What States Allow ADUs? Statewide ADU Laws (2026)

ADUs are legal in all 50 states — the real question is whether your state forces local governments to allow them. As of 2026, at least 11 states have passed statewide laws requiring cities to permit ADUs by-right or ministerially (led by California, Oregon, Washington, and most of New England). In the remaining states, local zoning decides — so whether you can build depends on your specific city or county. The table below shows where each state stands; click a state for city-by-city rules.

Which States Allow ADUs — Statewide Law Table (2026)

State	Statewide ADU Law?	Key Statute	What It Does
California	Yes — statewide mandate	Gov. Code §§66310-66342	Up to 1,200 sq ft detached; 4 ft setbacks; no parking near transit; no owner-occupancy; 60-day ministerial approval
Oregon	Yes — statewide mandate	HB 2001 / ORS 197.312	ADUs required in single-family zones of larger cities; no off-street parking mandate
Washington	Yes — statewide mandate	HB 1337 (2023)	Cities must allow up to 2 ADUs per lot; no owner-occupancy mandate; parking can't be required within ½ mile of major transit (otherwise limited to 1-2 spaces by lot size)
Maine	Yes — statewide mandate	LD 2003 (2022)	At least 1 ADU allowed by-right on single-family lots statewide
Vermont	Yes — statewide mandate	Act 47 / 24 V.S.A. §4412	1 ADU allowed by-right with single-family home statewide
New Hampshire	Yes — statewide mandate	RSA 674:71-73	1 attached ADU allowed by-right in any single-family zone
Massachusetts	Yes — statewide mandate	Affordable Homes Act §8 (2024)	ADUs by-right in single-family zones in all 351 municipalities (effective 2025)
Connecticut	Partial — opt-out	PA 21-29	ADUs allowed by-right statewide unless a town formally opts out
Rhode Island	Yes — statewide mandate	RIGL §45-24-37 (2024)	1 ADU allowed by-right on owner-occupied single-family lots
Montana	Yes — statewide mandate	SB 528 (2023)	ADUs required by-right in larger cities' single-family zones
Utah	Partial — internal ADUs	HB 82 (2021)	Internal ADUs allowed in most single-family zones; detached up to local rules
Arizona	Yes (large cities)	HB 2720 (2024)	Cities over 75,000 must allow ADUs by-right in single-family zones
Colorado	Yes (large cities)	HB 24-1152	Larger cities must allow at least 1 ADU in single-family zones
Nevada	Reform underway	AB 396 (2025)	Large cities/counties must adopt ADU ordinances by July 1, 2026
Hawaii	Partial — county-led	Act 39 / county codes	ADUs ('ohana units') allowed via county ordinances; Honolulu by-right on many lots
Texas	No statewide law — local control	Local zoning	Each city decides; Austin permissive, Fort Worth allows accessory-only ADUs under §5.301
Florida	No statewide mandate — local control	Live Local Act; SB 48 failed 2026	Local rules govern; SB 48 statewide mandate died in the House in 2026
New York	Local control (NYC pilot)	Local zoning; NYC City of Yes	No statewide mandate; NYC expanded ADU eligibility via City of Yes (2024)
Illinois	Local control	Local zoning	Decided by city; Chicago expanded its ADU program citywide
Georgia	Local control	Local zoning	Decided by city; Atlanta and Savannah allow ADUs in many residential zones
North Carolina	Local control	Local zoning	Decided by city; Durham, Raleigh, and Charlotte permit ADUs locally
Minnesota	Local control	Local zoning	Decided by city; Minneapolis and St. Paul allow ADUs citywide
Pennsylvania	Local control	Local zoning	Decided by city; Pittsburgh permits ADUs in residential districts

"Statewide mandate" means the state requires local governments to allow ADUs; "local control" means each city or county sets its own rules. Laws change frequently — verify with your local planning department.