ADU rules in West Allis, WI — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
West Allis regulates accessory buildings under Chapter 19 (Zoning) of the Revised Municipal Code, adopted under the city zoning authority of Wis. Stat. Sec. 62.23. Sec. 19.42 (Residential Accessory Buildings) caps detached accessory structures at 50% of the principal building area, not to exceed 800 square feet, with a maximum exterior wall height of 20 feet. Setback minimums include 10 feet from the principal building, 3 feet from side lot lines, and 3-5 feet from rear lot lines depending on alley adjacency. The West Allis Zoning Code does not establish a separate by-right accessory dwelling unit (ADU) class in the manner of cities like Appleton; a habitable second dwelling unit on a single-family lot generally requires zoning interpretation by the Planning and Zoning Department.
Chapter 19 of the West Allis Revised Municipal Code is the city's Zoning Ordinance, organized into Subchapter I (Administration), Subchapter II (Districts), Subchapter III (Uses), Subchapter IV (Structures), and Subchapter V (Planned Development). Sec. 19.42 (Residential Accessory Buildings) provides the dimensional standards that govern garages, sheds, and similar detached accessory structures on residential lots. The ordinance limits detached accessory building coverage to 50% of the principal building footprint, capped at 800 square feet, and limits the maximum exterior wall height to 20 feet (with overall height not exceeding the height of the principal building or 20 feet, whichever is less). Required setbacks under Sec. 19.42 include a minimum 10-foot separation from the principal building, a 60-foot minimum front setback, a 3-foot minimum side setback, and a rear setback of 5 feet when the lot abuts an alley or 3 feet when it does not. West Allis zoning is administered by the Department of Building Inspections and Neighborhood Services and the Plan Commission. Property owners considering a habitable accessory structure intended as a second dwelling should confirm with the Planning and Zoning Department (414-302-8460) whether the proposal is permitted, requires a conditional use, or requires a zoning text amendment, and should obtain building permits before construction.
Constructing an accessory building that exceeds the size, height, or setback limits of Sec. 19.42, or occupying an accessory structure as a separate dwelling unit without zoning approval, violates Chapter 19 of the West Allis Revised Municipal Code. Enforcement may include stop-work orders, daily forfeitures under the city's general penalty provisions, and orders to remove or modify nonconforming construction. Permits and inspections are administered by Building Inspections and Neighborhood Services.
West Allis, WI
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West Allis, WI
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West Allis, WI
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West Allis, WI
RV and recreational vehicle parking in West Allis residential areas is governed by city zoning code. Generally one RV per lot is permitted with setback requi...
West Allis, WI
Large commercial vehicles are restricted in West Allis residential zones under city zoning code. Contact West Allis Code Enforcement for specific requirements.
West Allis, WI
West Allis requires vehicles parked on improved surfaces. Front lawn parking prohibited. Driveway modifications require permits.
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