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

Unincorporated Fremont County requires building permits for construction, reconstruction and structural modifications, with specified exemptions¹. A qualifying one-story detached accessory structure may be exempt when it is no larger than 200 square feet, non-habitable, without plumbing or electricity, and more than 3 feet from another structure¹. Fremont County has adopted building, residential, energy, mechanical and fuel-gas codes for county-administered work⁷. Agricultural buildings that meet the code definition are exempt from the adopted building codes, but still need applicable zoning placement permits⁷. An owner working on the owner's own Idaho land may be exempt from contractor registration when the owner does not intend to sell within 12 months, but that exemption does not waive building permits or inspections¹². Electrical, plumbing and HVAC work requires separate trade permits where subject to the state-administered program¹⁴.

The Fremont County Building Department administers county building-code requirements outside St. Anthony city limits¹¹. In Newdale, the city has its own building-permit requirements; Eastern Idaho Public Health remains the septic authority serving Fremont County^3,9. The county Building Department publishes the Fremont County Courthouse at 151 W 1st North in St. Anthony, phone 208-624-7200, as its contact¹¹. County Planning uses the same courthouse contact for land-use applications¹⁰. Ask Building about plans and inspections; county-administered projects receive occupancy approval after final inspection⁶. Building fees depend on square footage and construction type, with a deposit due at application submittal⁶.

Unincorporated Fremont County has zoning districts and an official zoning map governing uses and dimensional standards^2,8. Newdale enforces its own zoning; septic permitting stays with Eastern Idaho Public Health^4,5. Rural Living lists a 1-acre minimum lot, while rural tables generally require 50-foot setbacks from arterials, collectors or section-line streets, 30 feet from other roads and 25 feet from property lines not fronting a road². Coverage limits vary: rural tables require a special-use permit above 14,000 square feet, and residential tables above 25,000 square feet, alongside applicable percentage limits². Single-family buildings generally have a 30-foot height limit and accessory structures 25 feet; a special-use permit may be requested to exceed applicable limits⁶. We could not confirm a minimum dwelling size or complete accessory-dwelling rule; ask County Planning before designing on unincorporated land¹⁰.

Eastern Idaho Public Health administers onsite sewage permitting for Fremont County⁵. A septic permit is required to construct, modify or repair an individual sewage disposal system, subject to limited exceptions⁵. For a new individual septic system, the septic permit must accompany the county building-permit application⁶. The local contact is the Eastern Idaho Public Health Fremont County Office at 45 South 2nd West in St. Anthony, phone (208) 522-8065¹⁵. The tank and drainfield must be inspected before covering, and Eastern Idaho Public Health requires 48 hours' notice; a covered system must be uncovered for inspection¹⁶. Only 11.5% of county soils are rated without severe limitations for a conventional drain field, so obtain the site evaluation early¹⁷. Where community sewer is available in the Island Park/Mack's or Last Chance/Pond's service areas, the $7,458 hook-up fee must be paid before the building permit⁶.

Unincorporated Fremont County prohibits using an RV or travel trailer as a single-family dwelling². During construction of a permitted home, a temporary certificate may allow 1 RV after an approved sewage system is installed and connected; the certificate lasts no more than 180 calendar days, expires with the home permit, and requires RV removal before completed-home occupancy approval². Personal camping on your own property is excluded from the code’s campground definition, whose temporary stays are generally 15 days or less; that definition does not authorize RV dwelling use². Regulated RV parks have separate occupancy and sanitation standards². The Floodplain Overlay District separately prohibits residential use of RVs or similar trailers left in place for 180 or more consecutive days². We could not confirm tiny-home occupancy rules; ask Planning and Building how the proposed structure is classified^10,11.

1. Ask Planning to identify the zoning district, allowed use, setbacks, height and land-use approval path^2,6,8.
2. Confirm access: all new builds off county roads need a driveway permit through County Public Works, while a state-highway approach goes through the Idaho Transportation Department⁶.
3. Determine whether the named community sewer systems serve the building; otherwise obtain the Eastern Idaho Public Health septic permit before submitting the building application⁶.
4. Obtain an Idaho Department of Water Resources drilling permit and use a licensed driller for a new well¹³.
5. Submit a complete application, site plan, supporting plans and deposit to Fremont County Building for unincorporated construction; review may take approximately 4 to 6 weeks⁶. The county also publishes a separate sewer-connection sequence, with up to 14 days for supervisor review¹⁸.
6. Obtain required trade permits and complete septic and building inspections before occupancy^6,14,16.

Start with zoning and division history because Fremont County regulates short plats, standard subdivisions and land divisions². Confirm the district's lot standard and allowed use on the official zoning map before treating a listing as buildable^2,8. Development in the mapped Floodplain Overlay District requires a county permit; stream and lakeshore corridors also require Class I approval for activities such as clearing, grading, fill and accessory buildings, unless reviewed through a Class II application². Verify whether access is private, county or state maintained; a building permit does not mean the county will maintain the road to the property⁶. The effective property-tax rate is about 0.5%, and the median annual property-tax bill is about $1,360¹⁷.