International Residential Code (IRC) 2000
Egress code for one and two families:

Definition of egress as described in IRC 2000 (Section R310) as it pertains to windows below ground level:

Window Wells/Area Wells:
Required where window opening sill height is below ground elevation.
Horizontal dimensions: = 9 sq.ft. (width x projection)
Horizontal projection: = 36 "

Windows:
Sill height of window above floor: Not to exceed 44"
Minimum opening area: = 5.7 sq. ft.
Minimum opening height = 24"
Minimum opening width: = 20"

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

Grates:
Shall be removable without special tools.

Code sponsored by: The International Code Council (ICC), the Building Officials Code Administration (BOCA), the Uniform Building Codes (UBC), and the Southern Building Code Congress International (SBCCI).