You are viewing the permanent link for the record currently in effect, published 2026-07-07.
Unincorporated Twin Falls County building permits
VerifiedUnincorporated Twin Falls County, Idaho — as published 2026-07-07.
Verified 2026-07-08 · Source
Codes adopted
Permit types & fees
Residential Building Permit (New Construction / Addition)
VerifiedRequired for new single-family dwellings, additions, garages, carports, covered decks/patios, and manufactured home placements in unincorporated Twin Falls County. Twin Falls County Community Development Services — Building Department reviews plans and issues permits under the 2018 IBC/IRC with Idaho Amendments. Applications may be submitted by email/upload or through the Citizens Connect permit portal.
Verified 2026-07-08 · Source
Requirements
- Building permit required for new residential construction, additions, garages/carports, covered decks/patios, and any deck with a walking surface more than 30 inches above grade
- Parcel number (obtained from the County Assessor's Office)
- Copy of the deed showing ownership, including legal description (obtained from the County Clerk's Office)
- Authorization Form signed by the property owner if the applicant is not the owner
- Two (2) sets of plans drawn to 1/4 inch = 1'0" scale (or computer-generated plans at not less than 1/8 inch = 1'0"), submitted as a PDF for digital submittal
- Site plan showing property lines, lot dimensions, survey corner stakes, easements, rights-of-way, well/septic locations, all existing structures, proposed structure with dimensions and setbacks, driveway, and surface drainage
- Two (2) site plans stamped approved by the South Central Public Health District
- Building plans: footing/foundation plan with reinforcement, floor plan, egress window/smoke/CO detector locations, floor framing, crawlspace venting, beam/header sizing, stair details, wall shear bracing, elevations (minimum 2), and a completed energy conservation certification (RESCheck or prescriptive)
- Highway District, Canal Company, and Fire District approval/comment letters
- FEMA Elevation Certificate required before permit issuance if the parcel is within 100 feet of a major waterway (and again before final inspection)
- Architect/engineer-stamped plans required only if the building is more than two stories or of unusual design requiring professional structural assistance
- Plan Review Fee (35% of the building permit fee, or $100, whichever is greater) is due at time of submittal and is non-refundable
Required documents
- RequiredResidential Building Permit Application (Updated 9/2025, fillable PDF)Twin Falls County residential building permit application; available at twinfallscounty.org/building_department/applications/
- RequiredBuilding Applications Submittal Checklist (5/2024)Lists all required submittal items for residential/commercial building permits, interior remodels, manufactured homes, and demolition/relocation permits, plus agency contact list
- OptionalResidential BP Information Handout (Rev. 1/2014)General guide to the residential permitting process, minimum plan requirements, design criteria, and inspection procedures
- OptionalExample Site PlanSample site plan illustrating required elements; available at twinfallscounty.org/building_department/applications/
- OptionalAuthorization FormRequired if the applicant is not the property owner of record
- RequiredSouth Central Public Health District Approval / Septic PermitTwo stamped/approved site plans required with the application; contact 208-737-5900 or 208-737-5918
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building permit fee — R-3 (one- and two-family residential), valuation basis, Type VB construction | $82.65 per sq ft (Single Family Home); Finished Basement $42.78/sq ft; Unfinished Basement $32.29/sq ft; Carport/Lean-to $32.12/sq ft; Ag Shop/Res Shop $41.71/sq ft; Deck/Covered Porch/Patio $18.66/sq ft | Twin Falls County Community Development Services Fee Schedule, effective September 1, 2025 (TFCO-BLD-FEES-2025-base-FINAL.pdf). Other construction types (VA, IIIB, IIIA, IIB, IIA, IB, IA) priced separately per the same schedule. |
| Residential Plan Review Fee (NEW, non-refundable) | 35% of the building permit fee, or $100.00, whichever is greater | Due at time of plan submittal; effective September 1, 2025 fee schedule. Not refundable once review has been completed. |
| Inspection Fee | $55.00 | Twin Falls County 2025 Fee Schedule |
| Replacement Plan Set | $50.00 | Twin Falls County 2025 Fee Schedule |
Commercial Building Permit (New Construction / Tenant Improvement)
VerifiedRequired for new commercial buildings, tenant improvements, and change-of-use projects in unincorporated Twin Falls County. Governed by the 2018 International Building Code (IBC) with Idaho Amendments. A separate Commercial Plan Review Fee applies (65% of the building permit fee, or $200, whichever is greater). Applications submitted by email/upload or through the Citizens Connect permit portal.
