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Residential Building Permit (New Construction / Remodel Changing Outside Dimensions) in Unincorporated Franklin County, Idaho

Required for new construction of any building, structure, or mobile home, or for remodels that change a structure's outside dimensions, anywhere in unincorporated Franklin County, per Franklin County Code § 150.015(A). Fee is 1% of the assessed value of the proposed building per § 150.018.

Verified 2026-07-13 · Source

When you need this permit

  • New building, structure, or mobile home construction, OR a remodel that changes outside dimensions of an existing structure
  • Structures exceeding 200 square feet require a permit, per the county's Building Permit Information and Process document
  • Parcel must be an eligible 'building lot' (all county land is zoned agriculture by default; parcel-split history must be researched back to June 1993, or contact the Planning and Zoning Administrator to begin the rezone process)
  • Septic Permit (from Southeastern Idaho Public Health) required before a building permit can be issued
  • Copy of deed required
  • Written approval from the Idaho Department of Health / Southeastern District Health Department required whenever culinary water, sanitary sewer, or septic system work is part of the project, per § 150.017(C)

Required documents

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Fee schedule

Building Permit FeeFranklin County Code § 150.018, 'payable when the application is made for any construction defined in § 150.015' (Ord. 2016-2-22, passed 2-22-2016) — consistent with the county's own Building Permit Information and Process document, which states 'Building Permit fee is 1% of the assessed value.'
1% of the assessed value of the proposed building

Review timeline

Plan reviewUnincorporated Franklin County’s published plan-review target
Up to 31 business days

How long did your Residential Building Permit (New Construction / Remodel Changing Outside Dimensions) permit actually take in Unincorporated Franklin County?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

  1. 1

    Footing/Setback

    Excavation to proper depth (30 inches below final grade); excavation must be a minimum of 80 feet from the center of the county road or 50 feet from the fence, whichever is furthest; rebar tied and lifted approximately 3 inches; UFER electrical ground in place; no frost in the ground; rebar dowels set 24 inches on center after concrete is poured. Per the county's own Inspection Process document.

  2. 2

    Foundation

    Forms in place, rebar in position both horizontal and vertical (24 inches o.c.), any blockouts in place, cold joints doweled. Per the county's own Inspection Process document.

  3. 3

    Framing/Mechanical

    Sheathing inspection before house-wrap is applied; framing/fire-blocking/bracing inspection after roof and windows are in but before insulation; rough electrical and plumbing inspected in place; rough mechanical (ducts, flues, appliances) in place. Per the county's own Inspection Process document.

  4. 4

    Sheetrock

    After sheetrock is installed, before taping. Per the county's own Inspection Process document.

  5. 5

    Final

    Prior to moving in, with finish grade and building completed; final electrical, plumbing, and mechanical finals completed. Per the county's own Inspection Process document.

See the full Unincorporated Franklin County inspection guide — scheduling & re-inspection fees →

Tips

  • The permit holder must call the Building Inspector at (208) 221-6149 between 9 AM and 5 PM, Monday-Friday, giving 24-hour notice to schedule each required inspection, per the county's own Inspection Process document.
  • The county's Building Permit Application form states work must commence within 180 days and the permit expires in one year, while the codified ordinance (§ 150.017(G)) states permits expire if work has not begun within 6 months — these two published figures conflict and neither document is dated as controlling; confirm the current operative rule directly with the Building Inspector before relying on either.
  • All county land is zoned agriculture by default. Before applying, confirm your parcel is an eligible 'building lot' — if it was split or broken off another parcel, you may need to work with the Planning and Zoning Administrator (also Randy Henrie) to change its zoning status.
  • A Septic Permit from Southeastern Idaho Public Health is a hard prerequisite — the county will not issue a building permit without it.
  • IMPORTANT: The City of Preston (the county seat, where the county Building Department's office is physically located) has its OWN separate Building Department and Building Inspector (Curt Fuller) — properties located WITHIN Preston city limits must apply to the City of Preston, not this county department. Confirm whether your parcel is inside or outside Preston's city limits before applying.

