What Permits Do You Need to Build a Deck in Wisconsin?
Everything you need to know about deck permits in Wisconsin, including when a permit is required, typical costs, footing depth requirements, and inspection steps.
Yes, you typically need a permit. To build a deck in most Wisconsin municipalities, you need a Deck Permit. Here's exactly what's required.
Permits Required
The following permits are typically required to build a deck in Wisconsin. Actual requirements vary by municipality.
Deck Permit
Required for constructing new decks, porches, and exterior elevated platforms in Wisconsin. The state regulates decks under the Uniform Dwelling Code with specific requirements for footings below the frost line (48 inches in most of Wisconsin), ledger board attachment, railing height, and structural connections per SPS 320–325.
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:
- Deck Permit: Ground-level patios (pavers or concrete at grade)
- Deck Permit: Small platforms under 200 sq ft and under 30 inches in some municipalities
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 for a small deck in Wisconsin?
In most Wisconsin municipalities, yes. Any deck more than 30 inches above grade requires a permit statewide under the Uniform Dwelling Code. Even ground-level decks may require permits depending on your city — Milwaukee and Madison require permits for all attached decks regardless of height. Ground-level patios made from pavers or poured concrete at grade are generally exempt.
How deep do deck footings need to be in Wisconsin?
Deck footings in Wisconsin must extend at least 48 inches below grade in most of the state to get below the frost line. Some southern counties allow 42 inches. Pre-cast pier blocks sitting on the ground surface do not meet code for attached or elevated decks. Your footing size and depth will be verified during the footing inspection.
How much does a deck permit cost in Wisconsin?
Deck permits in Wisconsin typically cost $75 to $600, depending on the municipality and deck size. Milwaukee charges around $150–$350 for most residential decks. Madison ranges from $100 to $400. Smaller cities often charge $75 to $200. You will need to submit a site plan and construction drawings with your application.
Building in multiple cities?
See permit requirements for any Wisconsin municipality instantly. Compare fees, timelines, and processes side by side across your active jurisdictions.