California ADU Feasibility Checker
Enter a California address to screen ADU feasibility, identify the likely ADU path, review major property constraints, and see what still needs verification.
Enter Your Project Information
Run the tool for an instant preview. Your complete analysis is prepared at the same time and emailed after the report form is submitted.
Building your project analysis…
Checking the inputs, project logic and available source context.
Your detailed report is prepared.
The complete report includes the full checklist, source links, unresolved items, calculations or rule findings, and recommended next actions.
Your complete analysis
A copy has also been sent to your email.
Useful Answers Without Pretending Every Property Is the Same
Tell us about the property
Your address and project details establish the context.
Run the tool logic
Project-specific rules and calculations evaluate the inputs.
Check local context
Official building and planning sources appear when available.
Receive the full report
Preview the result instantly, then email the full analysis to yourself.
What the ADU Feasibility Checker Should Answer
The checker distinguishes detached, attached, garage-conversion and JADU scenarios and evaluates the information supplied about the dwelling, lot, existing structures and proposed unit. The result is criteria-by-criteria rather than a vague yes/no badge.
Use Current California ADU Law as the Statewide Baseline
California HCD maintains current statewide ADU guidance. The tool uses conservative statewide screening logic, then layers local permit and planning sources on top when they are available.
Property-Level Constraints Matter
Lot configuration, existing structures, driveways, pools, slope, access, hazard conditions, historic context and local zoning can affect feasibility. Unknown conditions stay labeled as needing verification.
Strong Tools Explain What Is Known, What Is Estimated, and What Still Needs Verification.
Use the Result Correctly Before You Commit Time or Money
Show the Site Plan Implication
A detached ADU often needs the residence, garage, access path, driveway, parking, property information and proposed unit coordinated on a site plan. Attached ADUs and garage conversions should remain consistent with the architectural set.
Make the Result Explainable
Every major criterion is shown as a positive signal, needs verification, potential constraint or not applicable so the user understands why the tool produced the preliminary outcome.
ADU Feasibility Is More Than Lot Size
Lot size alone does not answer whether an ADU concept is practical. Existing structures, driveway layout, access, parking, property configuration, local implementation rules, hazard constraints and the selected ADU pathway can all affect the next step. The tool therefore treats feasibility as a set of signals and unresolved questions instead of one simplistic pass/fail formula.
How to Improve the Accuracy of Your ADU Result
Use the exact property address, select the correct existing dwelling type, enter a realistic proposed size, and identify known site constraints. If you already have a survey, prior site plan, assessor parcel map or architectural sketch, keep it available for the next review stage. Better source information reduces assumptions and makes the site-plan scope more precise.
What to Do After a Promising ADU Screen
A promising result should move into property-level coordination before design work becomes expensive. Confirm the local permit pathway, verify unresolved property conditions, define the proposed ADU footprint, and prepare a site plan that shows the existing residence, garage, access, parking and other relevant improvements.
California ADU Feasibility Checker FAQs
These answers explain how to interpret the tool and when local or professional verification still matters.
Can this tool tell me with certainty that I can build an ADU?
No. It provides a preliminary feasibility screen and identifies local sources and unresolved property conditions that still need confirmation.
Does California have statewide ADU rules?
Yes. California has statewide ADU law, while local jurisdictions administer permits and may publish compliant local ordinances and procedures.
Can I check a garage conversion?
Yes. Garage conversion is a separate pathway because the property and building relationships differ from a new detached ADU.
Will the result include setback information?
It can show local-source links and user-entered setback information and flags exact property setbacks for verification when reliable parcel-level data is not available.
What happens after the feasibility check?
You can save/email the result or move into an ADU site-plan quote with the property and project information carried forward.
Does a promising result mean the ADU will fit physically?
Not necessarily. A concept or site plan is still useful for checking how the proposed unit relates to the actual property and existing improvements.
Can I use the tool before hiring a designer?
Yes. Early screening can help identify questions worth resolving before design work begins.