WI SB473

Requires all Wisconsin political subdivisions with zoning ordinances to allow at least one accessory dwelling unit (ADU) as a permitted use on any residential or mixed-use parcel with an existing single-family home, eliminating the need for conditional use permits, variances, or special approvals

Defines ADU as a residential unit on the same parcel as a single-family home that provides complete independent living facilities with a separate entrance, and may be within, attached to, or detached from the main dwelling or created by converting an existing structure

Permits local governments to impose certain restrictions: limiting ADU size to no larger than the existing home's square footage, enforcing maximum height limits (except for conversions of existing nonconforming structures), and requiring compliance with setback and lot coverage rules

Allows municipalities to prohibit newly created ADUs from being used as short-term rentals after the bill's effective date

Takes effect on the first day of the 7th month following publication