Egress window wells: size, ladders, drainage and covers

1. Foundation wall
2. Egress window
3. Clean gravel
4. Drain connected to the foundation drain
5. Cover that opens from inside

SoilConcrete / masonryWoodInsulationWater

What a basement window well does

A window well holds the soil back from a window set below the ground outside, so the window can get light and air. For an egress window, it also has to leave enough room to open the window all the way and climb out. See egress windows.

Egress window well requirements

Fairfax County’s guide to finished basements adds two practical points: measure the area with the window open, which matters with crank-out casements, and if the ladder sticks out more than 6 inches into the required area, the well has to be bigger. In Fairfax, a new window well also needs a plan submission (Fairfax County, Typical Finished Basement Details). These are Virginia’s figures; other states and localities can differ.

Window well ladders and steps

In deep wells, ladders and steps make sense, and I see them often. What matters to me is that they can really be used, not a small rusty ladder behind a window that barely opens. I also see wells where steps were added and then a cover or landscaping was put on top that makes them almost impossible to use. For the exact dimensions, I go by the Virginia Residential Code.

Why window wells fill with water

In my experience, roughly from most to least common:

1. The grade sends surface water into the well.
2. A gutter or downspout empties nearby.
3. The well’s drain is blocked, or there isn’t one.
4. The top of the well sits too low compared with the ground around it.
5. The gravel is full of soil and debris.
6. A high water table, or a footing drain that isn’t working.
7. The well has pulled away from the foundation wall, and soil and water get in behind it.

I’ve also seen basement windows sitting under a roof valley that sends a huge amount of water their way. More in yard grading and downspout drainage.

Window well drainage

I don’t want a window well to work like a bucket. Usually I want clean stone at the bottom, a real drain if the amount of water calls for it, and that drain connected to a system with an outlet: the footing drainage, another approved drainage system or, depending on the design, a sump system.

The Northern Virginia Soil and Water Conservation District describes the same idea: a central drain in the well, connected to an interior or exterior drain tile system or to a pipe that drains outside the house. Installing one means digging and reinstalling or replacing the well liner, it may need permits, and you have to call 811 before you dig (NVSWCD, Flood Proofing Practices).

What I see done wrong:

• six inches of gravel on top of clay, with nothing underneath;
• a pipe that just ends somewhere underground;
• a drain full of mulch;
• crushed corrugated pipe;
• a well tied into a footing drain that’s already failing, on the assumption that this fixes it.

Basement window leaking? Check the well first

Before you seal the window:

1. Clean out the well.
2. Look for standing water.
3. Check the grade around it.
4. Check the gutters and downspouts.
5. Find out whether there’s a drain.
6. Watch where the water actually starts.

If the well fills halfway up the window during a storm, caulking around the frame isn’t the main fix. The window should never be working as a small dam. For other ways water gets in, see water in the basement.

Window well covers

A grate is useful to keep people from falling in and to keep large objects out, but it doesn’t stop rain. A clear polycarbonate cover helps a lot with rain, leaves and snow while still letting light in. I prefer a custom-fitted cover when the well has an odd shape or when I need much better control of surface water. On an egress well there’s one basic condition: the person inside has to be able to get out. I wouldn’t use a cover that’s heavy, locked, screwed down or that needs a tool, and I don’t want it to take away the room needed to open the window or climb out of the well.

Liners, gravel and replacement

If a steel well has surface rust but is still solid and firmly attached, I don’t always replace it. I do replace it if it:

• is pulling away from the wall;
• is bent out of shape;
• has serious corrosion;
• lets soil in;
• sits too low;
• isn’t big enough for what it has to do.

Clean gravel is worth it because it keeps mud down and helps water reach the drain. But more gravel doesn’t fix a drain that isn’t there, and a nice plastic liner inside a well that fills with water doesn’t change much either.