Basement finishing in Minneapolis–St. Paul

Updated October 2026 · 4 public sources cited

Twin Cities basements are old: the median home in Minneapolis was built in 1951 and in St. Paul in 1952.¹ Minneapolis's basement finish guide is written for exactly those houses, with rules for low ceilings and old stairs that decide whether a room can legally be a bedroom.²

Habitable or not: the 6'4" rule

Minneapolis says bedrooms, other habitable rooms and the exit path to the stairs or outside door need a ceiling height of at least 6 feet 4 inches, measured to the lowest projection, including beams, girders and ducts. In an existing basement where 6'4" can't be reached, the space is considered non-habitable. It can still be finished, just not as a bedroom or living space.²

Habitable rooms must be at least 70 square feet and at least 7 feet in every horizontal direction.²

Adding a bedroom

• Egress: an exterior door or an egress window with at least 5.7 sq ft of opening, 20" wide, 24" high, and a sill no more than 44" above the floor. See Twin Cities egress windows.²
• Light and air: window glass equal to 8% of the floor area and openable area of 4%, or mechanical ventilation and artificial light as alternatives.²
• Heat: able to hold 68°F in every habitable room.²
• No fuel-fired appliances in, or drawing combustion air from, bedrooms, bathrooms or closets.²

Smoke and CO alarms

When permitted work removes wall or ceiling finishes, or a bedroom is added, the home needs smoke alarms placed as for new construction, interconnected and hardwired. Carbon monoxide alarms go outside and within 10 feet of each sleeping area, on every level with bedrooms, under Minnesota Statutes 299F.50.²

Old basement stairs

Existing stairs serving a finished habitable basement must meet minimums including 30" width, 6'4" headroom, an 8" maximum rise, a 9" minimum run, and a handrail 30" to 38" high.² Steep original stairs are common in older Twin Cities homes, so have a contractor measure them before you price the project.

St. Paul and the suburbs

The rules above come from the City of Minneapolis guide, which is based on the 2020 Minnesota Residential Code.² Because that code is statewide, St. Paul and suburban building departments enforce the same core rules, but each city runs its own permits and fees; check with the city where the house is.

Choosing a basement contractor in the Twin Cities

Ask the contractor to confirm ceiling heights under the ducts and beams before promising a bedroom, and to show how they'll handle egress, stairs and alarms. Then compare bids using the Twin Cities cost guide.

General information summarized from the public sources listed below. It isn't professional, engineering or legal advice. Codes and programs change; confirm current requirements with your local building department or utility before you start.