Rochester deck guide: permits, footings and loads (2026)

Updated October 29, 2026. This is general information, not legal or engineering advice. Confirm current requirements with the permit office for your address.

At a glance

When is a deck permit required in Rochester?

The City of Rochester's residential deck handout (revised January 2022, based on the 2020 Minnesota Residential Code) says a building permit is required for all decks attached to the home, and for freestanding decks 30 inches or more above grade with supporting beams, joists or posts. Applications are made online through the city's CitizenAccess portal. Fees are based on the valuation of the work, and for do-it-yourself projects the valuation is double the cost of materials.

What about the rest of Olmsted County?

Olmsted County Planning's deck and porch supplement says a building permit is required to build a deck that's attached to a structure or more than 30 inches above grade. Its submittal list includes a signed application, a certificate of survey or scaled site plan with distances to property lines, and two sets of scaled plans showing footing size and depth, post size and spacing, beam and joist sizes, stair location, an elevation with guard design, and decking type. County inspections are footing, framing (only when joists are lower than five feet above grade) and final, scheduled at least a day ahead at 507-328-7100. Cities such as Byron, Stewartville, Oronoco and Pine Island have their own arrangements, so confirm which office covers your address.

How deep do deck footings go?

Minnesota Rule 1303.1600 divides the state into two frost zones: five feet in Zone I in the north and 3½ feet in Zone II, which includes Olmsted County. Both the city handout and the county supplement put it as a 42-inch minimum, measured from the bottom of the footing to grade (the county says to undisturbed soil, measured vertically or horizontally). The city inspects footing holes after they're dug and before concrete is placed.

What loads does a deck have to carry?

The city handout says decks must be designed for a live load of at least 40 pounds per square foot, with a dead load of at least 10 psf assumed. For roofs, Minnesota Rule 1303.1700 sets the ground snow load at 50 psf in Olmsted County and the other southern counties, and 60 psf in a list of northern counties. A roof added later can overload a deck that was only built for people and furniture.

How should the deck attach to the house?

Per the city handout, ledger boards need at least ½-inch by 5-inch lag screws or bolts with washers, plus corrosion-resistant flashing. The county supplement adds that toenails or nails subject to withdrawal can't be used, that fasteners must be hot-dipped galvanized or stainless steel, that lag screw tips must extend past the inside face of the band joist, and that ledgers are flashed per code section R703.4.

Railings, stairs, outlets and power lines

• Guards at least 36 inches tall on decks more than 30 inches above grade, with openings that won't pass a 4-inch sphere (city handout)
• Guards able to resist 200 pounds of applied force (county supplement)
• A GFCI weatherproof receptacle on decks over 20 square feet with access from inside the home (city handout)
• At least 10 feet of clearance between the deck and overhead power lines (city handout)

Does Minnesota license deck builders?

The Minnesota Department of Labor and Industry requires a residential building contractor or remodeler license for anyone who contracts directly with an owner of a one- to four-unit home to provide work in more than one special skill. The eight special skills include carpentry, masonry and concrete, and exterior finishing, so a contractor who both pours a deck's footings and frames it is likely to need a license; DLI can confirm for a specific business. Contractors with gross annual residential receipts under $15,000 can work under a certificate of exemption instead. Contractors who hold the license pay into the state's Contractor Recovery Fund, which allows homeowners to file claims in certain cases. Check any contractor's status on the DLI license lookup.

What does the climate do to a deck?

Rochester averages roughly 35 inches of precipitation and 53 inches of snow a year, with a January mean of 14.7°F and records of 108°F and −42°F. Wood decks go through repeated wetting, freezing and drying, which opens checks in boards, loosens fasteners and rots ledgers that lack flashing. The city has also had damaging tornadoes on the northwest side in June 2010 and in southwest Rochester in June 2019.

Call before you dig

The city handout says to contact Gopher State One Call at least two full business days before digging, at 1-800-252-1166 (or 811). Footing holes often go right where gas, electric or communication lines run to the house.

Questions to ask a contractor

• What is your Minnesota DLI license number?
• Will you pull the permit, and with which office: the city, the county or another town?
• How deep and wide will the footings be, and when is the footing inspection?
• How will the ledger be fastened and flashed, or will the deck be freestanding?
• If I want a roof later, can the footings and beam be sized for it now?
• What does your warranty cover, and what do the board and railing warranties cover?

Sources

• City of Rochester: Residential deck requirements handout (rev. 01/2022)
• Olmsted County Planning: Residential decks and porches supplement
• Minnesota Rules 1303.1600: Footing depth for frost protection
• Minnesota Rules 1303.1700: Ground snow load
• Minnesota Department of Labor and Industry: Residential contractor licensing
• Wikipedia: Rochester, Minnesota
• Wikipedia: Byron, Minnesota
• Wikipedia: Stewartville, Minnesota
• Wikipedia: Pine Island, Minnesota
• Wikipedia: Oronoco, Minnesota