Building permits, zoning and land rules in Jerome County, Idaho

Unincorporated Jerome County requires a building permit before covered construction begins: remodels, additions, structures over 200 square feet, structures with electricity or plumbing, and permanently affixed structures are covered¹. Qualifying one-story detached accessory structures no greater than 200 square feet can be exempt from building permits, but small size alone does not waive zoning approval or permit triggers such as attachment and utilities^1,2. Jerome County administers adopted residential codes, including the 2018 International Residential Code with amendments¹⁰. Electrical, plumbing and HVAC work requires trade permits, although the administering jurisdiction varies by location¹¹. An owner working on the owner’s own Idaho land can be exempt from contractor registration if the owner does not intend to sell within 12 months; applicable permits and inspections still apply^7,8. Non-exempt structures require certificate-of-occupancy approval and a separate certificate of compliance before use or occupancy².

The Jerome County Building Department handles inspection, plan review and investigative services in unincorporated Jerome County¹². Its office is at 300 N Lincoln, Room 200, Jerome, ID 83338, and the main phone is 208-324-9262¹². Planning & Zoning shares that room and can be reached at 208-324-9116 or planning&zoning@co.jerome.id.us¹³. Start with an Information Request so Planning & Zoning can confirm that the project is allowed on the parcel; zoning approval must come before building-permit review^2,13. An application inactive for 90 days after notice of missing information may be returned without refund; construction must begin within 180 days unless extended in writing². Zoning applications require a nonrefundable fee set by the Board, but the current amount was not confirmed².

Jerome County zones unincorporated land and controls zoning activities in city impact areas, where cities retain advisory rights and additional impact-area rules apply⁵. Incorporated-city regulations may differ from the county rules described here⁵. Septic permits remain with South Central Public Health District, which serves Jerome County^3,4. The official zoning map includes agricultural, rural-residential, airport, commercial, industrial, city-impact and recreation districts with differing standards⁵. We could not confirm exact setback distances or minimum dwelling sizes; ask Planning & Zoning for the parcel’s district standards. Before work begins on a structure with approved zoning, the county requires a setback pre-inspection². Land divisions and preliminary or final plats require an appointment with Planning & Zoning¹³. Regulated floodplain development requires a floodplain-development permit administered by the Floodplain Ordinance Administrator, after zoning approval².

South Central Public Health District reviews applications and issues permits for new and repaired septic systems in Jerome County^3,4. The district's Jerome office is at 951 East Avenue H, Jerome, ID 83338; call (208) 324-8838 or email septic@phd5.id.gov¹⁴. Septic permits were not required before 1971, so an older system may have no permit record⁴. Only 8.9% of Jerome County soils are rated without severe limitations for a conventional drain field, so make septic feasibility an early purchase contingency¹⁵. Permit applications must describe proposed water and sewer service and include applicable water, septic, sewer or health-authority approvals; the county materials do not impose universal public-utility connection². Ask the district what site evaluation and inspections the particular system will require.

We could not confirm a countywide allowance for long-term RV occupancy, private-land camping or tiny-home occupancy in unincorporated Jerome County. Ask Planning & Zoning about the parcel, duration, utility connections and zoning district before placing or occupying an RV or tiny home. Jerome County's published definitions address mobile homes but do not expressly define tiny homes, and a non-exempt structure cannot be used or occupied until the Administrator or Building Official approves a certificate of occupancy². A tiny structure is not automatically permit-free: a residential structure needs a permit when it exceeds 200 square feet, has electricity or plumbing, or is permanently affixed⁶. District rules may control building size, height, lot coverage, yards and use⁵. Manufactured homes must be inspected and approved by the authority having jurisdiction before occupancy¹⁶.

1. Send Planning & Zoning an Information Request to confirm the use and district, then obtain zoning approval before building-permit review^2,13.

1. Prepare the site plan, property and structure details, water and sewer documentation, and any required access, fire, irrigation, health and easement approvals².

1. Check flood status; zoning approval must precede review of a required floodplain-development permit².

1. Establish septic feasibility and obtain the South Central Public Health District permit; if using a well, obtain an IDWR drilling permit before a licensed driller starts^4,9.

1. Include the responsible agency’s access permit with the zoning application for new access onto a federal, state or highway-district public street; projects over 150 feet from the main road need a fire-department letter and an approved access road installed before construction².

1. Complete the county's setback pre-inspection, then apply for building and applicable trade permits^2,6,11.

1. Obtain certificate-of-occupancy approval and a certificate of compliance before using a non-exempt structure².

Locate the parcel on the official zoning map and have Planning & Zoning confirm its district, allowed use, setbacks and other dimensional standards^2,5. If the parcel is being divided, budget time for the applicable plat or land-division process and an appointment with Planning & Zoning¹³. Verify septic feasibility before the purchase becomes final: only 8.9% of county soils are rated without severe limits for a conventional drain field¹⁵. Jerome County averages about 10 inches of precipitation annually, and severe drought occurred in 14.9% of years, so document the water source and any water rights¹⁵. A new well requires an IDWR drilling permit and licensed driller⁹. Confirm legal road access and any agency permit for a new public-street approach². Screen for floodplain permitting and budget around an effective property-tax rate of about 0.6% and a median annual bill of $1,623^2,15.