When finishing a basement with windows, creating and maintaining window wells is a necessary step. Like taking steps to prevent water infiltration, installing a subfloor, and insulating walls, creating a window well and installing a cover is one of those necessary first step sub-projects that let you get to the fun things later on, like building a home bar or installing a home theater.
Window Well Basics
Traditionally, basements were not meant to have windows. The low light and controlled temperatures were necessary for long-term food storage. But modern homeowners usually demand fenestration in their basements. Without windows, basements have far less utility as living spaces.
On one end of the spectrum are day-light basements, which have one or more sides at grade level. This means that you can walk straight out and be on the ground, no steps up necessary. The other sides of the basement will be banked up against earth. On the daylight side, wells are not needed. You can conventionally install windows.
At the other end of the spectrum are basements that, except for the upper foot or so, are fully underground. When you install a window in such a basement, you need to create a type of dug-out on the exterior. This dug-out is the window well.
The window well is your opening to the outside world, bringing some measure of air and light to the basement. In some cases, window wells must be of specific dimensions to allow for egress in case of emergency.
Why Uncovered Window Wells Are a Problem
Window wells often start in a good manner, with sturdy and solid dirt sides, but begin to deteriorate with the elements. Rain, snow, drainage, window, and human contact all contribute to the collapse of the window well sides. These sides eventually collapse onto your window.
Dirt banked up onto your window eventually spells disaster. Dirt is a vehicle for termites and carpenter ants, both of which can burrow into your home's structure and destroy it. Dirt, too, acts as a conduit to invite tree roots and water into your house.
Keeping these basement windows exposed means that anything that is outside at-grade (water, snow, leaves, dust, etc.) can reach your window. Basement windows tend to get a real beating from water dripping off of roofs and from ground-flow rain, so they deteriorate quickly. Windows are weather-resistant, but only to a point.
What Are Window Well Covers?
Window well covers are the solution to a window well collapse. Well covers act like a storm door for your basement window, providing extra protection for this heavily battered area.
Window well covers are half-circular, bubble-shaped, or rectangular galvanized steel or polyethylene shields that attach to the side of the house, supporting the earth and blocking debris, leaves, and moisture from reaching the basement window. They fit into an existing well and attach to the house. Some window well covers are transparent plastic (polycarbonate) to allow as much light as possible to reach the basement.
Efficiency experts have discovered that window well covers can save you energy and money because they help prevent heat from escaping.
Egress Window Wells Required by Building Code
If your local building code requires that your basement window provide egress (access to the outside in case of emergency), then window well dimensions will be large. Not only that, egress window wells may need to have some kind of steps or ladder system for occupants to use for escape.
Horizontal dimensions should be large enough to allow the window or door to be fully opened. The total area of the well should be at least 9 square feet. Outward from the house, the window well should project at least 36 inches. The height of the well should be no more than 44 inches, as higher well walls are considered to be hindrances to escape in the event of an emergency.
As always, check with your local permitting office to verify building codes in your area about basement egress, window wells, and window well covers.