The International Building Code, issued triennially by the International Code Council, requires that basement sleeping and habitable spaces have emergency egress or exit openings, according to Bob Vila. Local authorities might develop their own municipal building codes, but the majority of localities follow the International Code Council's guidelines.
Any basement egress window must open to the outside and must easily open without using either keys or tools, explains Bob Vila. As of 2015, the window must be at least 20 inches wide and 24 inches high. The opening must have at least 5.7 square feet through which a person can crawl.
The egress window's sill height must not be higher than 44 inches above the floor, specifies the International Code Council. If the window well depth exceeds 44 inches, then the International Building Code requires a permanent ladder or steps leading to the window. The required rungs must have an inner width of at least 12 inches and must project at least 3 inches from the wall. Steps of the ladder or rungs must be less than 18 inches apart vertically.
Basements that have a floor area that is 200 square feet or less and do not have any habitable spaces do no need to have emergency escape windows, notes the International Code Council.