In a Minnesota winter, an egress window well stays usable with three things: a cover that keeps snow out but opens from inside without keys, tools or special knowledge, a well floor that drains to the foundation drain tile as R310.2.3.2 requires, and a location away from roof runoff, drifts and the snowblower's throw.
Ask the manufacturer for the cover's load rating in writing, since the code does not set one, and never pile snow on it. I prefer composite wells with molded steps and a clear cover for bedrooms, because they will not rust and they bring in the most daylight.
On this page
- Why does a Minnesota winter change how you build an egress well?
- How do you keep snow and ice out of an egress window well?
- What are the rules for egress window well covers?
- How should the bottom of an egress window well drain?
- Steel or composite window wells: which is better for Minnesota?
- Should the well floor be rock or a liner?
- How do you keep the escape path clear all year?
- How does a window well affect the light in a basement room?
- How this plays out in the reference Twin Cities basement
- Questions people ask
Why does a Minnesota winter change how you build an egress well?
An egress window well is an escape route that sits in a hole in your yard. Every snowfall, every thaw and every refreeze lands in it. The code writes the well's size and ladder for a person climbing out, and it assumes the well is clear when that person needs it. In a Twin Cities winter, that assumption is something you have to build and maintain on purpose.
The base rules come from Section R310 of the Minnesota Residential Code, laid out in Saint Paul's handout: a well at least 9 sq ft in area with 36 in of projection and width, room for the window to open fully, a permanent ladder or steps when the well is deeper than 44 in, and a window that opens from inside without keys, tools or special knowledge. I cover sizing and the bedroom side in my post on a legal basement egress bedroom. This post is about keeping that path working from November to April.
| Winter problem | What goes wrong | What I design for |
|---|---|---|
| Drifted and plowed snow | Snow fills an open well, burying the window and the ladder | A cover that keeps snow out and still opens from inside |
| Thaw and refreeze | Meltwater pools at the well floor and freezes against the window and sill | A drained well floor tied to the foundation drain, plus grading away from the well |
| Ice on the cover or ladder | The cover freezes shut or the rungs ice over | Covers you can test in winter, kept off the roof drip line; a regular check after storms |
| Leaves and debris | The well floor clogs, so meltwater cannot drain | A cover, and a fall cleanout before snow |
| Water against the glass | Pooled water leaks around the window opening | Sealed window, sealed well, drained floor |
How do you keep snow and ice out of an egress window well?
Three things keep a well usable in winter: a cover, drainage, and placement. A cover keeps most snow out. Drainage gets rid of the water when that snow melts. Placement keeps the well out of the spots where snow piles up in the first place.
Place the well where snow does not pile
On a suburban lot the worst spots are under a roof valley or eave without gutters, beside the driveway where the snowblower throws, and on the side of the house where wind drifts. When I pick the bedroom wall, I check the roof above it and the path of the snowblower as carefully as the property-line setback. Prior Lake, for example, requires a 5 ft setback from the property line and keeps wells out of drainage and utility easements. If the only workable wall is under an eave, the gutter above it is part of the design.
Clear it after storms
A cover makes clearing easier, but it does not make it optional. After a heavy snow, clear the snow off and around the cover so it can still be pushed open from below, and look down the well for ice at the sill. If someone sleeps in that room, this belongs on the same list as shoveling the front steps.
Never pile shoveled or blown snow on top of a window well or its cover. The weight can exceed what the cover was built for, and a buried cover is a blocked exit.
What are the rules for egress window well covers?
Covers are allowed. The rule is that the cover cannot stop the window from working as an escape. The escape opening has to operate from the inside without keys, tools or special knowledge, and Prior Lake's handout says covers or screens are permitted if their net clear opening, when open, still meets the egress requirements. In practice that means:
- It opens from below by hand. No padlock, no screws, no latch that needs a key or a tool. A person standing in the well, including a child, has to be able to push it open or release it.
- It opens far enough. When the cover is open, the clear opening above the well cannot be smaller than what the code requires for the escape path.
