Olmsted County, MN Accessory Structures: Shed & Carport Rules (2026)

22 of the Zoning Ordinance sets the accessory-building rules that govern sheds, detached garages and similar structures. No accessory building may go up before the principal building exists on the lot, and outside the R-1, ARC, RSD and non-farm A-4 areas it must sit within the buildable area of the lot. In the R-1, ARC and RSD districts an accessory building placed in the rear yard must clear at least 5 feet from an interior side lot line and 8 feet from a rear lot line, and the cumulative gross floor area of all accessory structures on the lot (measured on the largest floor, including any interior parking space) is scaled to lot size: 1,000 square feet under one acre, 1,200 square feet on one to two acres, and 1,500 square feet at two acres or more.

In the R-2 District the side or rear setback drops to 2 feet, but no accessory building anywhere may occupy more than 25 percent of the buildable area or rear yard, and none may sit closer to a right-of-way than the district's front or side-street yard line allows. Height is capped at 15 feet in the R-1, R-2 and ARC districts and on residential parcels in the RSD district. 00) carries out through the Rochester-Olmsted Planning Department, confirming the structure conforms to the ordinance. 04, and inside the cities of Rochester, Stewartville, Byron and the others, the city's own code applies instead.