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LIVE · Studio ·Vol. I ·California Residential Design-Build ·ADUs · Custom Homes · Multifamily ·License & insurance details on request ·CSLB #1156772 ·Starting $250K ·10–16% ROI ·San Francisco · HQ ·Bay Area ·Los Angeles ·LIVE · Studio ·Vol. I ·California Residential Design-Build ·ADUs · Custom Homes · Multifamily ·License & insurance details on request ·CSLB #1156772 ·Starting $250K ·10–16% ROI ·San Francisco · HQ ·Bay Area ·Los Angeles ·
GoldenStateADU
Desk 01 · HQ · Bay Area · JADU

Bay Area JADU Builder. the in-the-house option.

A JADU is the smallest legal Bay Area dwelling — up to 500 sqft, carved from the existing house, with its own entrance and an efficiency kitchen. California state law allows one JADU plus one ADU on every single-family lot, which makes the JADU an underused tool for Bay Area homeowners.

Licensed California contractor · CSLB #1156772 · Bay Area desk · city-by-city review

Begin a Bay Area jadu builder brief →← Back to Bay Area desk

About JADU Builder in Bay Area

We deliver JADUs across SF, Oakland, Berkeley, San Jose, Fremont, and Peninsula cities — typical project $110K–$180K all-in.

Bay Area permit notes · JADU Builder

What we resolve before drawings begin.

  • 01

    Owner-occupancy

    Bay Area JADUs require the owner to occupy either the primary residence or the JADU. We document this during permit application.

  • 02

    Efficiency kitchen rules

    JADU kitchens follow state and local efficiency-kitchen rules — limited counter, limited appliances. We design within these from day one.

  • 03

    City-by-city interpretation

    Some Bay cities interpret JADU rules tightly; others are flexible. We pre-clear interpretation with the planner before drawings start.

ADU intel · the build stack we ship · Bay Area spec

A 2025 LA detached ADU is 12–16 weeks of construction over 6–9 months of permit and design. The fastest path is the pre-approved-plan path — when the design fits.

The manufacturers we actually specify.

  • ZIP System (Huber)

    premium

    USA

    Structural sheathing with integrated weather barrier

    Eliminates a separate WRB step + tape system catches install errors visually. Our preferred default on ADU walls and roof decks.

  • Mitsubishi / Daikin / LG

    premium

    Japan · Japan · Korea

    Mini-split heat pumps for ADU HVAC

    Right-sized inverter heat pumps hit Title 24 and CalGreen with zero ductwork — the cleanest, cheapest HVAC for an ADU < 1,000 sf.

  • Rinnai / Navien

    workhorse

    Japan · Korea

    Tankless water heaters

    Wall-mount tankless saves 9 sq ft of floor and qualifies for SoCalGas rebates when CSA-approved gas units are still permitted; we switch to heat-pump electric where local code requires.

  • Square D / Eaton

    workhorse

    USA

    Sub-panel + load center for ADU service

    Standard 100A or 125A sub-panel from main; tap conductor sizing per CEC 705.12(B).

Material tiers · what you're actually choosing between.

MaterialLifespanInstalled in CABest forTrade-offs
2x6 stick-frame on continuous footing75+ years$340–$520 / sq ft turnkeyMost LA infill ADUs.12–16 weeks construction once permits issue.
Panelized / off-site framing kit75+ years$320–$480 / sq ftTight side-yard sites or fire-rebuilds.Crane access required; not feasible on every lot.
Modular box (Abodu / Cover / Boxabl)50+ years$300–$500 / sq ft delivered + siteworkOwners who want speed and accept the design constraint.Crane + crane-truck access required; foundation still has to be poured first.

Specification gotchas we resolve before contract.

  1. 01

    Pre-approved plans (LA + city catalogs).

    LA City, Santa Monica, Pasadena, Long Beach all maintain pre-approved plan catalogs. Plan check drops to 30 days or less when the plan is in the catalog.

  2. 02

    Utility separation (SB 9 / AB 2221 nuance).

    Separate utility meters are no longer required to permit, but they're often required for refinance or sale. We pull the right meter strategy for the owner's exit plan.

  3. 03

    Fire setbacks + sprinklers.

    ADUs under 1,200 sf often don't trigger sprinklers; over 1,200 or with specific roof tie-ins, NFPA 13D applies.

Sources · CA HCD ADU handbook (2025) · LADBS ADU information bulletin

Other Bay Area services.

All Bay Area services →

Bay Area city directory · 172 cities served

JADU Builder, written for your city.

Each link opens a dedicated page calibrated to the city's permit authority, lot conditions, and price band — not a generic regional landing.

Bay Area · JADU Builder FAQ

Questions Bay Area homeowners ask first.

Start a Bay Area JADU brief. We'll review your city's interpretation, kitchenette layout, and how a JADU pairs with a detached ADU on your lot.

  1. Can I have both a JADU and an ADU on my Bay Area lot?
    Yes — California state law allows one JADU + one ADU on every single-family lot. Many Bay Area homeowners build both for combined rental income.
  2. What does a Bay Area JADU cost?
    Most Bay Area JADUs land $110K–$180K all-in, depending on city, kitchenette layout, and whether a new bathroom is added.
  3. How long does a Bay Area JADU take?
    8–12 months brief-to-keys, depending on the city's review speed.
  4. What's the difference between a JADU and an ADU?
    A JADU is carved from the existing house (max 500 sqft, efficiency kitchen, can share a bath). A standard ADU is fully independent, can be detached, and is not size-capped the same way.
  5. Does owner-occupancy apply to Bay Area JADUs?
    Yes — state law requires the owner to occupy either the primary residence or the JADU. We document this during permit application.
Begin

Begin your projectin twenty minutes.

A short feasibility review of your lot — what you can build, roughly what it costs, and how long it will take. Free of charge. No sales call afterwards unless you ask for one.

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