ADU Laws by State: CA, AZ, UT, TX, FL and NY
A source-linked comparison of ADU rules in Apex's six focus states. The useful question is not whether a state is 'ADU-friendly.' It is which level of government controls feasibility for your parcel today.
Six-State ADU Rule Index
Legal-status review: August 26, 2026. This is educational information, not legal advice. Confirm the current ordinance and parcel conditions with the applicable planning and building departments.
| State | Statewide position | Official source |
|---|---|---|
| California | Broad statewide ministerial framework with limits on local barriers | 2026 HCD ADU Handbook |
| Arizona | HB 2720 requires covered municipalities over 75,000 to allow attached and detached ADUs, subject to statutory details | Arizona Chapter 196, HB 2720 |
| Utah | SB 284 adds detached-ADU requirements for specified municipalities in certain zones, effective October 1, 2026 | Utah SB 284 enrolled bill |
| Texas | No statewide ADU mandate; city and county rules control | 2025 SB 673 proposal, not enacted |
| Florida | No statewide mandate; section 163.31771 allows local ordinances and 2025 SB 184 died | Florida Statutes 163.31771 |
| New York | No statewide mandate; New York City has a local Ancillary Dwelling Unit framework | NYC Buildings ADU guidance |
California
California's 2026 HCD handbook describes a statewide system that generally requires ministerial handling of qualifying ADUs and limits local rules on lot size, setbacks, parking, height, and minimum allowable unit size. Local standards and site-specific limits still matter, but they operate inside the state framework.
Arizona
Arizona HB 2720 applies to municipalities with more than 75,000 residents and requires attached and detached ADU pathways on qualifying single-family lots, with statutory limits on parking, design matching, setbacks, and other barriers. Airport, tribal, easement, short-term-rental, and other statutory details require project-specific review.
Utah
Utah already regulated internal ADUs through state law. Enrolled SB 284 adds a detached-ADU requirement for specified municipalities in certain residential zones beginning October 1, 2026. Because the coverage and implementation language matter, property owners should confirm whether the city and zone are covered and which local development standards apply.
Need this drawn for your own project?
Send us the lot and what you want to build. We'll confirm which local rules apply to your parcel and come back with a firm number, at no cost.
Texas
Texas remains city-by-city. Austin, Dallas, Houston, and San Antonio do not share one statewide ADU rule. A 2025 proposal, SB 673, did not become law. Start with the parcel's city, zoning or deed restrictions, and the current local ordinance.
Florida
Florida's current statute says local governments may adopt ADU ordinances. The 2025 SB 184 proposal and 2026 SB 48 proposal both died. Our corrected Florida SB 184 guide explains the official status and why city or county rules remain controlling.
New York
New York has no statewide ADU mandate. New York City created a local Ancillary Dwelling Unit framework through City of Yes and related local laws, but that city program does not control Long Island, Albany, Buffalo, Rochester, or other municipalities.
What to Verify on Every Parcel
- Whether the parcel and primary use qualify
- Attached, detached, internal, or conversion types allowed
- Unit count, size, height, setback, lot coverage, and placement
- Parking, owner-occupancy, rental, and design restrictions
- Utility, septic, fire, flood, wildfire, and access constraints
- Permit drawings, surveys, engineering, energy, and other supporting documents
ADU Rule Index FAQ
Which Apex focus states have a statewide ADU mandate?
California has a broad statewide framework. Arizona HB 2720 applies to municipalities over 75,000. Utah SB 284 adds a detached-ADU requirement for covered municipalities beginning October 1, 2026. Texas, Florida, and New York do not have a comparable statewide rule, though New York City has its own ADU framework.
Does a state ADU law eliminate local permits?
No. State laws can limit local zoning restrictions, but building permits, site review, code compliance, utilities, and locally permitted development standards still apply.
Why is Nevada not included?
Apex is deliberately not publishing or selling Nevada drafting pages until its licensing position under Nevada law is confirmed.
Have a project like this?
Tell us what you're building and we'll scope it, confirm the timeline, and give you a firm number before any drafting starts. Every plan set is drafted to your local jurisdiction's documentation standards.
Prefer to talk it through? Call (435) 990-3556.
Turn the Rule Check Into a Buildable ADU Plan
Send the property address and intended use. Apex will start from the controlling jurisdiction and define the permit drawing scope.