Deck Stair Code in Minnesota: Rise, Run and Handrails

Deck stair code in Minnesota

Short answer: Deck stairs must be at least 36 inches wide, with risers no taller than 7 3/4 inches and treads at least 10 inches deep. Stairs with four or more risers need a handrail 34 to 38 inches high. Decks and stairs more than 30 inches above grade need a guard at least 36 inches high, with gaps a 4-inch ball can't pass through.

Source: Bloomington, residential deck handout (PDF) · Golden Valley, decks handout (PDF). Checked November 4, 2026.

These numbers come from city deck handouts for the Minnesota Residential Code. Your city may add its own rules.

Drawn to scale. Stairs must also be at least 36 inches wide and lit at the landing. Numbers from Bloomington's and Golden Valley's deck handouts.

The rules, one by one

Part	Rule
Width	At least 36 inches
Riser height	7 3/4 inches at most (Bloomington: 4 inches at least)
Tread depth (run)	10 inches at least
Even steps	No riser or tread can be more than 3/8 inch bigger than the smallest one
Open risers	A 4-inch ball can't pass through (Bloomington: on stairs more than 30 inches above grade)
Handrail	Required with 4 or more risers. Top 34 to 38 inches above the tread nosings, easy to grip (round rails 1 1/4 to 2 inches), ends returned or ending in posts
Guard	On decks and stairs more than 30 inches above grade or a lower deck. At least 36 inches high (Golden Valley), and a 4-inch ball can't pass through
Under the stair guard	The triangle between riser, tread and bottom rail must stop a 6-inch ball
Light	A light at the landing, switched from inside the house or turned on automatically
Stringers	No more than 18 inches apart (Golden Valley; for composite, follow the maker)
Footings	Frost footings under stairs with 4 or more risers (Golden Valley)

Before you build

Stairs are part of the deck permit, and the inspector checks them at the final inspection. A deck more than 30 inches off the ground needs a permit in Minnesota. See the permit guide, check how deep your footings go, or find a deck builder near you.

Sources: Bloomington, residential deck handout (PDF) · Golden Valley, decks handout (PDF)

Questions

What is the maximum riser height for deck stairs in Minnesota?

7 3/4 inches. Bloomington also sets a minimum of 4 inches, and no riser can be more than 3/8 inch taller than the shortest one.

How deep do deck stair treads need to be?

At least 10 inches. No tread can be more than 3/8 inch deeper than the shallowest one.

When do deck stairs need a handrail?

When they have four or more risers. The top of the handrail goes 34 to 38 inches above the tread nosings, and it has to be easy to grip.

How tall does a deck railing need to be?

At least 36 inches on decks more than 30 inches above grade, with openings small enough that a 4-inch ball cannot pass through.

How wide do deck stairs need to be?

At least 36 inches.

Do deck stairs need lights?

Yes. Exterior stairs need a light at the landing, switched from inside the house or turned on automatically.