Twin Falls County, ID Accessory Structures: Shed & Carport Rules (2026)
Shed permit rules in Twin Falls County, ID, also referred to as storage shed, backyard shed, or accessory building regulations, set size limits, setbacks, and when a building permit is required.
Key Facts
- Lot coverage cap
- 35% of lot, shed plus house combined
- Side/rear setback
- 3 feet, or closer with recorded neighbor consent
- Corner lot setback
- 25 feet from side street line
- Eave clearance, accessory
- 12 inches from side or rear line
- Eave clearance, main house
- 30 inches from side or rear line
Summary
In the Agricultural Range Preservation zone of unincorporated Twin Falls County, a detached shed or other accessory building can sit as close as 3 feet to a side or rear property line, or 25 feet from a corner lot's side street line, but the shed plus the house together cannot cover more than 35% of the lot.
Detached accessory use buildings may be constructed on the rear yard area provided that such buildings plus the principal building shall not occupy more than thirty five percent (35%) of the total lot area nor be located closer than three feet (3') to a side or rear property line of an interior yard except by written, notarized and recorded permission of the adjoining property owner(s) and appropriate firewall construction, nor closer than twenty five feet (25') to the side street property line of a corner lot. ... ... A. Eaves projecting from main buildings shall not be closer than thirty inches (30") to a side or rear property line. B. Eaves projecting from accessory use buildings shall not be closer than twelve inches (12") to a side or rear property line.
Full Breakdown
Twin Falls County Code § 8-6A-6 governs detached accessory buildings, sheds, garages, storage buildings and similar structures, in the Agricultural Range Preservation (ARP) zone. The accessory building must sit in the rear yard area, and combined with the principal dwelling it cannot occupy more than 35 percent of the total lot area. The minimum setback from a side or rear interior property line is 3 feet, though a landowner can build closer with the adjoining property owner's written, notarized and recorded permission plus appropriate firewall construction between the structures.
On a corner lot, an accessory building cannot sit closer than 25 feet to the side street property line, the same setback the county requires of the principal building under § 8-6A-5. Section 8-6A-7 adds a separate eave rule: eaves on the main house cannot project closer than 30 inches to a side or rear property line, while eaves on an accessory building are held to a tighter 12-inch clearance. Off-street parking for any accessory use still has to meet Chapter 11's parking standards under § 8-6A-8.
Because these numbers are specific to the ARP zone, other zoning articles carry their own accessory-building section, such as § 8-6B-6 in the Agricultural zone, so a shed's exact setback and lot-coverage limit depends on which of the county's zoning districts covers the parcel; the Zoning Administrator's office confirms the applicable district before issuing a building or agricultural building permit.
Violations & Fines
Exceeding the 35 percent combined lot coverage, or building an accessory structure closer than 3 feet to a side or rear line, or 25 feet on a corner lot's side street line, without recorded neighbor permission and firewall construction violates § 8-6A-6. Twin Falls County Code § 1-4-1's general penalty applies: a fine up to $300 and up to six months in jail for each day the violation continues, plus court costs.
Frequently Asked Questions
How close to my property line can I build a shed in unincorporated Twin Falls County?
Is there a size limit on how much of my lot a shed can cover?
Do shed eaves have their own setback?
Sources & Official References
Other rules in Twin Falls County
How Twin Falls County compares: Shed Permit Requirements by City·Compare Twin Falls County to another location·View the Idaho accessory structures overview
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