Before you get quotes
Madison requires guards around any deck more than 2 feet above ground, at least three feet high. Stairs with more than three risers need a handrail, with a guard that stops a 4 3/8-inch ball on every open side. Sun Prairie points deck builders to the state code’s stair, handrail and guard section, SPS 321.04.
- Deck height above grade
- Guard height of three feet or more
- Stair handrails past three risers
- Baluster spacing
Sources: Wisconsin Uniform Dwelling Code, SPS 325 Appendix B · City of Madison Development Services Center, Decks. Checked November 9, 2026. Confirm current requirements with your building inspector.
Near Madison
Price check
See the Madison deck cost guide for 2026 published price ranges and permit fees from Madison and Verona.
Related
Questions about deck guards & railings
Are you the deck builder?
An independent builder you hire directly. This is a Madison-area referral site, so we pass your request along; we do not build, price or guarantee anything.
When does Madison require a guard?
On any deck more than 2 feet above ground, at least three feet high.
What opening is allowed in a stair guard?
It must stop a 4 3/8-inch ball, per the city’s deck page.
Is a permit needed?
In Madison, yes: the city says you need a permit to build a deck. Fitchburg requires one for decks 24 inches or more above grade, Sun Prairie wants a drawing and site plan, and Verona lists a $300 deck permit. Each Dane County community sets its own rules.