Sauk County, WI Accessory Structures: ADU Impact Fees (2026)

Sauk County's zoning ordinance has no development-impact-fee schedule tied to an accessory dwelling. What Sauk County Code § 7.059 imposes instead is a recurring compliance cost on the owner of an approved temporary secondary dwelling for a dependency living arrangement or farm use. Section 7.059(2) requires the owner to submit an affidavit to the Zoning Administrator every three years confirming the continuing need for the unit, and Section 7.059(7) requires the owner to pay an inspection fee, set by the Land Resources and Environment agency, to the Zoning Administrator every three years by June 1 of the third year.

Both obligations run for as long as the temporary secondary dwelling remains in use; when the arrangement ends, the property owner must notify the Zoning Administrator, and within 30 days either the dwelling is removed or a new land use permit converts it to an accessory structure. Because the permit issued under this section is not transferable, a buyer of the property cannot simply inherit the existing secondary-dwelling approval; the fee and affidavit cycle, and the underlying eligibility test for a dependency arrangement or qualifying farm operation, effectively resets with any change in use or ownership.

The fee amount itself is set administratively by the agency rather than fixed in the ordinance text, so the current dollar figure should be confirmed with the Zoning Administrator's office before budgeting for a renewal.