ALLocal rules control
Alabama
ADUs are possible in parts of Alabama, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
Back to ZoningTrace Nationwide ADU law directory
Fifty states. No fifty-state shortcut.
Start with the statewide posture, then trace the local ordinance, lot limits, utilities, overlays, and permit path that decide the actual property.
50 statesEvery state has a dated guide
20 active frameworksIncluding limited and opt-out laws
2 additional areasDC and Guam verified
Find the controlling starting point.
“Statewide” can still mean population thresholds, urban-growth boundaries, municipal opt-outs, or a future implementation date. Each guide keeps those distinctions visible.
52 guides
AKLocal rules control
Alaska
ADUs are possible in parts of Alaska, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
AZState protections in covered jurisdictions
Arizona
Arizona gives many homeowners a strong path to a casita or ADU, but the controlling state rule depends on whether the parcel is in a covered city, town, or county.
Free state guideOpen guide
ARStatewide municipal right
Arkansas
Arkansas municipalities must provide a by-right route for at least one qualifying ADU, while building, water, sewer, health, and site rules continue to apply.
Free state guideOpen guide
CAStrong statewide right
California
California provides one of the country's strongest ADU frameworks, but unit count, configuration, fire access, utilities, coastal review, and local objective standards still change the property-specific result.
Free state guideOpen guide
COBy-right in covered jurisdictions
Colorado
Colorado protects one ADU as an accessory use in covered urban jurisdictions, but rural areas and excluded jurisdictions may remain under different local rules.
Free state guideOpen guide
CTState baseline with municipal opt-outs
Connecticut
Connecticut's statute creates a useful ADU baseline, but the first property question is whether the municipality retained it, opted out, or adopted a different local ordinance.
Free state guideOpen guide
DELocal rules control
Delaware
ADUs are possible in parts of Delaware, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
FLLocal rules control
Florida
ADUs are possible in parts of Florida, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
GALocal rules control
Georgia
ADUs are possible in parts of Georgia, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
HICounty implementation required
Hawaii
Hawaii directs the counties to permit qualifying ADUs, but island-specific zoning, water, wastewater, shoreline, hazard, and infrastructure rules remain decisive.
Free state guideOpen guide
IDLaw effective; local codes due
Idaho
Idaho's new law creates an ADU right in covered cities, but local code updates are still underway and smaller jurisdictions may follow different rules.
Free state guideOpen guide
ILLocal rules control
Illinois
ADUs are possible in parts of Illinois, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
INLocal rules control
Indiana
ADUs are possible in parts of Indiana, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
IAStatewide city and county right
Iowa
Iowa requires cities and counties to allow at least one ADU, while statewide building requirements and local health, site, and infrastructure rules remain.
Free state guideOpen guide
KSLocal rules control
Kansas
ADUs are possible in parts of Kansas, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
KYLocal rules control
Kentucky
ADUs are possible in parts of Kentucky, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
LALocal rules control
Louisiana
ADUs are possible in parts of Louisiana, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
MEStatewide baseline
Maine
Maine provides a statewide ADU baseline, but shoreland zoning, subsurface wastewater, lot dimensions, water supply, and municipal implementation remain central.
Free state guideOpen guide
MDLocal laws due October 2026
Maryland
Maryland has adopted a statewide implementation mandate, but on August 6, 2026 each property still requires a check of the jurisdiction's current or newly adopted ordinance.
Free state guideOpen guide
MAProtected use statewide outside Boston
Massachusetts
Massachusetts protects one qualifying ADU by right outside Boston; local dimensional review, Title 5 or sewer, building code, wetlands, flood, and historic rules still apply.
Property briefs liveOpen guide
MILocal rules control
Michigan
ADUs are possible in parts of Michigan, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
MNLocal rules control
Minnesota
ADUs are possible in parts of Minnesota, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
MSLocal rules control
Mississippi
ADUs are possible in parts of Mississippi, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
MOLocal rules control
Missouri
ADUs are possible in parts of Missouri, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
MTStrong statewide right
Montana
Montana broadly protects ADUs, but local objective standards, sanitation, water, wildfire exposure, access, and private restrictions still shape feasibility.
