The process to adopt or amend a general zoning ordinance is outlined in state statutes and summarized below:¹

1. Petition to adopt or amend the zoning ordinance. The plan commission prepares draft zoning ordinance recommendations, usually with the assistance of legal counsel, an advisory group, zoning staff, or a private consulting firm. A petition to amend the zoning ordinance may be made by a local landowner, the plan commission, or the governing body.
2. Public notice. The clerk publishes a class 2 notice in the community’s official newspaper and mails notice to parties in interest. If the proposed ordinance or amendment has the effect of changing the allowable use of the property, the notice must include a map or description of the property affected by the ordinance and a statement identifying where the map may be obtained.
3. Public hearing. The plan commission, governing body or other appropriate body holds a public hearing on the draft zoning ordinance or amendment.² When making significant changes to an ordinance, opportunities for public participation prior to the public hearing are recommended to ensure that the ordinance is understood and accepted by the public.
4. Plan commission recommendation. In response to public comments, the plan commission may modify the draft zoning ordinance or forward it to the governing body with a recommendation for action.³
5. Governing body decision. The governing body may approve, modify or deny the proposal, or return it to the plan commission with directions to make additional changes. If the proposal is substantially changed, the public hearing process should be repeated.⁴ In most cases, a majority vote of the governing body is needed to adopt the ordinance.⁵ However, an affirmative vote of three-fourths of the governing body is required if landowners opposing the amendment file a valid protest petition.⁶ Likewise, an affirmative vote of two-thirds of the governing body is required if the owner or operator of an affected airport files a protest petition⁷ or if the mayor or county executive vetoes the zoning amendment.⁸
6. Publication of ordinance and effective date. Adopted ordinances and amendments must be published as a class 1 notice and take effect on the day after publication unless otherwise prescribed.⁹ County zoning ordinances and amendments take effect once approved by the town board and county executive.

¹See Wis. Stat. §§ 59.69(5) counties; 60.61(4) towns; 62.23(7)(d) cities, villages, towns with village powers.
²In municipalities, the public hearing may be held by the governing body, plan commission, or board of public land commissioners (Wis. Stat. § 62.23(7)(d)1). In counties, the public hearing may be held by the county zoning agency (planning & zoning committee or plan commission) or the county board (Wis. Stat. §§ 59.69(5) and (6)).
³If the governing body of a municipality does not receive a report from the plan commission within sixty days, it may proceed without it (Wis. Stat. 62.23(7)(d)2).
⁴A “substantial change” is one that alters the fundamental character of the original proposal such that it changes the group affected by the proposal or the impact on that group. Herdeman v. City of Muskego, 116 Wis. 2d 687, 690,343, N.W.2d 814 (Ct. App. 1983).
⁵Majority means a majority of all members of the city council, village board or town board (Wis. Stat. §§ 62.11(3)(b), 62.23, 61.35 and 60.62) or a majority of county board members present, unless otherwise provided by law (Wis. Stat. § 59.02).
⁶For cities, villages and towns with village powers, the protest must be signed by owners of 20% of the land to be altered, or by owners of 20% of land within 100 feet, or by owners of 20% of land extending 100 feet opposite the street frontage (Wis. Stat. § 62.23(7)(d)2m).For counties and towns without village powers, the protest must be signed and acknowledged by owners of 50% of the land to be altered, or by owners of 50% of the land within 300 feet (Wis. Stat. §§ 59.69(5)(e)5g and 60.61(4)(c)2). County protest petitions must be received by the clerk at least 24 hours prior to the meeting of the county board.
⁷Wis. Stat. 59.69(5)(e)5m, 60.61(4)(c)2, 62.23(7)(d)2m.b.
⁸Wis. Stat. §§ 59.17(6) and 62.09(8)(c).
⁹Wis. Stat. §§ 59.14, 60.80, 61.50, and 62.11(4).

Advance notice of a hearing to adopt or amend a zoning ordinance must be provided to the following parties:

• News media. Notice must be provided in writing or by phone, fax or email to any news media that have filed a written request. Notice must also be provided to the government unit’s official newspaper, or if there is no official newspaper, to other media likely to give notice in the affected area.¹
• Adjacent municipalities. Notice of county zoning amendments must be mailed to the clerk of affected towns at least 10 days prior to the hearing.² Written notice of the adoption or amendment of a city, village or town zoning ordinance must be provided to the clerk of any municipality located within 1,000 feet of lands affected by the ordinance at least 10 days prior to the hearing.³
• Property owners. Notice of zoning ordinance adoption and amendment must be provided to property owners that have submitted a written request to receive notice of action affecting their property. Notice may be provided by mail or other agreed upon method, and an appropriate fee may be charged.⁴
• Airport owners. Notice of a zoning amendment in an airport affected area must be mailed to the owner or operator of the airport. The airport affected area extends three miles from the boundary of a public airport unless otherwise agreed.⁵
• Military installations. Written notice of city, village and town zoning ordinance adoption and amendment must be provided to the commanding officer of a military base or installation with at least 200 assigned military personnel or at least 2,000 acres, located in or near the municipality.⁶
• Department of Natural Resources. Written notice of amendments to shoreland, shoreland-wetland, and floodplain zoning ordinances must be provided to the appropriate local DNR office at least 10 days prior to the hearing.⁷
• Department of Agriculture, Trade and Consumer Protection. Written notice of amendments to farmland preservation zoning must be provided to DATCP. This requirement does not apply when land is rezoned out of farmland preservation zoning.⁸

¹Wis. Stat. § 19.84.
²Wis. Stat. § 59.69(5) (e)2.
³Wis. Stat. §§ 62.23(7)(d)1.a & 2.
⁴Wis. Stat. § 59.69(5)(f) and 62.23(7)(d)4.
⁵Wis. Stat. §§ 59.69(5)(e)2, 60.61(4)(c)1, 62.23(7)(d)2, 62.23(6)(am)1.b and 66.1009.
⁶Wis. Stat. §§ 62.23(7)(d)1.a & 2.
⁷Wis. Admin. Code §§ NR 115.05(4)(h) & NR 116.20(2)(c).
⁸Wis. Stat. § 91.36(8)(d).