US ADU Legalization Map 2026
Check ADU legalization status by state and major city — legal, variance-required, or banned. The landscape is shifting fast.
Legal
9
jurisdictions
Variance
4
jurisdictions
Banned
1
jurisdictions
| State | City/Area | Status | Details |
|---|---|---|---|
| California | Statewide | Legal | By-right statewide since 2016-20; ministerial approval; SB 9 (2021) also allows a lot split and a second unit |
| Oregon | Statewide | Legal | ADUs required in cities of 2,500+ (HB 2001, 2019); Salem and others publish pre-approved ADU plans |
| Washington | Statewide | Legal | HB 1337 (2023): up to two ADUs per lot in most residential zones, owner-occupancy banned, impact fees capped at 50%. Applies to Spokane, Tacoma, Vancouver |
| Colorado | Front Range | Legal | HB24-1152 (effective June 2025): ADUs by-right in metro single-family zones — Denver, Fort Collins, Greeley, Pueblo. Currently under a home-rule legal challenge |
| Montana | Statewide | Legal | SB 528 (2023): one ADU per single-family lot, impact fees and owner-occupancy banned. Upheld by the Montana Supreme Court (2026). Covers Missoula, Billings, Bozeman |
| Massachusetts | Statewide | Legal | Affordable Homes Act: ADUs by-right in single-family zones statewide, effective February 2025 |
| Arizona | Cities 75k+ | Legal | HB 2720 (2024) requires larger cities to allow ADUs (locally "casitas") by-right; phased local adoption |
| Tennessee | Nashville | Legal | DADUs by-right in many Metro Nashville zones; owner-occupancy required |
| Texas | Austin | Legal | Legal in most Austin zones with expedited permitting; no statewide mandate |
| North Carolina | Raleigh | Variance | Permitted in many Raleigh residential districts; no statewide mandate |
| Georgia | Atlanta | Variance | Conditional-use permit required in most zones; expanding in select districts |
| Florida | Tampa | Variance | Variance / conditional use in most zones; no statewide mandate |
| Illinois | Chicago | Variance | Allowed in designated ADU zones by ordinance; pilot expanding |
| New York | New York City | Banned | Generally restricted; limited legalization pilots (e.g. "Plus One ADU") |
📍 Check your local ADU rules in detail.
ADU laws change frequently and vary by city within states. This map is a high-level snapshot. Always confirm with your local zoning authority or a land-use attorney before planning.
Data & method: Status is based on 2026 municipal code reviews and recent zoning changes. Laws change frequently — confirm with your local planning/zoning department before making decisions.
Update frequency: This map is refreshed twice yearly as new jurisdictions legalize ADUs.
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