Egress refers to the ability to emergency exit from any building. For residential dwellings the size of the egress opening is a matter of law. The International Residential Code states that all bedrooms must have either a door opening to the outside, or a window that has a 5.7 square foot opening minimum. Windows on the ground floor may have a minimum opening size of 5.0 square feet.
The second requirement of the egress code is that the bottom of the opening may not be higher than 44 inches off the floor. Return from Egress to Home Building Mentor