ADU Rules in Idaho (2026)
ADU rules in Idaho — no statewide ADU law. Regulation is entirely local. Key provisions and city-specific frameworks for accessory dwelling units.
Law Name
Preempts Local Ordinances
No — local rules may be stricter
Has State Law
No — regulation is local
Statewide Preemption Status Unconfirmed
No statewide preemption statute was confirmed for this jurisdiction — regulation is local. Local governments retain full authority to set their own rules.
Local Control Framework
Idaho does not have a statewide ADU preemption law as of 2026 · Source
ADU regulation is left entirely to local municipalities under Idaho Code Title 67 (local government) · Source
Boise has adopted permissive local ADU allowances through City Code Title 11 · Source
Idaho's legislature has debated housing reform measures related to ADUs and density but no comprehensive preemption has passed · Source
Idaho's strong home rule tradition means municipalities retain zoning authority · Source
Some Idaho municipalities have adopted ADU-permissive zoning following Boise's example · Source
Source: Idaho Local Zoning Authority. Last verified April 5, 2026. View source