Idaho — Code Adoption Summary
Adoption model: Statewide-mandatory floor (Idaho Building Code Board, 3-year legislative adoption cycle); locals may add more-restrictive amendments.
Last verified: 2026-07-03
Confidence: verified
Primary sources: ID Div. of Occupational & Professional Licenses — https://dbs.idaho.gov · ICC ID
Statewide adopted codes — current (2026)
| Code family | Adopted edition | Notes | Source |
|---|
| Building / Residential | 2018 I-Codes base (per 2024-era state reference) | | meltplan.com |
| Electrical (NEC) | NEC 2020 | | up.codes/idaho |
| Plumbing | 2017 Idaho State Plumbing Code = UPC-based | Idaho = UPC (not IPC) | up.codes/idaho |
| Energy | IECC 2018 | | " |
Adoption model & precedence
- Codes are statewide; updated every 3 years by the Idaho Legislature as ICC revises, with amendments set by the Idaho Building Code Board.
- Local jurisdictions (cities/counties) may add their own amendments, generally more restrictive than the state baseline.
- AHJ = local building department, applying the statewide code + any local amendments.
Major cities / counties
| Jurisdiction | County | Notes | Building dept. |
|---|
| Boise | Ada | statewide code + local amendments — publishes current-codes page | cityofboise.org |
| Meridian | Ada | statewide code + possible local amendments | meridiancity.org |
| Nampa | Canyon | statewide code + possible local amendments | cityofnampa.us |
AHJ fallback (when local adoption is unverified)
- State baseline (certain): 2018 I-Codes base, NEC 2020, 2017 Idaho Plumbing Code (UPC-based), IECC 2018.
- Action: confirm any city/county-specific amendments, especially in Boise.
Change log
- 2026-07-03 — created; verified NEC 2020, UPC-based 2017 Idaho Plumbing Code, IECC 2018, 3-year legislative adoption cycle.
