Are you installing your own window well?
To maximize gravel and drainage at the base of the well we recommend the following:
– For small window wells (less than 50″ width), put 4″ of drainage stone in the bottom of the well.
– Once you get beyond 56″ width we recommend 8″-10″ of drainage below so the window well is sitting on the drainage as well as fastened to the wall. We also recommend putting 12″ of drainage behind the window well so the backfill material isn’t settling against it.