Comprehensive 2026 guide to Accessory Dwelling Unit regulations across all 50 states.
Pioneer state for ADU legislation. Nearly 1 in 5 residential units produced is an ADU. LA leads in c...
Major reform in 2024 allowing ADUs by-right in single-family zones statewide for units under 900 sqf...
June 2025 deadline for subject jurisdictions to allow one ADU where single-unit detached dwellings a...
Seattle has seen significant ADU construction following state and local reforms. Interest rate incre...
Portland is a national leader in ADU construction. Impact fee waiver in 2010 led to major increase....
No statewide ADU preemption. Austin and some cities have local ADU ordinances but rules vary dramati...
Statewide statute 163.31771 encourages but does not mandate ADU allowances. Miami-Dade and some citi...
NYC legalized ADUs in 2024 via Local Law 126. Statewide legislation is proposed (S4547A, A4854, A677...
HB 2720 signed May 21, 2024 by Gov. Hobbs. Mandates cities 75k+ allow at least one attached AND one ...
No statewide ADU law. HB 4213 failed in January 2025. New HB 3552 proposed for 2025-2026. Chicago li...
No statewide ADU preemption. Atlanta, Decatur, and Savannah have local ADU ordinances but rules vary...
No statewide ADU law. S1106/A2792 proposed for 2024-2025 session would authorize ADUs by-right in si...
No statewide ADU law - entirely local control. Philadelphia has ADU regulations (attached or in acce...
No statewide ADU law. HB 409 (2023) passed the House but died in Senate Rules committee (April 2023)...
No statewide ADU law - entirely local control. Cincinnati was first Ohio city to legalize ADUs (Ordi...
No statewide ADU law - entirely local control. Clark Township allows ADUs in all residential distric...
No statewide ADU law - entirely local control. SB 304 passed Virginia Senate 22-18 in Feb 2024 but w...
Connecticut became the 8th state to legalize ADUs statewide via Public Act 21-29 (HB 6107) in 2021. ...
No statewide ADU law - entirely local control. Nashville pioneered with DADU ordinance in 2014 allow...
Maryland passed comprehensive statewide ADU legislation in 2025 (HB 1466/SB 891) - the Accessory Dwe...
No statewide ADU law - entirely local control. Saint Paul is a national ADU leader with progressive ...
No statewide ADU law - entirely local control. Indiana approaches ADUs through local zoning with sig...
No statewide ADU law yet but significant legislation pending. AB365 (2025) proposed by Rep. Francesc...
No statewide ADU law - entirely local control with unique incentive approach. HB 3469 (2025-2026) pr...
Strong statewide ADU law 76-2-345 MCA enacted 2023. Municipalities must allow minimum one ADU by rig...
AB 396 (2025) requires qualifying large cities to adopt ADU ordinances by Jan 1, 2026 or ADUs become...
No statewide ADU law - Alabama's lack of statewide building code means ADU regulations are entirely ...
No statewide ADU law - Louisiana operates under Home Rule meaning ADU regulations vary by Parish and...
No current statewide ADU law - entirely local control. HB 576 (2025) proposed that 'at least one acc...
Strong statewide ADU law - SF 592 signed by Governor Kim Reynolds May 1, 2025, effective July 1, 202...
No statewide ADU law - entirely local control. Topeka passed ordinance allowing ADUs in all single-f...
Moderate state law - Municipal Density and Missing Middle Housing Act (LB866) defines ADUs and appli...
Moderate statewide law H0166 (2023) effective July 1, 2023 - focuses narrowly on prohibiting restric...
No statewide ADU law - entirely local control. Salt Lake County adopted ordinance June 4, 2024 to re...
No statewide ADU law - entirely local control with limited adoption. Only some counties permit ADUs:...
No statewide ADU law - entirely local control with generally very restrictive approach. Described as...
MAJOR BREAKTHROUGH: Arkansas Act 313 (2025) creates strong statewide ADU mandate - requires every mu...
No statewide ADU law - entirely local municipal control. Oklahoma City Council approved ordinance ea...
Hawaii REVERSED from state mandate to local control - HB516 (2025) repealed previous state requireme...
No statewide ADU law - entirely local control with significant community diversity. Anchorage leads ...
Strong statewide ADU law - Vermont's 'law on equal treatment of housing and town bylaws' requires al...
EXCEPTIONALLY STRONG statewide law - LD 1829 (2025) may be strongest ADU law in nation! Requires ALL...
Strong statewide ADU law - New Hampshire Accessory Dwelling Units statute (RSA 674:71-73) became law...
Limited statewide ADU law - Rhode Island Zoning Enabling Act (§45-27-37(e)) requires localities to p...
No statewide ADU law - entirely local control. SB23 (2024) would have required local governments to ...
No statewide ADU law - entirely local control with progressive urban areas leading. St. Louis Board ...
No statewide ADU law - entirely local control with cultural acceptance of 'casitas'. Albuquerque zon...
No statewide ADU law - entirely local control with generally restrictive policies. Described as havi...
No statewide ADU law - entirely local control with some progressive local developments. Only one ADU...
No statewide ADU law - entirely local control with significant county-by-county variation. Hardy Cou...
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⚠️ Disclaimer
The information provided on this website is for general informational purposes only and does not constitute legal, financial, or professional advice. ADU laws, regulations, and requirements vary by jurisdiction and change frequently. While we strive to keep this information accurate and up-to-date, we make no representations or warranties of any kind about the completeness, accuracy, reliability, or suitability of this information. Always consult with qualified local professionals, including attorneys, architects, and your local planning department, before making any decisions regarding ADU construction or investment. Use of this information is at your own risk.
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Last updated: February 2026 | Data from state legislation and municipal codes