Sun Prairie deck permit
Sun Prairie asks for a building permit application, a drawing that follows one of three accepted construction methods, and a site plan. Decks up to 3 feet high may come within 8 feet of the rear property line; taller decks must stay 24 feet back. A roof over the deck means larger setbacks, and a pergola needs a permit only if it is attached to a building.
Sources: City of Sun Prairie Building Inspection, Decks, Gazebos & Pergolas · Wisconsin Uniform Dwelling Code, SPS 325 Appendix B. Checked November 9, 2026. Confirm current requirements with your building inspector.
Composite Decks in Sun Prairie
Composite in Wisconsin has to carry a label showing ASTM D7032 compliance under the state deck appendix. The frame under composite is usually wood, so ask how the builder protects the joist tops and ledger from water. Madison’s own deck page reminds owners to use weather-resistant materials such as treated lumber.
Tell the builder which board line you like and ask what joist spacing it needs.
Sources: Wisconsin Uniform Dwelling Code, SPS 325 Appendix B. Checked November 9, 2026. Confirm current requirements with your building inspector.
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FAQ
Is a permit needed for composite decks in Sun Prairie?
Sun Prairie asks for a building permit application, a drawing that follows one of three accepted construction methods, and a site plan. Decks up to 3 feet high may come within 8 feet of the rear property line; taller decks must stay 24 feet back. A roof over the deck means larger setbacks, and a pergola needs a permit only if it is attached to a building.
What is a typical price?
Mid-grade composite runs $45 to $65 per square foot installed in Wisconsin, per the Wisconsin Homeowners Guide. That is a published estimate, not a quote.
Who does the work?
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.