Commercial Building Permit (New Construction / Addition) in Unincorporated Jefferson County, Idaho

Unincorporated Jefferson County requires a commercial building permit (new construction / addition) for: Commercial Building Permit required for new commercial construction and additions (including interior remodels/tenant improvements, since no separate TI category exists) to commercial buildings in unincorporated Jefferson County; Commercial plans — which must include a code analysis stating Occupancy Class — must be designed and stamped by an Idaho-licensed architect; Plans must comply with the 2018 International Building Code (IBC) and 2018 International Fire Code (IFC); All mechanical system(s) must be permitted and inspected by the Idaho Division of Occupational and Professional Licenses (DOPL), per the county's own Commercial Help Information document — not submitted as part of the county's commercial building permit package; Register for and activate an account on the Jefferson County Cityworks public portal (Chrome or Firefox browser required) before applying; Submit Description of Work, Type of Structure, Fire Sprinkler System status, Occupancy Class, Construction Type, Designed Occupancy Load, Parcel Number/Size, County Zoning, flood zone status, full square footage by space type, height/setback dimensions, and utility information (sewer provider/permit, water source, heat system) as part of the online application; Site Plan showing all property lines, setbacks, easements, North arrow, existing/proposed structures with dimensions, driveway location, and canals/rivers/roads, plus overall parcel size; Recorded warranty deed demonstrating ownership or authorization to build; Idaho Contractor's License for the contractor of record; Access Permit from Jefferson County Public Works (county roads) or Idaho Transportation Department (state highways) if the project needs new/modified access; Septic Permit (approved) from Eastern Idaho Public Health if the structure has plumbing, or an EIPH authorization-to-connect letter if tying into an existing/private sewer system; If in a mapped flood zone: Flood Plain Development Permit and Elevation Certificate; If the applicant is leasing (not the property owner), Written Consent from the property owner is a recommended attachment — the only place the county's own documentation directly acknowledges a tenant-driven commercial application scenario; Minimum 20 business days for plan review — confirmed independently by both the county's Commercial Help Information sheet ('Minimum 20 business days may be required for plan review') and its Building Permit Process document ('approximately 20 business days for a commercial building permit application'). If your project isn't listed, confirm with Jefferson County Planning, Zoning & Building Department at 208-745-9220 before starting work.

In Unincorporated Jefferson County, the published Building permit fee — Total Valuation (same general table used for all county building permits, including residential) is: Valuation-based per Jefferson County Fee Schedule 2026, Exhibit A — e.g. $536.90 for the first $40,000 plus $9.92 per additional $1,000 up to $100,000; $1,132.10 for the first $100,000 plus $7.71 per additional $1,000 up to $500,000; see the file's residential-building-permit entry for the full tier table. Additional published fees: Plan Review Fee — 15% of Building Permit Fee; GIS/Mapping Review Fee — $30.00 added to each application; Technology Fee — $30.00 added to each application; Inspection Fee — $90.00; Re-Inspection Fee — $90.00. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Approximately 20 business days for plan review, per the county's Building Permit Process document — five business days longer than the 15-business-day figure for non-commercial (residential) permits. The county's Commercial Help Information sheet separately states a 'minimum 20 business days may be required for plan review.' Source: Jefferson County 'Building Permit Process: Plan Submittal to CO Issuance' (Date of Form: June 26, 2025) and 'Commercial – New Construction / Addition Help Information' (Date of Form: January 2, 2024).

You'll need: Commercial – New Construction / Addition Help Information (Date of Form: January 2, 2024); Architect-Stamped Commercial Plans (with Code Analysis / Occupancy Class); Engineered Truss Design and Truss Layout; Site Plan; Idaho Contractor's License; Recorded Warranty Deed; Water and Fire Suppression Plan. Depending on your project, Unincorporated Jefferson County may also ask for: Guide to Determine Building Permit Application Jurisdiction, Category and Type (Date of Form: June 26, 2025); Septic Permit (or EIPH Authorization to Connect); Access Permit; Written Consent. See the required-documents checklist on this page for details on each.

Unincorporated Jefferson County requires 11 inspection(s) for a commercial building permit (new construction / addition), in order: Layout Inspection, Footing Inspection, Foundation Inspection, Sheathing Inspection, State Rough-In Inspections (Electrical, Plumbing, HVAC), Framing Inspection, Insulation Inspection, Drywall Inspection, State Final Inspections, Health Department Final, Final Inspection by Building Department. Schedule each through Jefferson County Planning, Zoning & Building Department (208-745-9220).

Apply through Jefferson County Planning, Zoning & Building Department at 210 Courthouse Way, Suite 170, Rigby, ID 83442. Phone: 208-745-9220. Office hours: Mon–Fri 9:00 AM – 5:00 PM. Official information: https://www.jcgov.us/231/Planning-Zoning-Building.

No. The county's own 'Guidance to Determine Building Permit Application Jurisdiction, Category, and Type' document lists only two Commercial permit types — 'Commercial – New Construction / Addition' and 'Commercial – Signs & Towers' — and this is confirmed by real issued-permit records (the April 2026 Monthly Building Statistic Report shows only BPC-NEW/RIGBY-COMM commercial building-permit codes, no separate remodel/TI code). A commercial interior build-out or tenant improvement in unincorporated Jefferson County is filed under the same 'Commercial – New Construction / Addition' application category. Source: Jefferson County 'Guidance to Determine Building Permit Application Jurisdiction, Category and Type' (Date of Form: June 26, 2025) and April 2026 Monthly Building Statistic Report.

Plans must be designed and stamped by an Idaho-licensed architect and must include a code analysis stating Occupancy Class, and must comply with the 2018 IBC and 2018 IFC. Required attachments include the architect-stamped plans, engineered truss design and truss layout, a site plan, an Idaho Contractor's License, a recorded warranty deed, and a Water and Fire Suppression Plan. Source: Jefferson County 'Commercial – New Construction / Addition Help Information' (Date of Form: January 2, 2024).