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Zoning & Legal · 2026

ADU Laws by State —
What the Law Says
Where You Live.

A sourced directory for all 50 states plus Washington, DC—separating operative frameworks, implementation transitions, future-effective laws, and locally controlled jurisdictions without treating classification as project approval.

51State + DC jurisdictions
17Effective frameworks
4Transition / future
30Local-control entries
On This Page
The Regulatory Landscape

How ADU Law Is Classified

ADU regulation operates through state or district law, local zoning and building rules, and—where applicable—private covenants. The controlling question is not simply whether a state “allows ADUs,” but which layer establishes the operative rule for the particular jurisdiction and parcel.

State framework

Operative framework

State or district law establishes an ADU framework. Coverage, exceptions, and local administration still matter.

In transition

Implementation underway

The law is enacted, but a local compliance deadline or implementation period remains open.

Future effective

Not operative yet

The law has passed but its effective date has not arrived. Existing local rules continue to govern.

Local control

City or county rules

No broad statewide siting mandate was identified. Local rules may be permissive, restrictive, or unavailable.

Classification is not a project approval. It does not rank states, guarantee that a parcel qualifies, or replace the local ordinance. It identifies the governing legal posture as a starting point for project research.
50 States + Washington, DC

State-by-State ADU Law Directory

Search any jurisdiction to see its current classification, controlling framework or local-control status, scope summary, state planning guide, and official source where an enacted framework is identified.

Showing all 51 jurisdictions.

Alabama

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Alaska

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Arizona

State framework
HB 2720 (2024) + HB 2928 (2025)

Cities above the statutory population threshold and counties operate under state ADU standards; local permits and development rules still apply.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Arkansas

State framework
Act 313 of 2025

Cities and incorporated towns must allow at least one ADU on qualifying single-family lots, subject to the act and local code.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

California

State framework
Government Code §§ 66310–66342

State law establishes broad ADU approval standards and review protections; local zoning, building, utility, fire, and site rules still apply.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Colorado

State framework
HB 24-1152

Covered “subject jurisdictions” must provide an administrative ADU approval path. The law does not apply identically to every Colorado locality.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Connecticut

State framework
Public Act 21-29 / Conn. Gen. Stat. ch. 124

State law created an as-of-right ADU framework, but municipalities could follow statutory opt-out procedures; verify the current local ordinance.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Delaware

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Florida

Local control
Local rules control

Florida Statutes § 163.31771 authorizes local ADU ordinances but does not require every local government to adopt one. SB 184 (2025) died and did not create a statewide mandate.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Georgia

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Hawaii

In transition
Act 39 of 2024

Counties must implement the state housing framework by December 31, 2026; exceptions and county permitting rules remain important.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Idaho

In transition
SB 1354 (2026)

Effective July 1, 2026 for covered cities; cities above 10,000 residents have an implementation deadline of February 1, 2027.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Illinois

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Indiana

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Iowa

State framework
Iowa Code §§ 364.3 and 331.301

State law limits city and county restrictions on at least one ADU on qualifying single-family lots; local permits and safety codes remain.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Kansas

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Kentucky

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Louisiana

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Maine

State framework
30-A M.R.S. § 4364-B

State housing law requires ADU allowance in covered residential areas, subject to current statute and municipal administration.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Maryland

In transition
HB 1466 / Chapter 197 (2025)

Covered localities must adopt compliant ADU ordinances by October 1, 2026; local rules remain the operative checkpoint during implementation.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Massachusetts

State framework
Affordable Homes Act (2024)

One ADU is protected by right in single-family residential zoning under the state framework, subject to building and site requirements.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Michigan

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Minnesota

Local control
Local rules control

No broad statewide ADU siting mandate was identified. Local ordinances—including Minneapolis and other city rules—control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Mississippi

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Missouri

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Montana

State framework
Mont. Code Ann. § 76-2-345

State law requires covered local governments to allow ADUs under statutory standards; confirm current local administration and site rules.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Nebraska

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Nevada

State framework
AB 396 / Chapter 365 (2025)

The state framework applies to specified higher-population jurisdictions and includes exceptions; it is not a universal parcel-level guarantee.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

New Hampshire

State framework
RSA 674:71–:73

State law requires local ADU accommodation under the current statutory framework; configuration and local approval details still vary.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

New Jersey

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

New Mexico

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

New York

Local control
Local rules control

No broad statewide ADU siting mandate was identified. Local zoning and building rules control; state tax or housing programs do not themselves establish parcel eligibility.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

North Carolina

Local control
Local rules control

No broad statewide ADU siting mandate was identified. Proposed legislation should not be treated as enacted law; city and county rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

North Dakota

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Ohio

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Oklahoma

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Oregon

State framework
ORS 197A.425

Covered cities and urban county areas must allow ADUs under state housing law; local siting, building, and permit rules still apply.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Pennsylvania

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Rhode Island

State framework
R.I. Gen. Laws § 45-24-73

State law establishes ADU rights and standards, while local building review and property-specific conditions remain.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

