ADU laws by state
Can you build an ADU in your state?
Some states require towns to allow ADUs. Most leave it to each town or county. Pick your state to see what the state requires, what your town still decides and where the rules come from.
Near Rochester or the Finger Lakes? Go straight to your town:
Check my propertyTap or click a state to open its rules.
- State law makes ADUs broadly allowed
- State law helps, with limits
- Up to each town or county
We check every state’s laws against official sources. Each page shows its sources and when we last looked. This is general information, not legal advice. Your town’s rules decide.
Every state at a glance
| State | What state law does | Last checked |
|---|---|---|
| Alabama | Up to each town or county | October 3, 2026 |
| Alaska | Up to each town or county | October 3, 2026 |
| Arizona | State law makes ADUs broadly allowed | October 3, 2026 |
| Arkansas | State law makes ADUs broadly allowed | October 3, 2026 |
| California | State law makes ADUs broadly allowed | October 3, 2026 |
| Colorado | State law helps, with limits | October 3, 2026 |
| Connecticut | State law helps, with limits | October 3, 2026 |
| Delaware | Up to each town or county | October 3, 2026 |
| District of Columbia | State law makes ADUs broadly allowed | October 3, 2026 |
| Florida | Up to each town or county | October 3, 2026 |
| Georgia | Up to each town or county | October 3, 2026 |
| Hawaii | State law helps, with limits | October 3, 2026 |
| Idaho | State law helps, with limits | October 3, 2026 |
| Illinois | Up to each town or county | October 3, 2026 |
| Indiana | Up to each town or county | October 3, 2026 |
| Iowa | State law makes ADUs broadly allowed | October 3, 2026 |
| Kansas | Up to each town or county | October 3, 2026 |
| Kentucky | Up to each town or county | October 3, 2026 |
| Louisiana | Up to each town or county | October 3, 2026 |
| Maine | State law makes ADUs broadly allowed | October 3, 2026 |
| Maryland | State law helps, with limits | October 3, 2026 |
| Massachusetts | State law makes ADUs broadly allowed | October 3, 2026 |
| Michigan | Up to each town or county | October 3, 2026 |
| Minnesota | Up to each town or county | October 3, 2026 |
| Mississippi | Up to each town or county | October 3, 2026 |
| Missouri | Up to each town or county | October 3, 2026 |
| Montana | State law makes ADUs broadly allowed | October 3, 2026 |
| Nebraska | Up to each town or county | October 3, 2026 |
| Nevada | State law helps, with limits | October 3, 2026 |
| New Hampshire | State law makes ADUs broadly allowed | October 3, 2026 |
| New Jersey | Up to each town or county | October 3, 2026 |
| New Mexico | Up to each town or county | October 3, 2026 |
| New York | Up to each town or county | October 3, 2026 |
| North Carolina | State law helps, with limits | October 3, 2026 |
| North Dakota | Up to each town or county | October 3, 2026 |
| Ohio | Up to each town or county | October 3, 2026 |
| Oklahoma | Up to each town or county | October 3, 2026 |
| Oregon | State law makes ADUs broadly allowed | October 3, 2026 |
| Pennsylvania | Up to each town or county | October 3, 2026 |
| Rhode Island | State law makes ADUs broadly allowed | October 3, 2026 |
| South Carolina | Up to each town or county | October 3, 2026 |
| South Dakota | Up to each town or county | October 3, 2026 |
| Tennessee | Up to each town or county | October 3, 2026 |
| Texas | Up to each town or county | October 3, 2026 |
| Utah | State law makes ADUs broadly allowed | October 3, 2026 |
| Vermont | State law makes ADUs broadly allowed | October 3, 2026 |
| Virginia | State law helps, with limits | October 3, 2026 |
| Washington | State law makes ADUs broadly allowed | October 3, 2026 |
| West Virginia | State law helps, with limits | October 3, 2026 |
| Wisconsin | Up to each town or county | October 3, 2026 |
| Wyoming | Up to each town or county | October 3, 2026 |
State law is only half the answer
Even in states with strong ADU laws, your town still sets things like setbacks, height and design rules. In states without a statewide law, like New York, the town decides almost everything. Our guide shows how to check your town’s rules and get an answer in writing.