ADU Laws in Idaho (2026)
Idaho state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.
Law Name
State ADU Law
Preempts Local Ordinances
No — local rules may be stricter
Has State Law
Yes
Key Provisions
Idaho does not have a statewide ADU preemption law as of 2026
ADU regulation is left entirely to local municipalities under Idaho Code Title 67 (local government)
Boise has adopted permissive local ADU allowances through City Code Title 11
Idaho's legislature has debated housing reform measures related to ADUs and density but no comprehensive preemption has passed
Idaho's strong home rule tradition means municipalities retain zoning authority
Some Idaho municipalities have adopted ADU-permissive zoning following Boise's example
Official Sources
Source: Idaho State ADU Law. Last verified April 5, 2026. View source