Idaho HB 706 — Single-Stair Building Option (City Opt-In) (ID)
Tracked preemption from the Idaho overlay bundle.
Overview
← All state preemptionsIdaho overlay roll-upIdaho zoning wikiIdaho building codesFederal overlaysGlossaryFederal-conflict: Yes
Effective
2026-07-01
Sunset
—
Authority
state
Scope
state:ID
Other Idaho preemptions
Idaho SB 1354 — ADU By-Right (Cities ≥10,000)Idaho SB 1352 — Starter-Home Subdivisions (Cities ≥10,000)Idaho HB 707 — Administrative Lot Splits (Cities ≥10,000)Idaho HB 585 — Permit Inspection Shot-Clock (Statewide)Idaho Dillon's Rule — Inclusionary Zoning Mandates Ultra Vires (Mountain Central v. McCall, 2021)Idaho §67-6539 — Short-Term Rental Preemption (HB 216, 2017; HB 583, 2026)Idaho §67-6509A — Manufactured Housing Parity (extended by HB 800, 2026)Idaho Development Impact Fee Act (I.C. §67-8201 et seq.)
Primary-source summary
HB 706 — Single-stair optionTrigger predicate
When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.
city.single_stair_option_adopted == TruePreempted fields
4 fields on the base district schema are rewritten when the trigger fires.
| Field | Op | Value | Note |
|---|---|---|---|
base_districts[category=res_mf].single_stair_buildings_allowed | override | True | Up to 4 dwellings per floor, 4–6 stories |
base_districts[category=res_mf].max_dwellings_per_floor_single_stair | cap_at | 4 | |
base_districts[category=res_mf].max_stories_single_stair | cap_at | 6 | |
single_stair_life_safety_requirements | override | ['automatic_sprinklers', '2_hour_pressurized_stairs', 'fire_rated_corridors'] |
Citation
Authority source
Idaho HB 706 (2026)
§ 2026 Idaho Session Laws — HB 706
Research notes
Permissive (opt-in) building-code preemption — cities must affirmatively adopt the option for it to apply locally. Enhanced life-safety requirements (sprinklers, 2-hour pressurized stairs, fire-rated corridors) are mandatory when option is exercised.