South Carolina

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

South Dakota

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Tennessee

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Texas

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Utah

State framework
Utah Code § 10-9a-530

State law primarily protects internal ADUs in covered areas; it should not be read as a universal detached-ADU mandate.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Vermont

State framework
Act 47 (2023)

The HOME Act strengthened statewide ADU allowance, subject to municipal administration, building rules, and site constraints.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Virginia

Future effective
SB 531 (2026)

Enacted statewide ADU requirements take effect July 1, 2027. Current local ordinances control until then.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Washington

State framework
HB 1337 / RCW 36.70A.681

Covered Growth Management Act jurisdictions must implement state ADU standards on qualifying lots, with statutory exceptions and local permitting.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

Washington, DC

State framework
DC Zoning Regulations

Accessory apartments are governed by District zoning and building rules rather than a state statute; eligibility varies by zone and property.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guideOfficial source

West Virginia

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Wisconsin

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Wyoming

Local control
Local rules control

No broad statewide ADU siting mandate was identified in this review. City, county, zoning, building, utility, and site rules control.

Project rule: Verify the current local ordinance and parcel conditions before relying on this classification.
State planning guide

Legal-source review date: August 5, 2026. “No broad statewide mandate identified” is a research classification, not proof that no relevant state provision exists. Laws and local ordinances change; verify current requirements with the responsible agencies.

Rules Explained

Legal Terms That Affect ADU Feasibility

By Right / Ministerial
Approval under objective standards without a discretionary land-use hearing. Building, fire, utility, and site approvals may still be required.
Owner Occupancy
A requirement that the owner reside in the primary dwelling or ADU. Current state and local law determine whether it may be imposed.
Covered Jurisdiction
A city, county, or area to which a state framework applies. Population, planning-law, or geographic thresholds may exclude other jurisdictions.
Setback
Required distance from property lines, streets, structures, easements, or hazards. The applicable number is parcel- and ordinance-specific.
Parking Standard
A requirement for off-street parking. State frameworks may restrict local parking mandates in specified circumstances.
Impact or Connection Fee
A charge associated with development or utility service. Applicability and exemptions vary by jurisdiction, ADU size, and utility arrangement.
Deed Restriction
A recorded restriction that can govern occupancy, affordability, rentals, or other property use and may bind future owners.
Private Covenant / HOA Rule
A private property restriction distinct from zoning. Its enforceability depends on governing documents and current state law.
Private Restrictions

HOAs, CC&Rs and ADU Approval

Zoning permission and private covenant compliance are separate questions. An HOA declaration, CC&Rs, architectural rules, or rental restrictions may affect a project unless applicable state law limits their enforcement.

California provides a specific statutory protection in Civil Code § 4751. Outside any clearly verified statutory protection, do not assume that zoning approval overrides private covenants.

Before paying for design: Obtain the complete governing documents, identify architectural-review and rental provisions, check current state law, and seek qualified legal advice when the language or enforceability is uncertain.
Project Verification

How to Verify the Rule for Your Property

  1. Identify the legal parcel and zoning district.Use the assessor record and current official zoning map.
  2. Check the directory classification and source.Determine whether an operative, transition, future, or local-control framework applies.
  3. Read the current local ordinance.Confirm ADU type, size, setbacks, parking, occupancy, access, and approval procedure.
  4. Check overlays and other agencies.Historic, coastal, environmental, fire, health, septic, utility, and flood rules may add requirements.
  5. Request written local confirmation.Ask planning or zoning staff to confirm the current rule before final design or construction.
FAQ

Frequently Asked Questions

What do the four classifications mean?
State Framework means an operative state or district framework applies. In Transition means an enacted framework is still within an implementation period. Future Effective means an enacted law is not yet operative. Local Control means no broad statewide ADU siting mandate was identified and local rules control.
Does “State Framework” mean my ADU is automatically allowed?
No. A state framework may limit local restrictions or establish an approval path, but parcel eligibility can still depend on statutory coverage, zoning, setbacks, utilities, fire access, environmental overlays, building codes, and other local requirements.
Does “Local Control” mean ADUs are prohibited?
No. It means the controlling rules are established locally rather than through a broad statewide siting mandate. One city may allow ADUs by right while another jurisdiction in the same state may impose different requirements.
What is an owner-occupancy requirement?
It is a rule requiring the owner to live in either the primary dwelling or the ADU. Whether such a requirement is allowed, prohibited, or limited depends on current state law, local implementation, property type, and sometimes ADU configuration.
Can an HOA restrict an ADU?
HOA authority varies by state and by the governing documents. Zoning permission does not automatically eliminate private covenants. Review the current state law and the HOA declaration or CC&Rs before investing in design.
How do I confirm whether an ADU is allowed on my lot?
Identify the parcel and zoning district, check the current state framework and local ordinance, review overlays and utilities, and obtain written confirmation from the local planning or zoning department before final design or construction.
Legal disclaimer: This guide is educational planning information, not legal advice. The classifications were reviewed August 5, 2026. Statutes, regulations, ordinances, agency interpretations, and private restrictions can change. Verify the current rule with the responsible agencies and qualified professionals before making a construction or property decision.

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