Free state guideOpen guide
NELocal rules control
Nebraska
ADUs are possible in parts of Nebraska, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
NVCovered larger cities and counties
Nevada
Nevada now requires covered larger jurisdictions to authorize ADUs, but population thresholds and the regional-planning exception mean the rule is not uniform statewide.
Free state guideOpen guide
NHStatewide right
New Hampshire
New Hampshire protects one attached or detached ADU by right, while state septic requirements and defined local health and safety controls remain.
Free state guideOpen guide
NJLocal rules control
New Jersey
ADUs are possible in parts of New Jersey, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
NMLocal rules control
New Mexico
ADUs are possible in parts of New Mexico, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
NYLocal rules control
New York
ADUs are possible in parts of New York, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
NCLocal rules control
North Carolina
ADUs are possible in parts of North Carolina, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
NDLocal rules control
North Dakota
ADUs are possible in parts of North Dakota, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
OHLocal rules control
Ohio
ADUs are possible in parts of Ohio, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
OKLocal rules control
Oklahoma
ADUs are possible in parts of Oklahoma, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
ORCities and urban growth areas
Oregon
Oregon has a mature ADU framework in covered urban areas, but city standards, system-development charges, utilities, wildfire, and unincorporated rural rules vary substantially.
Free state guideOpen guide
PALocal rules control
Pennsylvania
ADUs are possible in parts of Pennsylvania, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
RIBroad statewide by-right protection
Rhode Island
Rhode Island broadly protects one ADU, but the path depends on the existing structure, lot size, utilities, flood/coastal constraints, and the statute's qualifying circumstances.
Free state guideOpen guide
SCLocal rules control
South Carolina
ADUs are possible in parts of South Carolina, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
SDLocal rules control
South Dakota
ADUs are possible in parts of South Dakota, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
TNLocal rules control
Tennessee
ADUs are possible in parts of Tennessee, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
TXLocal rules control
Texas
ADUs are possible in parts of Texas, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
UTState protections with jurisdiction thresholds
Utah
Utah's rules distinguish internal and detached ADUs and apply through defined municipal categories and lot thresholds, so the exact property and local code matter.
Free state guideOpen guide
VTStatewide baseline
Vermont
Vermont requires a path for one qualifying ADU, but wastewater permits, water supply, flood hazard, village design, access, and local dimensional rules remain central.
Free state guideOpen guide
VAEnacted; effective July 2027
Virginia
Virginia has enacted a statewide ADU right, but it does not take effect until July 1, 2027; current local ordinances control until then.
Free state guideOpen guide
WAStrong urban-area right
Washington
Washington provides strong ADU rights in covered urban areas, often allowing two units, but critical areas, utilities, lot configuration, and local objective standards remain.
Free state guideOpen guide
WVStatewide municipal right
West Virginia
West Virginia municipalities must allow at least one attached, detached, or internal ADU by right, while safety, utilities, flood, access, and objective site standards continue to apply.
Free state guideOpen guide
WILocal rules control
Wisconsin
ADUs are possible in parts of Wisconsin, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
WYLocal rules control
Wyoming
ADUs are possible in parts of Wyoming, but there is no single statewide yes. The municipality, zoning district, unit type, and site constraints determine the path.
Free state guideOpen guide
DCDistrict-wide zoning right
District of Columbia
Washington, DC allows one accessory apartment as a matter of right in most R zones, but the principal-house size, zone, unit location, lot occupancy, alley access, and building permits still matter.
Free state guideOpen guide
GUTerritory-wide zoning provisions
Guam
Guam expressly provides for attached and detached ADUs in qualifying R1, R2, and A zones, but lot area, sewer proximity, groundwater protection, setbacks, utilities, and environmental rules can control the outcome.
Free state guideOpen guide