Portage County, WI Accessory Structures: Shed & Carport Rules (2026)

Sec. 7.1.2(1)(b)4 of the Portage County Zoning ordinance governs accessory buildings, including private garages, in the R2 Single Family Residence District, and no accessory building may be used as a separate dwelling unit. Square footage is calculated from the outside dimensions of all detached garage space and similar detached structures combined. The maximum cumulative total is 2,800 square feet on lots smaller than two acres and 3,200 square feet on lots two acres or larger. The Planning and Zoning Department may require increased screening or larger setbacks for any accessory building exceeding 2,000 square feet.

Design standards require that a structure's length not exceed twice its width, that its maximum height at the roof peak stay at or under 20 feet, and that its design and color complement the residence; no commercial activity may be conducted out of an accessory building. Special exception review by the Board of Adjustment is required if an accessory building exceeds the maximum square footage or otherwise fails to meet these provisions, per Sec. 7.1.2(1)(c). Larger accessory buildings also trigger a separate stormwater control plan requirement, covered on this site's stormwater page. A Zoning Permit from the Planning and Zoning Department is required before construction begins in any case.