- It does not trap the ladder. The ladder has to be usable with the window fully open and the cover open.
If you want a lock for security, choose a cover with a latch that releases from the inside only. Never put a keyed lock on an egress cover. Ask your city's inspector before you buy; they would rather answer a question than fail a final.
Load ratings
The code sections in the Twin Cities handouts I used do not set a snow-load or walk-on number for well covers. That number comes from the manufacturer. The Basement Systems product pages I checked describe clear covers that keep out pests, rain, snow and debris, but they do not publish a load rating. My rule: get the rating in writing for the exact cover, and know the difference between a cover rated to shed snow and one rated for a person to walk on. A well beside a walkway, or anywhere kids play, needs the walk-on kind or a guardrail. Saint Paul's diagram recommends a 36 in guardrail where a well sits next to a property line or sidewalk.
| Cover type | Strengths | Watch for |
|---|---|---|
| Clear dome or flat polycarbonate/acrylic | Lets light through; sheds rain and light snow | Ask for the load rating; confirm it lifts or hinges open from inside |
| Hinged egress cover with a release | Built to open from below; can carry a rated load | Hinge clearance with the ladder; the release must not need a key or tool |
| Steel grate | Strong against foot traffic | Lets snow and leaves straight in; must still lift from below |
| Plywood, tarp or a screwed-down panel | None for an egress well | Fails the escape rule as soon as it is fastened down; do not use |
How should the bottom of an egress window well drain?
Drainage is a code requirement, not an upgrade. Section R310.2.3.2 says window wells must be designed for proper drainage by connecting to the building's foundation drainage system required by R405.1, or by an approved alternative. The exception is a foundation on well-drained ground or sand-gravel soils (Group I soils in the IRC soil table). Unless your city accepts your lot's soil as Group I, plan on the connection, and ask your inspector early.
The foundation drain itself is defined in R405.1. InterNACHI's summary of that section gives the key dimensions: drain tile or perforated pipe rests on at least 2 in of washed gravel or crushed rock and is covered by at least 6 in of the same material, and a gravel drain extends at least 6 in above the top of the footing and at least 1 ft beyond the outside edge of the footing. Perforated pipe gets a filter membrane unless the manufacturer says otherwise. The well's job is to give water a path down to that system instead of letting it pond against the window.
What that looks like in the well
- A drain path at the bottom of the well, reaching the foundation drain tile, through washed rock, or a vertical drain pipe down to the tile.
- Washed rock in the well floor rather than soil, so meltwater soaks down instead of pooling.
- The well floor below the window sill, so standing water never reaches the glass.
- Grading that slopes away from the house around the well. InterNACHI notes the IRC's recommended fall of 6 in within the first 10 ft.
Interior drain tile works too. Basement Systems sells a low-profile channel that connects the base of a well to its interior perimeter drainage. In a house where the drain tile runs to a sump, that is the same water ending up in the same pit. Keep the sump healthy (my sump pump guide covers it), because a failed pump in a thaw backs water up everywhere at once.
Why it matters: Basement Systems points out that water weighs nearly 8.5 lb per gallon and that a well full of water can leak around the window opening and flood the basement.
Steel or composite window wells: which is better for Minnesota?
Both work if they meet the size and ladder rules. The differences are durability, appearance and light.
| Corrugated galvanized steel | Composite / reinforced plastic (molded) | |
|---|---|---|
| Durability | Can rust and corrode over time; Basement Systems notes rusted wells can let in rain and snow | Basement Systems says its reinforced plastic wells will not rust or corrode |
| Ladder | Usually a separate bolted-on ladder | Often has steps molded into the wall; confirm they meet the 12 in / 3 in / 18 in rules |
| Appearance from inside | Ribbed metal wall outside the bedroom window | Molded finishes, some textured like stone |
| Light | Gray metal reflects little | Light colors bounce more daylight into the room |
| Installation | Bolted to the foundation | Flanges sealed and fastened to the outside of the foundation |
For a finished bedroom, I specify a composite well with molded steps in almost every case. The view out a bedroom window is the inside of that well, so the composite well's light color and finished face matter more here than anywhere else in the house. Steel is fine for a shallow utility window that nobody looks at.