Verified 2026-07-08 · Source
Requirements
- Building permit required for new commercial construction, tenant improvements, additions, and change-of-occupancy projects
- Commercial Building Permit Application (2025 fillable form)
- Plans Analysis required for all commercial building plans
- Plans stamped by an Idaho-licensed architect or engineer where required
- Site plan, floor plans with dimensions, elevation views, footing/foundation dimensions with reinforcing, typical construction detail, cross-section and stair detail, truss/floor joist details
- South Central Public Health District approval/permit and approved stamped site plan
- Highway District, Canal Company, and Fire District approval/comment letters
- Deed showing ownership; Authorization Form if applicant is not the property owner
- Commercial Plan Review Fee (65% of building permit fee or $200, whichever is greater) due at time of plan submittal
Required documents
- RequiredCommercial Building Permit Application (2025-09 fillable form)Twin Falls County commercial building permit application; available at twinfallscounty.org/building_department/applications/
- OptionalCommercial BP Information Handout (Rev. 1/2014)General guide to the commercial permitting process — plan requirements, design criteria, and inspection procedures
- RequiredBuilding Applications Submittal Checklist (5/2024)Lists required submittal items for residential/commercial building permit applications
- RequiredSouth Central Public Health District ApprovalRequired for commercial building permits; contact 208-737-5900
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building permit fee — Commercial occupancy groups (A, B, E, F, H, I, M, S, U), valuation basis | Per-square-foot rate varies by occupancy group and construction type (Type IA through VB); e.g. Business (B): $90.88–$132.95/sq ft; Mercantile (M): $63.76–$95.14/sq ft — see full 2025 fee schedule for all groups/types | Twin Falls County Community Development Services Fee Schedule, effective September 1, 2025 (TFCO-BLD-FEES-2025-base-FINAL.pdf) |
| Commercial Plan Review Fee | 65% of the building permit fee, or $200.00, whichever is greater | Twin Falls County 2025 Fee Schedule; unchanged from the prior 2021 schedule |
| Commercial Demolition | Based on valuation | Twin Falls County 2025 Fee Schedule |
Mechanical / HVAC Permit
VerifiedRequired for heating, ventilation, air conditioning, and fuel gas installations in unincorporated Twin Falls County. Unlike electrical and plumbing (which are administered statewide by the Idaho Division of Building Safety), Mechanical/HVAC permits in Twin Falls County are issued and inspected directly by the county's own Building Department under a locally-run program, using the county's own application and per-square-foot/per-item fee schedule.
Verified 2026-07-08 · Source
Requirements
- Required for new HVAC installations, replacement/retrofit of mechanical equipment, gas lines, solid fuel/gas heating appliances, and hydronic heating systems
- Residential/Commercial HVAC Permit Application listing parcel number, structure type, and description of work
- Idaho contractor registration number and expiration date required for contractor-performed work
- Property address must be posted at the public road entrance prior to first inspection
Required documents
- RequiredMechanical Permit Application (Updated 10/2021, includes HVAC Fee Schedule)Twin Falls County residential/commercial HVAC permit application with attached fee schedule; still the current form referenced by the county's 2025 fee schedule. Available at twinfallscounty.org/building_department/applications/
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Residential HVAC — New, single-family/duplex/townhome, based on living space | Up to 1,500 sq ft: $120.00; 1,501–2,500 sq ft: $170.00; 2,501–3,500 sq ft: $230.00; 3,501–4,500 sq ft: $280.00; over 4,500 sq ft: $280.00 plus $50.00 per additional 1,000 sq ft or portion thereof | Twin Falls County 2025 Fee Schedule (TFCO-BLD-FEES-2025-base-FINAL.pdf), 'Mechanical Permits' section, current from 2025 |
| Replacement or Retrofit Systems (existing structures) | $60.00 plus $10.00 per additional piece of mechanical equipment | Twin Falls County 2025 Fee Schedule |
| Miscellaneous Items | $60.00 plus $10.00 per additional piece | Twin Falls County 2025 Fee Schedule |
| Commercial HVAC | Based on construction valuation chart | Twin Falls County 2025 Fee Schedule |
Personal Use Energy Project Permit (Rooftop/Ground-Mount Solar)
VerifiedRequired for residential ('personal use') solar and wind energy systems in unincorporated Twin Falls County under Title 8, Chapter 21 (Energy Production) of the County Code, adopted March 2024. Per County Code Section 8-21-3(B): 'A siting permit and building permit is required prior to installation of any personal use energy project.' A personal-use project is a small system (per the ordinance's own drafting materials, capacity of 200 kW or less, footprint under 200 sq ft, associated with a single-family dwelling) — distinct from Small Scale (200 kW-10 MW) and Large Scale commercial energy projects, which instead require a Conditional Use Permit through the Planning & Zoning Division. The building-permit component is issued by the same Building Department and reviewed under the 2018 IBC/IRC as the county's general residential-building-permit; electrical interconnection work is permitted separately by the Idaho Division of Building Safety (state), not the county.
