Wausau, WI Accessory Structures: ADU Rules (2026)

28(6) as either a residential dwelling located above the ground floor of an office, commercial, or institutional building, or a residential unit on the same lot as a single-family dwelling, whether built into the same structure or in a detached building. Four baseline regulations apply regardless of configuration. First, occupancy is capped: the number of occupants of the accessory dwelling unit shall not exceed one family plus one roomer, or two unrelated individuals, keeping the unit at a small-household scale. Second, additional entrances cannot be added to the front elevation of an existing building, though side, rear, or street-side elevations remain open for a new entry, preserving the street-facing look of a single-family home.

Third, the unit must adhere to the setback requirements and standards for the underlying zoning district, so an ADU in an SR-2 or SR-5 lot follows that district's dimensional table rather than a separate ADU-specific setback. Fourth, where an ADU entryway sits in a rear or side yard, it must connect to a street frontage by a paved walkway or driveway, ensuring safe, all-weather access rather than a dirt path across the yard. 32 is required before one can be built or converted, even where the four baseline standards above are otherwise met.