Should the well floor be rock or a liner?
The floor has two jobs: drain and stay clean. Washed rock drains; a solid floor stays clean. A solid vinyl floor, like the one Basement Systems describes in its SunHouse well, keeps out dirt and weeds, but water that lands on it still needs a path out. If the well serves an egress window, I want the well floor to drain to the foundation drain system. A liner or solid floor is only acceptable when it is part of a system with its own drain path. Ask what happens to meltwater before you buy one.
| Well floor | Pros | Cons |
|---|---|---|
| Washed rock over a drain path | Drains freely; what R310.2.3.2's drainage connection looks like in most installs | Leaves and soil fill the voids over time; needs a cover and a fall cleanout |
| Decorative liner or solid floor | Clean look, no weeds | Must have its own drain; a sealed floor with no drain is a bathtub against your window |
| Soil or sod | None | Holds water, grows weeds, freezes; I do not use it |
How do you keep the escape path clear all year?
The escape path runs from the bedroom floor, through the window, up the ladder and out to a yard. Everything along that line needs to stay usable:
- Inside the bedroom: do not block the window with a bed, a dresser or a built-in. The sill is 44 in or less from the floor so a person can reach it; furniture in front defeats that.
- The window: test that it opens fully each fall. If you add window opening control devices for kids, Saint Paul's handout says they must comply with ASTM F2090, so they still release for escape.
- The cover: open it from below once a season, and once after the first big snow.
- The ladder: knock off ice, and check that nothing is stored in the well.
- Outside: keep a path at least 36 in high under any deck or porch over the window, and do not plant shrubs or stack firewood over the well.
Teach whoever sleeps in that room how the window and cover open. The code requires an opening that needs no special knowledge; a practice run in daylight makes sure nobody needs it at night.
How does a window well affect the light in a basement room?
An egress well is also the biggest daylight source in most basements. Basement Systems notes that egress windows add light and that a light-colored well directs sunlight into the basement. Three choices shape how much light reaches the room:
- Well finish: a light-colored well wall bounces daylight down into the window; dull gray steel reflects less.
- Cover type: a clear cover keeps snow out and lets light in; a solid or grated cover cuts light. In winter, snow on a clear cover blocks light until you clear it.
- Well projection: a deeper projection opens more sky above the window. The 36 in minimum is about escape, not light.
Even with a good well, a basement bedroom gets less daylight than an upstairs room, so I light it as if the window were a bonus. My basement lighting guide has the layout.
How this plays out in the reference Twin Cities basement
In my reference house, a 2000s two-story in Lakeville or Maple Grove with a poured foundation, the new bedroom's egress window goes on the back wall, away from the deck and outside the snowblower's throw. It is a casement in a composite well with molded steps and a light finish. The well floor has washed rock over a drain path to the foundation drain tile, which runs to the sump. A clear cover that hinges open from below keeps snow and leaves out, with a written load rating from the manufacturer. Grading slopes away on all three sides of the well, and the downspout above discharges well past it.
Each fall the owner clears leaves out of the well, tests the window and the cover, and checks that the downspout extension is on. After each big snow they clear the cover. That is a short list, and it is the difference between a bedroom with a working exit in February and a window with a block of ice against it. The permit side of this work is in my guide to basement permits in Minnesota.
Check with your city: drainage details, guardrail needs, setbacks and whether a particular cover is acceptable vary by Twin Cities city. Bring the cover's spec sheet to plan review.
How BuildFlow does it
BuildFlow Basements designs and prices your finished basement, and licensed, insured local contractors build it — one fixed price, agreed before work starts.
It starts with me, Emma, BuildFlow’s free AI designer. In about five minutes I design your own basement: renderings of your space, real products you pick, and a real price range for your project. The design is yours to keep, even if you never hire BuildFlow.
