According to the ADA, an egress window is defined as an "emergency escape and rescue opening." Egress windows can actually be a life-saving feature in your home, should you need to escape your home in a fire. The are, in fact, required by law in any room where someone sleeps, including a basement. An egress window can also be used by a fireman entering your house as they try to put the fire out. In order to make sure these windows are truly functional, certain egress windows requirements must be met.
The egress window needs to be a specific size. Because the purpose of an egress window is to not only allow you to climb out, but a fireman in full gear to climb in, the window must have a net opening consisting of 5.7 feet or more. The height of the window must be 24 inches high and at least 20 inches wide.
Location of Egress Window
The window cannot to be too high from the ground so that a person can either climb out it or in it without too much effort. To ensure this, make sure the egress window is 44 inches from the ground.
Operation of Window
Since the egress window can be used by someone trying to break into your house, you will probably want to have the ability to lock the window. This is perfectly acceptable. However, you need to be able to easily operate this window lock in the case of a fire. You do not want to find yourself in a situation where the house is on fire and you must search for a key to open the egress window. As the Virginia building code states, each lock or clasp "shall be releasable or removable from the inside without the use of a key, tool or force greater than that which is required for normal operation of the escape and rescue opening."
Access to Egress Window
If your egress window is located more than 44 inches from the floor, you need to provide a permanently affixed means to access the window. This can be in the form of a built-in ladder or even steps that are 12 inches wide and located not more than 3 inches from the wall.