Commercial Building Permit (New Construction / Addition / Shell Building) in Twin Falls, Idaho

Twin Falls requires a commercial building permit (new construction / addition / shell building) for: Building permit required for any new commercial construction, building addition, or shell building; select the New, Addition, or Shell Building subtype on the New Commercial Building Permit Application; Plans reviewed against the 2018 IBC with Idaho amendments and City of Twin Falls Design Criteria: Commercial (Wind Exposure B, minimum 25 psf uniformly distributed roof design load, 24-inch frost depth, 1,500 psf presumed soil bearing pressure, Climate Zone 5B); Required submittal items due at time of application: Completed & Signed Application, Construction Plan Sheets (Sheet Prefix G/Contact-Cover-General Notes, C/Civil, D/Demolition, A/Architectural, E/Electrical, M/Mechanical, P/Plumbing, S/Structural, L/Landscape; PH/Phasing Plan if phasing multiple structures on one lot), Calculations, and Supplemental Information; FP/Fire Protection and I/Site Lighting are preferred standalone sheets; Signed Affidavit of Legal Interest required if the property owner is not the applicant; Development Agreement required for any project needing public infrastructure; Wastewater Discharge Survey required for industrial projects only; Sewer Capacity Fee Worksheet required; Fire Sprinkler, Fire Alarm, and Elevator plans must be submitted to the State of Idaho for review (not the City of Twin Falls), per IBC Section 105.3 as noted on the application; Applications for any proposed work are deemed abandoned after 180 days from the date of filing unless pursued in good faith or a permit has been issued; a written extension of up to 90 additional days may be granted upon a showing of justifiable cause; Commercial multi-family (3+ unit) buildings use the separate New Commercial Multi-Family Building Permit Application; each structure on a lot requires its own separate permit and full discipline-specific document set, and combined submittal packages for multiple buildings are not accepted; Registered contractor registration number and expiration must be provided; a primary licensed design professional (and, where applicable, a separate structural licensed design professional) must be identified on the application. If your project isn't listed, confirm with City of Twin Falls Building Safety Department at (208) 735-7238 before starting work.

In Twin Falls, the published Building Permit Fee — valuation $1 to $500 is: $22.00. Additional published fees: Building Permit Fee — valuation $501 to $2,000 — $22.00 for the first $500, plus $2.75 for each additional $100 or fraction thereof; Building Permit Fee — valuation $2,001 to $25,000 — $63.00 for the first $2,000, plus $12.50 for each additional $1,000 or fraction thereof; Building Permit Fee — valuation $25,001 to $50,000 — $352.00 for the first $25,000, plus $9.00 for each additional $1,000 or fraction thereof; Building Permit Fee — valuation $50,001 to $100,000 — $580.00 for the first $50,000, plus $6.25 for each additional $1,000 or fraction thereof; Building Permit Fee — valuation $100,001 to $500,000 — $895.00 for the first $100,000, plus $5.00 for each additional $1,000 or fraction thereof; Building Permit Fee — valuation $500,001 to $1,000,000 — $2,855.00 for the first $500,000, plus $4.25 for each additional $1,000 or fraction thereof; Building Permit Fee — valuation $1,000,001 and up — $4,955.00 for the first $1,000,000, plus $2.75 for each additional $1,000 or fraction thereof; Commercial Plan Review Fee — 65% of the building permit fee; Additional Plan Review Fee — $50.00; Re-inspection Fee — $50.00; Temporary Certificate of Occupancy application (non-single-family & duplex permits) — $1,200.00; Temporary Certificate of Occupancy retainer (non-single-family & duplex permits) — 1.50% of project value ($5,000 minimum; $75,000 maximum). These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

New complete commercial buildings and additions are published at 5 weeks to first review, subject to current workload and project complexity. This is the time to first review comments, not a guarantee of total time to permit issuance, since that also depends on revision cycles. Source: City of Twin Falls Building Applications & Forms page (Commercial plan review timelines table).

You'll need: New Commercial Building Permit Application; Construction Plan Sheets; Calculations; Supplemental Information. Depending on your project, Twin Falls may also ask for: Commercial Development Guide. See the required-documents checklist on this page for details on each.

