Window wells are constructed to provide light to basements, and also serve the purpose of an underground safety exit. Due to these safety concerns, window wells must be constructed according to International Building Codes (IBC) standards. These standards include window well dimensions, and the use of safety ladders and well covers.
Horizontal areas of a window well must be 9 square feet and have a minimum horizontal projection and width of 36 inches. This design standard is intended for the safe escape of an individual from below-ground living quarters in the event of an emergency.
Safety ladders or steps are required for window wells with a vertical depth of more than 44 inches, and they must be permanently fixed. Ladders or rungs are also required to have a width of at least 12 inches, and the ladder must protrude at least 3 inches from the wall. Additionally, these ladders must be centered within 18 inches of the full height of the window well.
Window well covers must fully open in order to allow an individual to exit the well area unrestricted. Additionally, they must be able to open with 30 lbs. of force or less, and capable of supporting a load of 40 lbs. per square foot.