Pocatello, ID Accessory Structures: ADU Rules (2026)

Pocatello permits accessory dwelling units by right, not through a discretionary permit, wherever the underlying zoning already allows them. Section 17.06.100.B extends the use to all residential, commercial, and mixed-use districts, provided the standards of the section are met; where the ADU rules conflict with other Title 17 standards, the more restrictive standard controls. An accessory residential unit can be built inside or added onto an existing detached single-family home, or as a separate accessory structure on the same lot, and must function as a complete independent living facility with its own kitchen, bathroom, and sleeping area.

Only one ADU is allowed per single-family lot, and the lot must already meet the minimum lot size of its residential district; § 17.06.100.C.2 specifies that ADUs are not counted in density calculations, so adding one does not push a lot over its base density limit. Size is capped at 750 square feet with no more than one bedroom or sleeping room under § 17.06.100.C.3. Parking follows a sliding scale in § 17.06.100.C.4: if on-street parking is available and the primary home already meets its own off-street parking requirement, only one additional off-street space is required for the ADU; if on-street parking is not available for the primary structure, two off-street spaces must be provided for the ADU instead.

Height is capped at whichever is less: the height of the main structure or the limit set by the underlying zoning district. Detached ADUs need a walkway at least three feet wide, finished with a hard, all-weather surface, connecting the unit to the street the primary dwelling fronts, and exterior materials, siding, roofing, paint colors, and trim must match the primary dwelling unless an alternate design is justified.