Residential Detached Accessory Building Permit (Shed, Garage, Deck, Pool) in Twin Falls, Idaho
VerifiedRequired for detached accessory structures over 200 square feet (garages, sheds, carports, gazebos, greenhouses, detached decks) and pools greater than 24 inches deep on residential property in Twin Falls. Reviewed against the 2018 IRC and IECC with Idaho amendments.
Verified 2026-07-03 · Source
When you need this permit
- Building permit required for residential detached accessory buildings over 200 square feet, or any pool greater than 24 inches deep
- Structure must be sited a minimum of 10 feet from any part of the house (measured to the edge of the house or an existing covered porch/patio post)
- Structures more than two stories, over 10 feet single-story wall height, or exceeding prescriptive code requirements require plans and calculations engineered and stamped by an Idaho-licensed engineer or architect
- Plans designed to the 2018 IRC and IECC with Idaho amendments
- Energy compliance required via prescriptive approach or ResCheck
- When increasing building square footage on the property by more than 25%, curb, gutter, and sidewalk are required in most zones (deferral available in areas where none exist, via notarized Warranty Deed)
- Solid-surface driveways required for all garages used for vehicle parking/maneuvering
- Verified compliance with setbacks, easements, and flood plain status required as part of Planning and Zoning review
- Fire Department review of fire hydrant locations; additional fire protection may be required if the detached building exceeds 56,000 cubic feet
- All permits expire 180 days from issuance or the date of the last inspection
Required documents
- Required
Residential Detached Accessory Building Permit Application
City of Twin Falls application covering detached garage, carport, shed, pool, deck, and misc. fence/pool/deck permits; submit via bsdpermits@tfid.org or CityWorks portal
- Required
Residential Detached Accessory Building Checklist
Designer-completed checklist covering site plan, foundation/floor framing plan, and floor/roof framing plan requirements
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building Permit Fee — valuation $1 to $500 | $22.00 | Project value includes total value of work for which the permit is issued (electrical, gas, mechanical, plumbing, equipment, permanent systems, materials and labor), excluding only land value, per COTF Resolution No. 2024-011. City of Twin Falls Residential Detached Accessory Building Application |
| Building Permit Fee — valuation $501 to $2,000 | $22.00 for the first $500, plus $2.75 for each additional $100 or fraction thereof | City of Twin Falls Master City-Wide Fee Schedule |
| 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 | City of Twin Falls Master City-Wide Fee Schedule |
| Residential Plan Review Fee | 30% of the building permit fee | City of Twin Falls Master City-Wide Fee Schedule |
Review timeline
10–10 business days
Twin Falls’s published plan-review target
Inspection process
- 1
Foundation/Footing
Before concrete pour; required expanded footing dimensions, reinforcement type/size/location, and hold-downs verified per plans
- 2
Framing
Wall bracing, truss layout, header locations verified; all rough-in inspections for any MEP work must be signed off first
- 3
Final / Certificate of Completion
Completed structure verified against approved plans; a Certificate of Completion is issued after all inspections pass
Tips
- Detached decks, garages, and sheds use this application (not the Residential Addition applications, which are for structures attached to the main dwelling).
- A Special Use Permit may be required in certain zones if the accessory building exceeds a certain size — check with City staff.
- New accessory dwelling units require smoke detectors powered from building wiring, interconnected, with battery backup, per this application's ADU note.
- Digital plan submittal (PDF saved directly from CAD) is preferred over scans for faster processing; email to bsdpermits@tfid.org.
Frequently asked questions
- Do I need a permit for a shed in Twin Falls?
- A building permit is required for any detached accessory structure over 200 square feet, including sheds. Sheds 200 square feet or less do not require a permit under this threshold, per the City of Twin Falls Permit Requirements page and Residential Detached Accessory Building Application.
Sources & verification
Verified against official sources. Last reviewed 2026-07-03.
- City of Twin Falls Building Safety Department — official building department
- Residential Detached Accessory Building Application (PDF) | City of Twin Falls
- Permit Responsibilities and Requirements | City of Twin Falls
- Master City-Wide Fee Schedule (PDF) | City of Twin Falls
- Design Criteria: Residential | City of Twin Falls
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 Twin Falls building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.
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