Building Code Basics

The International Residential Code 2000 stipulates the following for windows below ground level:

Window Wells/Area Wells:

  • Required where window opening sill height is below ground elevation.
  • Horizontal dimensions=9 square feet (width x projection). Horizontal projection=36 inches.

  • Sill height of window above floor: Not to exceed 44 inches.
  • Minimum opening area=5.7 square feet.
  • Minimum opening height=24 inches.
  • Minimum opening width=20 inches.

  • Required on window wells deeper than 44 inches and must be permanently attached.
  • Ladder may encroach into well up to 6 inches.
  • Step distance between rungs=18 inches.
  • Rungs: 12 inches wide or greater and must project a minimum of 3 inches away from wall but maximum of 6 inches.

  • Shall be removable without special tools.

Under Decks:
The International Residential Code 2006 stipulates the following for basement egress windows under decks:

Emergency escape windows are allowed to be installed under decks and porches provided the location of the deck allows the emergency escape window to be fully opened and provides a path not less than 36 inches (914 mm) in height to a yard or court.