Updated 2026
ADU Laws by State
ADU regulations vary dramatically by state — and often by city within a state. Select your state for a complete guide covering permit requirements, costs, setbacks, and recent law changes.
Full State Guides
California
Very PermissiveNo owner-occupancy, 4 ft setbacks, impact fees waived
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Oregon
PermissiveStatewide ADU mandate for cities 2,500+
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Washington
Permissive2 ADUs per lot required, no owner-occupancy
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Colorado
PermissiveHB 1152 mandates ADUs statewide (2024)
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Texas
ModerateCity-by-city rules; Austin is most permissive
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More States Coming Soon
How State ADU Laws Work
State law sets the minimum standard — cities can be more permissive but not more restrictive than state law allows. California, Oregon, Washington, and Colorado have among the strongest statewide ADU protections.
In states without statewide ADU preemption (like Texas), rules are entirely set at the city level — meaning ADU allowances vary dramatically from one city to the next.