When you need a permit
Under the Minnesota State Building Code, a deck needs a building permit if:
- it is more than 30 inches above the ground, or
- it is attached to the house or another structure with frost footings.
Cities can add rules. St. Paul, for example, also requires a permit when the deck is the landing outside an exterior door, and decks more than 24 inches off the ground must meet zoning setbacks and lot coverage limits.
In the Twin Cities, deck footings must reach at least 42 inches below grade. That puts them below the frost line, so the ground can't heave the deck in winter. Freestanding decks and very low decks can have different rules, so ask your city.
Who pulls the permit
Normally the builder. Ask before you sign and make sure the permit is in the quote.
Check the builder's license
Minnesota requires a residential building contractor or remodeler license for contractors who do more than one kind of work for a homeowner, which covers most deck jobs. You can look up any license on the Department of Labor and Industry website. Ask for proof of insurance too.
Your city's rules
This guide is general information, not legal advice. Rules change, so confirm with your city before you build.
Sources: St. Paul, when is a permit required (PDF) · Minneapolis, decks and building permits (PDF) · Bloomington, residential deck handout (PDF) · Golden Valley, decks handout (PDF) · Minnesota DLI, residential contractor licensing