State Preemption of Local Zoning in Hawaii
How Hawaii state law overrides local zoning ordinances. ADU preemption, lot split preemption, and impact on city-level regulations.
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.
Hawaii 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
Hawaii Act 232 (2023) — Relating to Accessory Dwelling Units
This law preempts local ordinances — cities cannot impose rules stricter than the state ADU standard. Effective 2023-07-06.
What local governments cannot restrict:
- ADUs must receive ministerial approval — no special permit, conditional use permit, or variance required
- Counties may establish reasonable design and dimensional standards but cannot effectively prohibit ADUs
How Preemption Affects Hawaii Cities
State preemption applies to every incorporated city and unincorporated area in Hawaii. Select a city below to see how state preemption interacts with local zoning rules.
Source: Hawaii Act 232 (2023) — Relating to Accessory Dwelling Units. Last verified April 5, 2026. View source