Verified 2026-07-20 · Source
Requirements
- A Siting Permit (Planning & Zoning) AND a Building Permit (Building Department) are both required prior to installing a personal-use solar or wind energy system, per Twin Falls County Code Section 8-21-3(B)
- Personal-use energy project: total capacity of 200 kW or less, not encumbering more than 200 sq ft, associated with a single-family dwelling — larger systems must instead go through the Small Scale (200 kW-10 MW) or Large Scale Conditional Use Permit process under Chapter 21
- Applicant must coordinate/document any state or federal permits or licenses related to the project and provide copies to the county (Section 8-21-3(C))
- Site review may be required for proposed electric generating projects per Section 8-21-3(D)
- The building-permit component follows the same submittal requirements as the general residential-building-permit entry (site plan, structural details for roof/ground mounting) where applicable to the racking/mounting structure
- Electrical permitting/inspection for the PV interconnection is handled by the Idaho Division of Building Safety (state), not Twin Falls County — see the county's electrical-permit sourcing on the residential-building-permit entry
Required documents
- RequiredSiting Permit Application (Personal Use Energy Project)Planning & Zoning Division application for the siting-permit component required under County Code Section 8-21-3(B)
- RequiredBuilding Permit ApplicationSame Building Department application/checklist used for general residential construction, for the structural/mounting component
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Personal Use (Wind/Solar) Siting Permit | $675.00 | Twin Falls County Community Development Services Fee Schedule, effective 9/1/2025 (TFCO-BLD-FEES-2025-base-FINAL.pdf), Zoning Fees table — confirmed by rendering the fee-schedule PDF page to an image and reading the table directly, since the PDF's text layer garbles the multi-column row/value alignment for this section. Flat fee, distinct from the Conditional Use Small Scale (Wind/Solar) fee ($3,000 plus $75/tower or $50/acre covered solar), which applies only to systems above the personal-use size threshold. |
| Building Permit Fee (structural/mounting component) | Valuation-based per the general residential building-permit fee schedule | No separate solar-specific building-permit fee line was found on the county's fee schedule; the structural/mounting portion of a personal-use system is billed under the same valuation-based table as residential-building-permit |
Electric Vehicle (EV) Charging Station / EVSE Permit
VerifiedUnincorporated Twin Falls County does not itself issue electrical permits. Per the county's own building-permit documentation (confirmed on the paired solar-pv-permit entry in this file), electrical permitting and inspection -- which covers EV charging station/EVSE circuit installation -- is handled by the State of Idaho's electrical permitting program (Division of Occupational and Professional Licenses, Electrical Bureau, formerly the Division of Building Safety), not the Twin Falls County Building Department. No county-specific or state-published EV-charger/EVSE line item, distinct fee, or dedicated application was found; EVSE circuits are permitted as ordinary electrical work under the state's standard Electrical Permit Application.
Verified 2026-07-20 · Source
Requirements
- No standalone EV charger/EVSE permit application exists at the county or state level; EVSE circuit installation is permitted through the State of Idaho's standard Electrical Permit Application
- Apply through the Idaho Division of Occupational and Professional Licenses (DOPL), Electrical Bureau -- not Twin Falls County -- since the county does not administer its own electrical permitting program
- A licensed electrical contractor typically pulls the permit; a Homeowner Electrical Permit Application option also exists for owner-occupied residential work
- EVSE branch-circuit and disconnect requirements follow the National Electrical Code Article 625 (Electric Vehicle Power Transfer System) provisions as adopted by the state electrical program
Required documents
- RequiredElectrical Permit Application (State of Idaho, DOPL Electrical Bureau)Standard state electrical permit application used for all electrical work in unincorporated Twin Falls County, including EV charger circuits; not a county-issued document
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| State Electrical Permit — Existing Dwelling Unit Permit (residential EVSE circuit added to an existing home) | $65.00 per inspection (flat; no per-branch-circuit surcharge) | Idaho Administrative Code, IDAPA 24.39.10, Section 500.02.a.ii (Rules of the Idaho Electrical Board, official current rule, effective 3-28-23), adminrules.idaho.gov (https://adminrules.idaho.gov/rules/current/24/243910.pdf) — directly re-chased and confirmed against the authoritative current rule text, replacing the vague "use the DOPL calculator" placeholder. Fee is set and collected by the State of Idaho (DOPL), not Twin Falls County. |
| DOPL Electrical Permit — Other Installations (Including Industrial and Commercial) Permit (new construction, commercial, or multi-family EVSE) | Wiring cost up to $10,000: $60 plus 2% of total wiring cost; $10,001-$100,000: $260 plus 1% of excess over $10,000; over $100,000: $1,160 plus 0.5% of excess over $100,000 | Idaho Administrative Code, IDAPA 24.39.10, Section 500.02.b, adminrules.idaho.gov (official current rule, effective 3-28-23) — same statewide DOPL mechanism documented for other Idaho jurisdictions in this corpus. |
Sources & verification
Verified against official sources. Last reviewed 2026-07-08.
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 Twin Falls County building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.