Design my basement with EmmaQuestions people ask
Can I put a cover on an egress window well in Minnesota?
Yes. Covers are allowed as long as the escape still works: the cover must open from inside without keys, tools or special knowledge, and Prior Lake's handout says that when it is open, the clear opening must still meet egress requirements. Never fasten an egress cover down or put a keyed lock on it.
How much snow load can a window well cover hold?
That depends on the product. The code sections in Twin Cities city handouts do not set a load number for covers, so get the manufacturer's rating in writing for the exact cover. Never pile shoveled snow on a cover, and use a walk-on rated cover or a guardrail near walkways.
Does an egress window well need a drain?
Yes, in most cases. R310.2.3.2 requires window wells to drain by connecting to the foundation drainage system or an approved alternative. The exception is foundations on well-drained Group I soils. A well that cannot drain lets water pool and freeze against the window.
What should go in the bottom of a window well?
Washed rock over a drain path to the foundation drain tile, with the well floor below the window sill. Soil holds water and freezes. A solid liner floor only works if the system includes its own drain.
Are steel or plastic window wells better?
Both are allowed if they meet the 9 sq ft, 36 in and ladder rules. Galvanized steel can rust over time, while reinforced plastic or composite wells do not rust, often have molded steps and reflect more light. For a bedroom, I specify composite.
How do I keep ice out of my egress window well?
Put a cover on it, make sure the well floor drains to the drain tile, slope the grade away and keep roof runoff and snowblower throw off it. After big storms, clear snow off the cover and check the sill and ladder for ice.
Does a window well cover reduce light in the basement?
A clear cover lets most light through, and a solid or grated cover cuts it. Snow sitting on any cover blocks light until you clear it. A light-colored well wall and a well with more projection bring in the most daylight.
Sources (8)
- City of Saint Paul DSI: Emergency Escape and Rescue Openings handout (2020 Minnesota Residential Code, R310) — R310 well size 9 sq ft and 36 in, window must open fully, ladder over 44 in deep, ladder rung rules, R310.2.3.2 drainage to foundation drain or approved alternative with Group I soil exception, operation without keys or tools, ASTM F2090, deck 36 in path, guardrail recommendation
- City of Prior Lake: Egress windows handout — Covers or screens allowed if their clear opening when open meets egress requirements; 5 ft property-line setback and easements
- InterNACHI: Foundation drainage below grade (IRC R405.1) — IRC R405.1 foundation drain details: 2 in gravel under pipe, 6 in over, 6 in above footing, 1 ft beyond footing, filter membrane, Group I soil exception, 6 in fall in 10 ft
- Basement Systems: Window well drain (WellDuct) — Water nearly 8.5 lb per gallon; pooled water leaks around the window; channel connecting well base to interior drainage
- Basement Systems: Basement windows and window wells — Rusted, corroded wells can let in rain and snow; debris can clog a well and cause flooding; egress windows add light
- Basement Systems: SunHouse window well — Reinforced plastic well that will not rust; solid vinyl floor; clear cover keeps out pests, rain, snow and debris; light color directs sunlight; comparison with corrugated steel
- Basement Systems: Egress window well (RockWell) — Reinforced plastic egress well, built-in steps, flanges sealed and fastened to the foundation, clear cover, no published load rating
- Minn. R. 1309.0310, Section R310 Emergency Escape and Rescue Openings (Office of the Revisor of Statutes) — Minnesota amendments to R310 (basement sleeping rooms, new sleeping rooms in existing basements)
More in Minnesota
- How does Minnesota's climate affect a finished basement?
- Should I worry about radon before finishing my basement in Minnesota?
Keep reading
- What does a basement bedroom need to be legal in Minnesota?
- Do I need a permit to finish my basement in Minnesota?
- What should I check and upgrade on my sump pump before finishing my basement?
- How do you keep a finished basement from getting moldy?
- How do I light a basement with no windows so it doesn't feel dark?