Frequently asked questions

Unincorporated Franklin County requires a residential building permit (new construction / remodel changing outside dimensions) for: New building, structure, or mobile home construction, OR a remodel that changes outside dimensions of an existing structure; Structures exceeding 200 square feet require a permit, per the county's Building Permit Information and Process document; Parcel must be an eligible 'building lot' (all county land is zoned agriculture by default; parcel-split history must be researched back to June 1993, or contact the Planning and Zoning Administrator to begin the rezone process); Septic Permit (from Southeastern Idaho Public Health) required before a building permit can be issued; Copy of deed required; Written approval from the Idaho Department of Health / Southeastern District Health Department required whenever culinary water, sanitary sewer, or septic system work is part of the project, per § 150.017(C). If your project isn't listed, confirm with Franklin County Building Department at (208) 221-6149 before starting work.

Per Franklin County Code § 150.018, the Building Permit Fee is 1% of the assessed value of the proposed building, payable when the application is submitted.

Unincorporated Franklin County's published plan-review target for a residential building permit (new construction / remodel changing outside dimensions) is Up to 31 business days.

You'll need: Franklin County Building Permit Application; Copy of Deed; Building plans (Site Plan, Foundation Plan, Floor Plans, Slice Plan, Elevation Plans, Electrical Plan, Roof Plan); Signature Checklist / Building Permit Checklist; Septic Permit. See the required-documents checklist on this page for details on each.

Unincorporated Franklin County requires 5 inspection(s) for a residential building permit (new construction / remodel changing outside dimensions), in order: Footing/Setback, Foundation, Framing/Mechanical, Sheetrock, Final. Schedule each through Franklin County Building Department ((208) 221-6149).

Apply through Franklin County Building Department at 561 West Oneida, Preston, ID 83263. Phone: (208) 221-6149, email: plans@fcidaho.us. Office hours: Monday–Friday, 9:00 AM to 5:00 PM, per franklincountyidaho.org/departments/building_department.php. Building Inspector: Randy Henrie, who also serves as the county's Planning and Zoning Administrator, per the county's own Building Permit Information and Process document (fax: 208-852-1096)..

Unincorporated Franklin County, Idaho has adopted: International Building Code (IBC), including all rules promulgated by the Idaho Building Code Board to provide equivalency with ADA and Federal Fair Housing Act accessibility guidelines — Franklin County Code of Ordinances § 150.001(A)(1). The county code adopts codes by reference to 'the approved editions... as adopted by the state or the state's Building Code Board' rather than citing a specific numbered edition itself; per § 150.001(B), adopted codes 'shall be deemed superseded by successive versions... as they are adopted or approved by the state's Building Code Board, effective on the date any such codes are made effective by the state's Building Code Board' — meaning Franklin County's in-force edition tracks the Idaho Division of Building Safety's statewide adoption automatically.; International Residential Code (IRC), Parts I-VI — Franklin County Code § 150.001(A)(2), same state-tracking mechanism per § 150.001(B).; International Energy Conservation Code (IECC) — Franklin County Code § 150.001(A)(3).; International Mechanical Code (IMC) — Franklin County Code § 150.001(A)(4).; International Fuel Gas Code (IFGC) — Franklin County Code § 150.001(A)(5).; International Fire Code (IFC) — Franklin County Code § 150.001(A)(6).; NOTE: Franklin County's ordinance text (Ord. 2010-6-28; originally Ord. 2003-1) does not itself state specific edition years (e.g. '2021 IBC') — it adopts by reference whatever edition the Idaho Building Code Board has currently approved statewide. This file therefore does not fabricate a specific year for each code; the Idaho Division of Building Safety's current statewide adoption (per dopl.idaho.gov/bld) governs and should be checked directly for the in-force edition as of any given date.. Local amendments apply — see the Unincorporated Franklin County overview page for the full list.

No. The City of Preston operates its own separate Building Department with its own Building Inspector (Curt Fuller), distinct from the county's Building Inspector (Randy Henrie), even though both offices are located in the town of Preston. Properties inside Preston's city limits must apply through the City of Preston's own permit process (via CloudPermit, per prestonidaho.net), which requires a Preston City Business License for contractors and references the City Engineer and Public Works Department — requirements not part of the county's process.

Sources & verification

Verified against official sources. Last reviewed 2026-07-13.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Unincorporated Franklin County building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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