Sioux Falls, SD Accessory Structures: ADU Permits (2026)

An ADU in Sioux Falls is permitted as an accessory use under § 160.093 and does not require a conditional use or special use permit within the city limits — it is built under a standard residential building permit issued by the City of Sioux Falls Building Services Division (231 N. Dakota Avenue). Permit fees are computed from the construction valuation per the city's adopted Building Permit Valuation/Fee Schedule (most recently the 2023 schedule). The ADU must comply with the 2021 International Residential Code as adopted by Sioux Falls in Title 50 (Buildings and Construction), including R-2 or R-3 occupancy provisions, separate egress, smoke and carbon monoxide alarms (the latter required statewide under SDCL Chapter 34-45), and minimum room sizes. A certificate of occupancy under § 160.726 is required before the ADU may be occupied. Plan review is administered by Building Services and typically does not require Planning Commission or City Council action because ADUs are a by-right accessory use, not a conditional use, in eligible residential districts. Outside city limits but within the joint zoning area, the Joint Zoning Ordinance requires a conditional use permit and proof of wastewater capacity (§ 159.305).