Property check
Start with your California property address. Explore ADU potential, available lot details, zoning, and local rules—with clear next steps.
Free preliminary review. No credit card required.
Enter a complete California address to review available public parcel records.
Explore lot details, zoning, utilities, easements, and local ADU rules.
Review preliminary ADU options, planning estimates, and your next steps.
Architectural concept · natural daylight
More room for lifeFamily, flexibility and rental potential
One coordinated pathProperty review through construction
Steel at the coreNoncombustible framing material · What this means
Planned for your siteLocal rules, access and utility review
Designed for today.
Built for tomorrow.
Inside ADU California Inc
See the manufacturing equipment behind our steel framing, then take a look at a residential steel-frame build in progress.
ADU models · small to full-size
Compare six defined models with sizes, rooms, and typical planning ranges. Check your property to see which footprint is worth exploring. Images are design concepts.
Explore all 6 ADU models
400 sq ftView details Modern compact
Guest suite, home office, or rental studio
Typical planning range
$197,500 – $264,000
Standard finishes + steel framing. Baseline allowances included; site-specific work and utility upgrades may add cost. Preliminary, not a quote.
600 sq ftView details California cottage
Long-term rental or independent family housing
Typical planning range
$302,500 – $405,500
Standard finishes + steel framing. Baseline allowances included; site-specific work and utility upgrades may add cost. Preliminary, not a quote.
750 sq ftView details Flexible contemporary
Small families, shared office, or higher rental flexibility
Typical planning range
$384,000 – $515,500
Standard finishes + steel framing. Baseline allowances included; site-specific work and utility upgrades may add cost. Preliminary, not a quote.
850 sq ftView details Warm contemporary
Multigenerational living or premium rental use
Typical planning range
$449,500 – $602,000
Standard finishes + steel framing. Baseline allowances included; site-specific work and utility upgrades may add cost. Preliminary, not a quote.
1,000 sq ftView details Modern backyard home
Primary-quality family living or long-term rental
Typical planning range
$523,000 – $702,000
Standard finishes + steel framing. Baseline allowances included; site-specific work and utility upgrades may add cost. Preliminary, not a quote.
1,200 sq ftView details Premium modern residence
Larger families and high-capacity multigenerational living
Typical planning range
$630,500 – $846,000
Standard finishes + steel framing. Baseline allowances included; site-specific work and utility upgrades may add cost. Preliminary, not a quote.
Concepts 1 of 6
Planning footprints. All six models have defined dimensions for a preliminary map test.
Model views. Explore exterior and interior views for each model.
Property-specific next step. Placement, design, pricing, and permits require verification for the site.
Build your ADU with us
Bring us your address and goals. ADU California Inc. coordinates property review, design, engineering, permitting, steel framing, construction, and final handoff around your project.
Review the property, compare model footprints, clarify the goal, and define the concept worth developing.
Result of this phase
Property direction + selected model baseline
Coordinate architecture, engineering, utilities, local review, permitting, manufacturing information, and site readiness.
Result of this phase
Project-specific documents + readiness gates
Move through frame assembly, enclosure, utilities, interiors, inspections, corrections, and final handoff.
Result of this phase
Completed ADU + closeout information
Steel-frame manufacturing begins only from the approved project information. Site, design, engineering, permitting, and revision control remain property-specific.
Why the system matters
ADU California Inc. connects early property decisions to a defined model, project-specific engineering, steel framing, and construction coordination.
Explore steel technologyThe address, site geometry, visible constraints, and unresolved records shape the conversation before a final scope is proposed.
Our six planning models have defined footprints and room programs. The separate two-storey design study remains in development.
Architecture, engineering, frame information, enclosure, utilities, and site work follow one controlled project path.
Preliminary, verified, customer-confirmed, and professional-review information stays clearly labeled as the project develops.
Preliminary cost planning
Compare broad construction ranges after choosing a project type, size, finish level, and site assumptions.
Open cost calculatorModel and size
Used to build an early planning range—not a contract price, bid, or approval.
Finish and site assumptions
Used to build an early planning range—not a contract price, bid, or approval.
Cost and timeline range
Used to build an early planning range—not a contract price, bid, or approval.
Homeowner questions
Start with what is known, keep preliminary information labeled, and verify the site-specific facts before making a construction decision.
No single online check can guarantee that. Zoning, parcel geometry, setbacks, existing structures, easements, utilities, access, hazards, local review, and project-specific engineering can all affect the final answer.
No. Models with defined footprints are starting concepts; the two-storey design study still needs a measured plan. Final architecture, engineering, foundation, energy, utility, fire, and permit documents must be adapted and approved for the specific site.
Cost depends on model size, design changes, finishes, utilities, access, grading, demolition, jurisdiction, and site conditions. The calculator provides an early planning range, not a bid or contract price.
For a straightforward detached steel-frame ADU, our current planning model allows 1–2 months for design and engineering, 2–4 months for permitting, and 7–10 months for construction (10–16 months overall). These are preliminary planning allowances, not guaranteed or measured completion times. Corrections, agency workload, utility upgrades and difficult site conditions can extend the schedule; we confirm a project-specific schedule after review.
The project path can include property review, model selection, design, engineering coordination, permitting, steel-frame information, site preparation, construction, inspections, and closeout. The exact contracted scope must be confirmed for each project.
Online information is preliminary. The team can help identify which records, local confirmations, surveys, or professional reviews are needed for the next decision.
Also available
Explore non-residential steel-frame design concepts on their own page. Designs, permits and pricing are developed for your property.
