caution.
Permits
How long does it take?
No universal answer. Each stage typically runs one to three months. Permits usually set the total, and your city, site work, utilities and corrections all move it.
Is submitting the permit the same as approval?
No. We submit the coordinated package, track agency comments and answer corrections, and keep the current review status visible without treating submission as approval.
Which city reviews my permit?
The one with jurisdiction over the parcel, which a mailing address alone does not establish. San José, for example, publishes an ADU Universal Checklist and a staged application process; stage 01 identifies the review path before a model is chosen.
Working with us
Who signs the contract, and who holds the license?
ADU California Inc. signs the contract with you. The work is built under the license listed under Public record, held by R&B Master Construction Inc. Both are named in the consent line of every form on this page.
What happens after I send the form?
We call back from 650-400-7606, 8 a.m. to 7 p.m., every day, or write back on WhatsApp or email if that is what you left. Your details are used to call you back and are not sold or shared.