The word egress is defined as an EXIT. Since the main or first floors of homes/buildings provide doors as exits and windows that can be easily climbed through, exits need to be accessible on levels or rooms where an easy exit to the outside is not available.
An egress window meets specific size and code requirements intended to provide a safe emergency exit from a basement or lower level in a home. The benefits of installing an egress window are numerous, including increased natural light, improved ventilation, and, most importantly, increased safety and peace of mind in the event of an emergency.
Code requirements for egress windows vary depending on location, but generally, they require that the window be large enough for a person to fit through unimpeded. The International Residential Code (IRC) requires an egress window opening be no less than 5.7 square feet, with a minimum height and width of 24 inches. In addition to size requirements, code may also dictate the height of the window opening from the floor and the inclusion of a ladder or steps for easy escape.