Minnehaha County, SD Accessory Structures: Garage Conversions (2026)

Minnehaha County's Planning & Zoning Department reviews garage-to-living-space conversions case by case. Under SDCL Chapter 11-2, the county has broad authority to require that any change of use — including converting an attached or detached garage to habitable space — comply with the zoning district's density, parking, setback, and use regulations. Key considerations: (1) A converted garage typically must satisfy the same minimum off-street parking requirement as the original dwelling (the conversion may eliminate required parking and trigger a need to add a replacement garage or driveway). (2) If the conversion creates a separate dwelling unit (kitchen, bath, sleeping area, separate entrance), it is classified as an accessory dwelling unit (ADU) and must satisfy any ADU-specific rules in the county zoning ordinance. South Dakota has no statewide ADU mandate (contrast California, Colorado, Maine), so Minnehaha County's local rules govern entirely. (3) Even without zoning concerns, building, electrical, mechanical, and plumbing permits are required for the construction work itself — the county Planning & Zoning Department or its delegated building official administers these. (4) On-site wastewater (septic) sizing is governed by the Minnehaha County On-Site Wastewater Regulations, and adding habitable bedrooms may require a septic upgrade. Cities within the county (Sioux Falls, Brandon, etc.) have their own separate conversion rules; this entry covers only unincorporated county areas.