Window well cost

A window well costs $300 to $1,500 installed, typically around $700. Adding drainage takes it to $600 to $2,700. A terraced or stepped well for an egress window is $800 to $3,000.

It is a small item that causes a disproportionate number of wet basements, because a well without a drain is a bucket held against a basement window.

What it costs

The drain is the whole point

A window well collects the water that runs down the wall and the surface water that reaches it. If there is nowhere for that water to go, it fills, and once it is above the window sill it comes in.

A correct well has:

• A drain in the base, either connected to the footing drain or run to daylight
• A gravel base, six to twelve inches deep, not soil
• The top edge above the surrounding grade by a couple of inches, so surface water does not run in over the lip
• The grade around it sloping away
• A cover

The most common defect is a well with a soil base and no drain. It works until a storm saturates the ground, and then it does not.

The second most common is a drain that exists and is blocked with leaves and silt, because there was no cover. Clearing it is a bucket and an hour; not clearing it is a flooded basement.

Covers, and why they matter more than they look

Water. A cover keeps rain and snowmelt out, which is most of what a drain has to handle.

Debris. Leaves and grit silt up the drain. A cover is what keeps it working.

Safety. An uncovered well is a three to six foot drop, and children and pets fall in. So do animals, which then have to be got out or removed dead.

Egress rules. If the window is an egress window, the cover must be openable from inside the well without tools, keys or special knowledge. A screwed-down grate on an egress window fails inspection and defeats the point.

Clear polycarbonate covers let light in, which matters if the window is the basement's main daylight. Steel grates are stronger and let more debris through.

For an egress window

Egress wells have their own requirements:

A standard well is typically too small and too shallow in projection for egress. If the window is being upgraded to egress, the well usually has to be replaced too, and that is part of why an egress window costs $3,000 to $8,000.

Frequently asked questions

My window well fills with water. What do I do?

Check whether there is a drain at all: dig down through the gravel in one corner. If there is one, it is probably blocked and can often be cleared or jetted. If there is none, adding one is $300 to $1,200 and it is the fix.

Can I just fill the well with gravel?

Gravel improves drainage within the well and it does not create an outlet. Water still has to go somewhere. Gravel plus a drain works; gravel alone delays the problem.

Are the decorative stone wells worth it?

They look considerably better than corrugated steel and they are structurally the same job. On a visible elevation the difference is worth the $300 to $1,000.

How deep should the gravel be?

Six to twelve inches below the window sill level, over the drain, so water reaching the base has somewhere to sit while it drains.

Do I need a permit?

For replacing a well, usually not. For a new egress window and well, yes, because the opening in the foundation is structural and the well dimensions are inspected.