Unincorporated Jefferson County building permits
VerifiedDepartment contacts, adopted codes, permit types, fees, and gotchas for Unincorporated Jefferson County, Idaho.
Last verified 2026-07-08 · Source · Embed this page’s badge · Version history
Building department
- Address
- 210 Courthouse Way, Suite 170, Rigby, ID 83442
- Phone
- 208-745-9220
- Office hours
- Mon–Fri 9:00 AM – 5:00 PM
- Website
- Official site
Inspection guide
See how inspections work in Unincorporated Jefferson County — sequence, scheduling & re-inspection fees.
Codes adopted
Idaho adopts a statewide baseline building code set under the Idaho Building Code Act (Idaho Code Title 39, Chapter 41) and IDAPA rules administered by the Idaho Division of Occupational and Professional Licenses (DOPL). Effective January 1, 2021, the statewide baseline includes the 2018 International Building Code (IBC), 2020 Idaho Residential Code (based on the 2018 IRC Parts I–III and IX with Idaho amendments), 2020 Idaho Energy Conservation Code (based on the 2018 IECC with Idaho amendments), 2018 International Existing Building Code (IEBC), 2018 International Mechanical Code (IMC), 2018 International Fuel Gas Code (IFGC), and 2018 International Fire Code (IFC). The National Electrical Code is adopted separately by the Idaho Electrical Board (IDAPA 24.39.10), not bundled with the building code: Idaho enforces the 2023 NEC, effective July 1, 2024 (the state used the 2017 NEC with amendments before that and skipped the 2020 edition). Local jurisdictions must enforce the state baseline and may adopt amendments only where those amendments are at least as stringent as the state-adopted editions; local amendments may not be less restrictive. Enforcement is local — each city or county issues permits and performs inspections. Always confirm the current adopted edition and any local amendments with your specific jurisdiction before submitting plans.
- 2018 International Building Code (IBC) — adopted by Jefferson County Ordinance 2022-02, effective March 7, 2022
- 2018 International Residential Code (IRC) — adopted by Jefferson County Ordinance 2022-02, effective March 7, 2022
Permit types & fees
Residential Building Permit (Single-Family Dwelling / New Construction, Additions, ADUs)
Required for new single-family dwellings, additions, accessory dwelling units, remodels, and most accessory structures over 120 sq ft in unincorporated Jefferson County. Governed by the 2018 IRC as adopted by Ordinance 2022-02. Applications are submitted through the Jefferson County Planning, Zoning & Building Cityworks public portal; mechanical, electrical, and plumbing trade permits/inspections are handled separately by the Idaho Division of Occupational and Professional Licenses (DOPL), not the county.
Solar Permit
Unlike some other Idaho counties in this corpus, Jefferson County issues its own distinct county-level 'Solar Permit' (internal Permit Type code BP-SOLAR) for residential rooftop and ground-mounted PV installations in unincorporated Jefferson County, processed through the same Cityworks portal and valuation-based Total Valuation fee formula as the county's general Residential Building Permit. This is directly confirmed by the county's own published April 2026 Monthly Building Statistic Report, which lists three separate BP-SOLAR 'Solar Permit' cases issued that month (case numbers 26-0113, 26-0133, 26-0160), with recorded system valuations of $35,000 and $25,000. As with all other trades in unincorporated Jefferson County, the electrical interconnection portion is separately permitted and inspected by the Idaho Division of Occupational and Professional Licenses (DOPL), not the county.
EV Charger / EVSE Permit
Jefferson County has no dedicated EV-charger/EVSE building-permit case type (unlike its distinct BP-SOLAR Solar Permit) and does not itself issue electrical permits — installing a Level 2 or DC fast EV charger's dedicated circuit is handled entirely by the Idaho Division of Occupational and Professional Licenses (DOPL), the same as any other electrical work in unincorporated Jefferson County. A county Building Permit applies only if the installation is paired with new structural construction (e.g., a new carport or garage).
New residential construction activity
New privately-owned residential construction onlyHousing units authorized by building permits for new privately-owned residential construction — this is not total permit volume (no commercial permits or remodels).
- Latest month (2026-05)
- 39units
39 buildings · $10.1M valuation
- Trailing 12 months
- 271units
12 of 12 months reported · #18 in Idaho coverage by units
- Year to date (2026 YTD through 2026-05)
- 123units
123 buildings · $33.4M valuation
- Full year 2025
- 312units
298 buildings · $84.8M valuation
County-wide figures: Jefferson County, Idaho FIPS 16/051 verified against U.S. Census Bureau 2020 county reference file (www2.census.gov/geo/docs/reference/codes2020/cou/st16_id_cou2020.txt: 'ID|16|051|00399751|Jefferson County|H1|A'). Not to be confused with same-named Jefferson Counties in other states. Jefferson County Planning, Zoning & Building Department administers permits for unincorporated county land AND (under a separate service arrangement) provides building-permit processing support to the incorporated cities of Rigby, Menan, and Lewisville — this file covers ONLY the county's own unincorporated-area program.
Source: U.S. Census Bureau, Building Permits Survey (BPS), 2026-05 vintage. Census survey data — separate from the permit-requirements verification above. All Idaho building activity
Tips & gotchas
- Jefferson County Planning, Zoning & Building administers the building permit process for unincorporated county land AND, under a separate service arrangement, provides building-permit application processing for the incorporated cities of Rigby, Menan, and Lewisville — but this is co-administration, not annexation. The county publishes city-specific help documents (e.g., 'Rigby - Basement Finish or Residential Remodel Help information') and its own Building Permit Process document confirms that when a property is within incorporated city limits, the finished CO/CC documentation is forwarded to the city, which issues the Certificate of Occupancy itself. Rigby also maintains its own City Code Chapter 1 (Building Code and Regulations) and its own Planning & Zoning intake counter at 158 W. Fremont Ave — so Rigby is not a simple pass-through to the county.
- As of June 1, 2026, Jefferson County PZ&B took over processing all NEW mechanical (HVAC) permit applications for the City of Rigby specifically — implying Rigby (or another party) previously handled Rigby's own mechanical permits before that date. This is a recent, narrow expansion of the county's role for Rigby, not evidence the county issues mechanical permits for its own unincorporated area (it does not — see below).
- For UNINCORPORATED Jefferson County itself, electrical, plumbing, and mechanical (HVAC) permits are issued exclusively by the Idaho Division of Occupational and Professional Licenses (DOPL), not the county. This is stated plainly on the county's own Single Family Dwelling and ADU help documents.
- All construction in unincorporated Jefferson County must comply with the 2018 IRC (residential) / 2018 IBC (commercial), adopted via County Ordinance 2022-02, effective March 7, 2022.
- Applications go through the Jefferson County Cityworks public portal at https://app04.cityworksonline.com/CLIENT_JeffersonCoID-public/login — Chrome or Firefox required, and account activation is mandatory before submitting.
- Permits submitted before December 14, 2023 are not in the Cityworks system; call the department directly at 208-745-9220 for inspections on those older permits.
- A recorded warranty deed and either an Idaho Contractor's License or a completed Contractor Exemption form are required on every residential building permit application, in addition to the technical plan set.
- Central to cost planning: a 15% Plan Review Fee, a flat $30 GIS/Mapping Fee, and a flat $30 Technology Fee are added on top of the valuation-based building permit fee for every application.
- Minimum 24 hours' notice is required for any inspection request.