Accessory Structures in Idaho Falls, ID (2026)
5 verified accessory structures rules for Idaho Falls, Idaho, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Idaho Falls allows accessory dwelling units in low-density (RP, R1) and medium-density (RMH) residential zones under Title 11 of the Municipal Code. ADUs are capped at 750 square feet, require owner-occupancy of one unit on the lot, and must provide one additional parking space.
Idaho Falls Accessory Dwelling Units (ADUs)
Some RestrictionsShed Rules
In Idaho Falls, any detached structure over 120 square feet that houses property, equipment, or people needs a building permit. Even permit-exempt sheds must meet Title 11 zoning setbacks, including a three-foot rear yard in residential zones, and accessory buildings cannot cover more than 30% of the rear yard.
Idaho Falls Shed Rules
Some RestrictionsGarage Conversions
Idaho Falls does not allow a garage to be converted into an accessory dwelling unit unless the required off-street parking is provided elsewhere on the lot. Any habitable conversion must meet Title 11 zoning, parking minimums, and city building permit requirements.
Idaho Falls Garage Conversions
Some RestrictionsCarport Rules
Carports and patio covers in Idaho Falls require a building permit because of eastern Idaho's snow and wind loads. As accessory structures they must also satisfy Title 11 zoning setbacks and keep front, rear, and side yards open and unobstructed.
Idaho Falls Carport Rules
Some RestrictionsTiny Homes
Idaho Falls has no separate tiny-home category; a permanent tiny house on a foundation is treated as a dwelling and a backyard tiny home is treated as an accessory dwelling unit, capped at 750 square feet in RP, R1, and RMH zones. RVs and recreational-vehicle tiny homes cannot be used as dwellings.