Twin Falls requires 7 inspection(s) for a commercial building permit (new construction / addition / shell building), in order: Footing/Foundation, Shear, Framing, Fire (Alarm / Sprinkler / Kitchen Hood, as applicable), Engineering (Storm Water / Site / Right-of-Way / Flood Plain), Planning & Zoning (Landscaping / Trash Enclosures), Final (Building) / Certificate of Occupancy. Schedule each through City of Twin Falls Building Safety Department ((208) 735-7238).

Apply through City of Twin Falls Building Safety Department at 203 Main Avenue East, 2nd Floor of City Hall, Twin Falls, ID 83301 (P.O. Box 1907, Twin Falls, ID 83303-1907). Phone: (208) 735-7238, email: bsdpermits@tfid.org. Office hours: Building Safety Department, 2nd Floor of City Hall, 203 Main Avenue East, Twin Falls, ID 83301. Dedicated inspection request lines: Building Inspection (208) 735-7333, Plumbing Inspection (208) 735-7299, Mechanical Inspection (208) 735-7289, Electrical Inspection (208) 735-7235.. Official information: https://www.tfid.org/141/Building-Safety-Department.

Twin Falls, Idaho has adopted: Idaho Building Code Act (Idaho Code Title 39, Chapter 41) makes building code standards a matter of statewide concern; local governments that issue building permits and perform code enforcement must adopt the International Building Code and Idaho Residential Code (Parts I-III and IX) and the Idaho Energy Conservation Code as amended by the Idaho Building Code Board through negotiated rulemaking, and may not adopt subsequent IRC/IECC residential provisions not yet adopted by the Board. Source: Idaho Legislature, Idaho Code Title 39 Chapter 41 (39-4116, Local Government Adoption and Enforcement of Building Codes), https://legislature.idaho.gov/statutesrules/idstat/title39/t39ch41/; 2018 International Building Code (IBC), including accessibility appendices, adopted and incorporated by reference statewide with Idaho amendments; locally administered and enforced by the City of Twin Falls Building Safety Department for commercial construction within city limits. Source: City of Twin Falls Design Criteria: Commercial page and Idaho Building Code Act (Title 39 Ch. 41); 2018 International Residential Code (IRC), Parts I-VI and IX, Appendices A, B and G, with Idaho State amendments, adopted and locally administered by the City of Twin Falls for one- and two-family dwellings and townhouses within city limits. Source: City of Twin Falls Design Criteria: Residential page; 2018 International Energy Conservation Code (IECC), with Idaho State amendments, locally administered by the City of Twin Falls for residential construction. Source: City of Twin Falls Design Criteria: Residential page; 2023 National Electrical Code (NEC), per Idaho Rules and Amendments, locally administered and inspected by the City of Twin Falls Building Safety Department (dedicated Electrical Inspection line). Source: City of Twin Falls Design Criteria: Residential page and Inspections page; 2017 Idaho State Plumbing Code, locally administered and inspected by the City of Twin Falls Building Safety Department (dedicated Plumbing Inspection line). Source: City of Twin Falls Design Criteria: Residential page; City of Twin Falls has assumed local jurisdiction for issuing and inspecting building, electrical, plumbing, and mechanical permits within city limits (dedicated Building, Plumbing, Mechanical, and Electrical inspection phone lines are all City of Twin Falls Building Safety Department lines). The Idaho Division of Occupational and Professional Licenses (DOPL) separately registers/licenses electrical, plumbing, and HVAC contractors statewide (a distinct function from the City's permit issuance and inspection authority); DOPL's own Permits and Inspections program applies only in jurisdictions that have NOT assumed local authority, and DOPL confirms permit/inspection jurisdiction 'varies widely' by city/county assumption of authority. Source: DOPL Permits and Inspections page, https://dopl.idaho.gov/plb/plb-permits-and-inspections/, cross-checked against City of Twin Falls Inspections page listing City-run Building/Plumbing/Mechanical/Electrical inspection lines. Local amendments apply — see the Twin Falls overview page for the full list.

No. Fire Sprinkler, Fire Alarm, and Elevator plans must be submitted to the State of Idaho for review, separate from the City of Twin Falls building permit process, per IBC Section 105.3 as noted on the New Commercial Building Permit Application.