California ADU Eligibility Checker
California has the most permissive statewide ADU framework in the country. If you own a single-family lot and the structure you propose fits the state's size limits, the state's position is that your city must approve it — and in most cases within 60 days. The tool below walks through the handful of situations where state law still leaves gaps, mostly around zoning overlays and existing non-conforming structures.
ADU Eligibility Checker
Find out if you can build an ADU on your property. Enter your details below for an instant assessment based on state and local regulations.
Property Details
Eligibility Assessment
California · 6,000 sq ft lot · Single-Family zoning
Your property appears to meet state-level ADU requirements
Allowed ADU Types
Maximum ADU size: 1,200 sq ft
Key Rules & Restrictions
California ADU Legislation
Key legislation: AB 976 (2024), SB 543 (2025)
- •AB 976 eliminated owner-occupancy for ALL ADU types effective January 1, 2024
- •SB 543 (2025) includes deemed-approved mechanism for delayed permits
- •AB 462 provides 60-day deemed-approved for coastal zone ADUs (effective Oct 10, 2025)
- •HOAs cannot restrict ADU construction under state law
- •CalHFA ADU Grant ($40K) is CLOSED — fully allocated December 2023
- •1 ADU + 1 JADU allowed per single-family lot; multi-family allows up to 2 detached ADUs
Recommended Next Steps
Important: This is general guidance based on state law. Local ordinances, overlay zones, and specific property conditions may affect eligibility. Always verify with your local planning department before starting any ADU project.
How California ADU Eligibility Works
California's ADU statutes — chief among them Government Code Sections 65852.2 and 65852.22 — preempt most local barriers. On any residentially-zoned lot with an existing or proposed primary dwelling, the state requires your city to allow at least one ADU plus (on single-family lots) one JADU. The calculator marks California green for almost any configuration because the state overrides historical blockers that still trip up owners in Texas, Florida, and other states without mandates: minimum lot size cannot be imposed for 800-square-foot ADUs, owner-occupancy cannot be required (AB 976, effective January 2024), setbacks cannot exceed four feet, parking replacement cannot be required when converting a garage, and HOAs are expressly preempted from banning or effectively banning ADUs.
Where the Yellow Lights Come On
The calculator returns a yellow traffic light in a handful of California-specific scenarios. First, coastal zone parcels still require Coastal Commission review under the Coastal Act, though AB 462 (effective October 10, 2025) imposes a 60-day deemed-approved clock that has substantially reduced the drag. Second, historic districts and historic-eligible properties face case-by-case design review even though the underlying zoning allows ADUs — plan on 2–4 additional months and a preservation architect. Third, properties with existing code violations on the primary dwelling or prior unpermitted construction sometimes get held up while those are resolved. Fourth, fire hazard severity zone properties face additional defensible space and ignition-resistant construction requirements that don't block the ADU but do raise the cost side of the equation.
What Changed Recently
Several California bills over the last two years materially expanded ADU rights. AB 976 (2024) eliminated owner-occupancy for all ADU types permanently, removing the biggest remaining structural barrier for investors. SB 543 (2025) added a deemed-approved mechanism for delayed permit applications, meaning cities that sit on paperwork past their statutory window can have the permit automatically approved. AB 462 (2025) brought coastal ADUs under a 60-day deemed-approved clock for the first time. On the financing side, the CalHFA ADU Grant ($40,000 toward pre-development costs) closed in December 2023 after its full allocation was committed, so plan your budget without it. HCD (the Department of Housing and Community Development) publishes an updated ADU Handbook most years that is the best reference for what cities can and cannot require.
Disclaimer: Estimates on this page are based on state-level data and do not replace consultation with your local planning department, licensed contractor, or tax advisor. Verify rules and costs with local sources before starting any project.