ADU rules in Mitchell

Mitchell's zoning title (City Code Title 10) has no accessory dwelling unit, guest house or second-dwelling use: American Legal searches of the whole code for 'accessory dwelling', 'guest house', 'second dwelling' and 'accessory apartment' return zero hits. The residential accessory building list in Sec. 10-4-5(D)(1) is limited to garages, carports, sheds, garden houses, gazebos, pergolas, greenhouses, pet shelters, pools, courts and boathouses, and Sec. 10-4-5(G)(3) bars 'more than one main building on a lot'. A backyard cottage or garage apartment with its own kitchen would therefore be a second principal dwelling, which no residential district allows; the only lawful second unit is inside or attached to the house as a two-family dwelling (see attachedAllowed).

There is no attached or internal ADU category either, but a second unit inside or attached to a house is lawful as a two-family dwelling where the district allows one. A 'dwelling unit' is separate living quarters 'with cooking, sleeping, and sanitary facilities' for one family (Sec. 10-2-2), so a basement or addition apartment turns the house into a two-family dwelling. Two-family dwellings are a permitted use in R-3 Medium Density Residential (Sec. 10-5D-2, on a lot of at least 9,000 sq ft and 75 ft wide) and fall within R-4 High Density Residential's permitted 'multi-family dwellings of twenty four (24) units or less' (Sec. 10-5E-2, with a two-unit row of 8,000 sq ft and 75 ft); they are a conditional use in R-2 (Sec. 10-5C-3) and are not listed at all in R-L or R-1, whose only dwelling use is single-family. R-5 lists multi-family dwellings of twelve units or less only as a conditional use.

Title 10 sets no size for an accessory dwelling because none exists, and it sets no floor-area cap for either unit of a two-family dwelling; the controls are the density tables in Secs. 10-5D-5 (R-3: one unit 6,000 sq ft and 60 ft wide, two units 9,000 sq ft and 75 ft, 25 ft front and rear yards, 3 ft side yards, 60 percent coverage, 2 1/2 stories or 35 ft) and 10-5E-5 (R-4: two units 8,000 sq ft and 75 ft, 75 percent coverage, 6 stories or 65 ft). For scale, accessory buildings may not exceed 2,000 sq ft in R-1, R-2 and R-5, or 2,000 sq ft per dwelling unit in R-3 and R-4, and no accessory building may exceed 22 ft in height; these caps are for garages and sheds, which may not be dwellings.

No ADU exists for an owner-occupancy rule to attach to, and the lawful way to add a unit, a two-family dwelling, is listed in R-3 (and within R-4's multi-family use) as a permitted use with no residency condition. American Legal searches for 'owner occupied' and 'owner-occupied' return zero hits across the whole City Code. The only owner-occupancy test in Title 10 is the bed and breakfast definition ('a private single-family residence occupied by the owners'). South Dakota has no state ADU owner-occupancy rule either way.

The Sec. 10-11A-3 schedule, which applies 'in all districts', requires for dwellings '1 parking space for each dwelling unit, plus 1 additional space for each 2 dwelling units in a building', so converting a house into a two-family dwelling raises the lot's requirement from 1 to 3 spaces. Under Sec. 10-11A-2(D) off-street spaces may sit in any required yard except the front yard, although a residence may use a front-yard driveway up to 24 ft wide for parking. Parking is one of the items the Board of Adjustment may vary (Sec. 10-3-3(B)).

It depends on the district. In R-3 (and R-4) a two-family dwelling is a permitted use, so a conversion or duplex needs only a building permit through Public Works (the city's Planning and Zoning page posts the Building Permit Application). In R-2 a two-family dwelling is a conditional use: the application goes to the Planning Commission for a noticed public hearing (mailed notice to owners within 140 ft and a newspaper notice), and the Board of Adjustment, which under Sec. 3-3-1 is the whole City Council with the mayor as chair, decides it on the Sec. 10-3-3(C) criteria with a two-thirds vote of its full membership. In R-L and R-1 no second unit is available without a rezoning, and a variance cannot add a use (Sec. 10-3-3(B)).

American Legal searches for 'short-term' and 'short term' find only the definitions section (outside commercial storage), and 'rental property', 'airbnb', 'owner occupied' and 'rental dwelling' return zero hits, so the City Code has neither a short-term rental regime nor a long-term rental licensing program. Title 10 does regulate two lodging uses: a bed and breakfast (an owner-occupied single-family residence offering 'temporary accommodations for a charge to the public') is a conditional use in R-2, R-3 and R-4, and a lodging house (a single-family unit with up to six guestrooms let 'pursuant to previous arrangement, but not open to the public or transients') is a conditional use in R-2 and R-3 and permitted in R-4. A whole dwelling rented nightly to the public falls outside both definitions, and the code is silent on it; at state level, a home rented in its entirety on a daily or weekly basis for more than fourteen days a year is a vacation home establishment licensed by the Department of Health (SDCL 34-18-1).