Accessory Structures in Marathon County, WI (2026)
2 county-level rules, plus city-specific rules for 2 cities in Marathon County, Wisconsin.
Verified from official government sources
ADU Rules
Marathon County zoning flatly bars using a detached garage, shed, or other accessory building as a separate dwelling unit, and residential lots are capped at one house anyway.
Marathon County Bans ADUs in Accessory Buildings
Heavy RestrictionsMarathon County Code § 17.401.02.B
Detached Accessory Buildings. Detached accessory buildings shall not be used as a separate dwelling unit and shall comply with the requirements of the following Table 6.C.Accessory Structures Housing Livestock. Section 17.204.01.A.3.D.Accessory Structures within shoreland jurisdiction. Existing and new accessory buildings shall comply with all Marathon County shoreland regulations and provision...
Shed & Carport Rules
Detached sheds and garages in Marathon County's Urban Residential district top out at 1,400 square feet, need a 15-foot gap from the house, and must sit at least 7 feet off side and rear lines.
Marathon County Shed Size and Setback Rules
Some RestrictionsMarathon County Code § 17.401.02, Table 6
Table 6: DETACHED ACCESSORY BUILDING STANDARDS. Setback Requirements from principal structure 15 feet... from side property line 7 feet [U-R, L-D-R, R-R, R-E, G-A/F-P]... Maximum Size 1,400 sq.ft. [U-R], 2,000 sq.ft. [L-D-R and RR], NONE [R-E, G-A/F-P]. Maximum Height 24 feet [U-R, L-D-R], 35 feet [R-E, G-A/F-P].
Accessory Structures by City in Marathon County
2 cities in Marathon County have their own accessory structures rules. Each link goes to that city's dedicated page with code citations.
All Marathon County ordinances
See every category we cover for Marathon County: parking, noise, fences, fires, animals, pools, and more.
Marathon County Ordinance Hub →