What Permits Do You Need to Build an Accessory Structure in Wisconsin?
Guide to accessory structure permits in Wisconsin, covering sheds, barns, workshops, and other outbuildings, including size thresholds, setback rules, and when permits are required.
Yes, you typically need a permit. To build an accessory structure in most Wisconsin municipalities, you need a Accessory Structure Permit. Here's exactly what's required.
Permits Required
The following permits are typically required to build an accessory structure in Wisconsin. Actual requirements vary by municipality.
Accessory Structure Permit
Required for detached structures such as sheds, workshops, barns, and outbuildings on residential or commercial property. Wisconsin municipalities set size thresholds — structures under 200 sq ft are often exempt, but thresholds vary. Larger accessory structures must comply with setback, height, and lot coverage requirements.
Inspection required after work is completed.
Where to Apply
Permit requirements, fees, and processing times vary by municipality. Check the specific requirements for your location:
Browse all jurisdictions →Exemptions & Special Cases
In some circumstances, a permit may not be required. Common exemptions include:
- Accessory Structure Permit: Sheds under 200 sq ft without electrical or plumbing in most municipalities
- Accessory Structure Permit: Portable storage units and temporary structures
Exemptions vary by municipality. Always confirm with your local building department before starting work without a permit.
Frequently Asked Questions
Do I need a permit to build a shed in Wisconsin?
It depends on the size and your municipality. Many Wisconsin cities exempt accessory structures under 120 to 200 square feet from a building permit, but you may still need to comply with zoning setback requirements. Structures with electrical wiring always require an electrical permit regardless of size. Some cities require a zoning permit even for small sheds to verify setback compliance. Always check your local code.
How big can I build a shed without a permit in Wisconsin?
The permit-exempt size threshold varies by municipality. Milwaukee exempts accessory structures under 120 square feet. Madison exempts structures under 200 square feet. Many cities use 120 or 150 square feet as the cutoff. Even when exempt from a building permit, the structure must still comply with zoning requirements including setbacks, height limits, and lot coverage maximums.
What are the setback requirements for accessory structures in Wisconsin?
Setback requirements for accessory structures (sheds, workshops, barns) are set by each municipality's zoning code. Common setbacks are 3 to 5 feet from side and rear property lines. Front yard placement of accessory structures is usually prohibited. Maximum height is typically 15 to 20 feet for detached accessory structures. Total lot coverage (all structures combined) is usually limited to 30–40% of the lot area.
Building in multiple cities?
See permit requirements for any Wisconsin municipality instantly. Compare fees, timelines, and processes side by side across your active jurisdictions.