State Preemption of Local Zoning in New Hampshire

What Is State Preemption?

State preemption occurs when a state law overrides local government ordinances in a specific area. In land use, preemption means a city or county cannot adopt zoning rules that are more restrictive than the state standard. If a city tries to prohibit something the state law permits, the state law wins.

New Hampshire actively uses preemption in housing law. The state has enacted legislation that prohibits local governments from blocking certain types of housing development — most notably accessory dwelling units (ADUs) and lot splits.

ADU Preemption

What local governments cannot restrict:

• ✓Local regulations may set reasonable dimensional standards but may not effectively prohibit ADUs · Source
• ✓Municipalities may require a conditional use permit but cannot require a variance or special exception for compliant ADU proposals · Source