Rock County, WI Accessory Structures: Shed & Carport Rules (2026)
Shed permit rules in Rock County, WI, also referred to as storage shed, backyard shed, or accessory building regulations, set size limits, setbacks, and when a building permit is required.
Key Facts
- Accessory side setback (Town of Union A-1)
- 10 ft each side
- Max building height (A-1)
- 35 ft
- Principal building first
- Required before accessory
- Rule source
- Town zoning under 59.69
- Standards
- Vary by town and district
Summary
In Rock County's unincorporated towns, accessory buildings like sheds must meet the district's yard setbacks. In the Town of Union's A-1 district, accessory buildings need a 10-foot side setback and buildings top out at 35 feet.
Minimum Side Yard Setback: Principal Buildings 20 ft. on each side; Accessory Buildings 10 ft. on each side. Maximum Building Height 35 ft.
Full Breakdown
Sheds and detached garages are 'accessory buildings' governed by the zoning of your town, village or city. In towns that adopted county zoning, Wis. Stat. 59.69 lets the county regulate the location, height and setback of buildings. Standards vary by district. Example from the Town of Union (Rock County) A-1 zoning ordinance dimensional table below. Most towns also require the principal home to exist before an accessory structure is built, and many require a zoning permit for structures over a set square footage. Verify size thresholds and setbacks with your town clerk or the county PECD office.
Violations & Fines
A shed placed inside a required setback or built without a permit may have to be moved or removed, plus zoning forfeitures set by the local ordinance.
Frequently Asked Questions
How close to my lot line can a shed go?
Do I need a permit for a small shed?
Sources & Official References
Other rules in Rock County
How Rock County compares: Shed Permit Requirements by City·Compare Rock County to another location·View the Wisconsin accessory structures overview
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