Quick answer
To count as a legal bedroom in Minnesota, a basement sleeping room must have its own emergency escape and rescue opening — almost always an egress window. Under the Minnesota Residential Code, that window needs a net clear opening of at least 5.7 square feet, a minimum opening height of 24 inches, a minimum opening width of 20 inches, and a sill no more than 44 inches above the floor. If the window sits below grade, it also needs a window well with at least 9 square feet of horizontal area.
For Twin Cities homeowners, a professionally installed egress window — including concrete cutting, the window well, and drainage — typically runs in the range of $2,700 to $5,900, with national averages around $3,850 to $4,200. It is one of the highest-leverage line items in a basement remodel, because it is what legally transforms storage space into a bedroom.
Why egress windows matter in a basement remodel
An egress window is a code-required escape route. If a fire blocks the stairway, anyone sleeping in the basement needs a second way out that is large enough to climb through — and large enough for a firefighter in full gear to climb in. That is why the code regulates not just the size of the window, but how high it sits, how it opens, and the well outside it.
Egress also has a practical payoff beyond safety. A conforming bedroom can be counted in your home's bedroom total, which matters for appraisals and resale. And a properly sized egress window brings meaningful natural light into a space that would otherwise feel like, well, a basement. If you are weighing the bigger picture, our guide to basement remodel costs in Minneapolis breaks down where egress fits in a full project budget.
Minnesota egress window code requirements
Minnesota's rules for emergency escape and rescue openings follow Section R310 of the residential code, adopted statewide through the Minnesota Residential Code. The essentials:
Where egress is required
- Basements with habitable space need at least one emergency escape and rescue opening.
- Every basement sleeping room needs its own egress opening — one shared window down the hall does not cover multiple bedrooms.
- The window must open from the inside without keys, tools, or special knowledge.
Minimum window dimensions
- Net clear opening: at least 5.7 square feet (820 square inches). Note this is the actual open, climbable area — not the glass size or the rough opening.
- Minimum opening height: 24 inches.
- Minimum opening width: 20 inches.
- Maximum sill height: 44 inches above the finished floor.
A window that is exactly 24 inches tall and 20 inches wide does not meet code — that combination only yields about 3.3 square feet. In practice, at least one dimension has to be considerably larger to reach 5.7 square feet, which is why purpose-built egress windows are common.
Window well requirements
- Wells serving egress windows must provide at least 9 square feet of horizontal area, with a minimum projection and width of 36 inches.
- Wells deeper than 44 inches need a permanently attached ladder or steps that remain usable with the window fully open.
- Well covers or grates must open easily from inside without tools or keys.
Twin Cities specifics: permits, inspections, and our frost line
Cutting a new opening into a foundation wall is structural work, and cities across the metro — including Edina, Minneapolis, Minnetonka, and St. Paul — require a building permit and inspections for egress window installation. Several metro cities publish their own egress information sheets, and inspectors here look closely at the header or lintel over the new opening, waterproofing at the cut, and window well drainage.
Drainage deserves special attention in Minnesota. Our freeze-thaw cycles and clay-heavy soils mean a poorly drained window well can collect water, heave, or leak into the newly finished space. A quality installation connects the well to the foundation drain tile or a gravel drainage bed — a step that budget installers sometimes skip and homeowners rarely see until the first wet spring.
One more planning note: Minnesota updates its state building code on a six-year cycle, and the state has been working through its next residential code update. Requirements can shift at adoption, so before finalizing plans it is worth confirming current requirements with your city's building department — or working with a design-build firm that handles permitting for you.
What does an egress window cost in 2026?
Recent national cost guides put a professionally installed basement egress window at roughly $3,850 to $4,200 on average, with most projects falling between $2,700 and $5,900. Complex installations can exceed that. Typical components:
- Window unit and frame: $800–$2,000
- Window well: $400–$1,200 (decorative composite or stone wells run higher)
- Excavation and drainage: $800–$2,000
- Concrete cutting and lintel installation: $600–$1,500
- Waterproofing and flashing: $300–$600
- Permits and inspections: $150–$600
Enlarging an existing window opening costs less than cutting a brand-new one, and block foundations are generally easier to cut than poured concrete. If your basement plans include income potential, an egress window is also the non-negotiable first step — see our tips on converting a basement into a rentable side hustle.
Common egress mistakes we see
- Measuring glass size instead of net clear opening. Casement windows usually achieve the required opening in a smaller frame than sliders or single-hungs.
- Skipping the permit. Unpermitted bedrooms can stall a home sale, void insurance claims, and force costly rework.
- Ignoring well drainage. The window is only as good as the drainage around it.
- Forgetting the ladder. Deep wells need permanently affixed steps or a ladder — a frequent inspection failure.
Frequently asked questions
Does every basement bedroom in Minnesota need its own egress window?
Yes. Each basement sleeping room must have its own emergency escape and rescue opening. A single egress window elsewhere in the basement does not satisfy the requirement for individual bedrooms.
Can I use a door instead of an egress window?
Yes — a code-compliant door that opens directly to the exterior, such as a walkout basement door, satisfies the emergency escape requirement for that room.
Do I need a permit to install an egress window in the Twin Cities?
Yes. Edina, Minneapolis, Minnetonka, St. Paul, and surrounding cities require a building permit because the work modifies the foundation. Expect at least a footing/structural check and a final inspection.
Will an egress window add value to my home?
Generally, yes. It allows a basement room to be legally counted as a bedroom, which increases appraised value and marketability — a three-bedroom home listed as a four-bedroom is a meaningful difference in the Twin Cities market.
Planning a basement bedroom? Let's talk
Executive Remodeling designs and builds basement remodels across the Twin Cities metro, including Edina, Minneapolis, Minnetonka, and St. Paul — and we handle egress design, structural work, and permitting as part of every project. If you are thinking about adding a legal bedroom or finishing your lower level, contact us for a consultation and we will walk you through exactly what your basement needs to meet code and feel like home.
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