It's the Law - Egress Window Requirements
The IRC 2009 or International Residential Code pertains to all single and two family homes.
The intent of the code is to keep you and your loved one safe by requiring a means of egress in basement level living spaces. The reason for needing a means of egress are twofold; to allow for an exit in case of an emergency, and to provide access for a firefighter to gain entrance. You will find that each product on this site clearly states whether it complies with the egress window requirements.
The code gets updated every three years. Therefore there should be an updated version of it coming some time in 2012. Check with your local building department to determine what version of this code is being enforced in your area at this time.
Here is an overview of section R310 of the code that are applicable to Egress Windows:
Egress windows (or doors) are required in every habitable space. Especially in any room used for sleeping purposes, it will require its own egress window. Remodeler: if you have an existing home and you add a sleeping room, or finish a separate living space in the basement, the code requires that you install an egress window to serve these spaces. Without a means of egress, these rooms can represent a dangerous fire trap if you do not have a quick and easy to operate emergency egress escape window. If you have a basement that has a bedroom, recreation room, den, family room, media room, office, or home gym. All of these rooms are required to have a means of egress.
The bottom of the egress window opening can’t exceed 44” from the finished floor.
The minimum opening area of the egress window is 5.7 square feet.
The minimum egress window opening height is 24” high.
The minimum egress window opening is 20” wide.
The egress window must have a glass area of not less than 8% of the total floor area of room(s) for which it is servicing, to allow the minimum amount of sufficient natural light. *
The egress window must have a opening area of not less than 4% of the total floor area of room(s) for which it is servicing, to allow the minimum amount of natural ventilation. *
* Multiple windows can be used to service a single area where one window does not meet these percentages of total floor area. As long as the totaled amounts from this combination of windows meet or exceed the 8% for natural light and 4% for natural ventilation.
Egress window wells are required where the bottom of the egress window is below ground level.
The egress well must not interfere with the egress window fully opening.
The distance from the egress window to the back of the Egress well must be at least 36”
The minimum area of the egress well must be 9 square feet. (width x projection)
Egress ladders and or steps are required on window wells deeper than 44” and must be permanently attached.
An egress ladder or step may encroach into well up to 6”.
Steps and/or distance between rungs of the ladder can’t exceed 18”.
The rungs of an egress ladder must be 12” wide or greater and must project a minimum of 3” away from the back wall, but can’t exceed 6” from the back of the wall.
Shall be easily opened or removed from the inside of the egress well without special tools.
These requirements are intended to make sure an average, able bodied person, would be able to both fit through and lift themselves up, and out the window. Please keep in mind whom may be using the living space in your basement and adjust these requirements as you feel necessary. The law only dictates the minimum required by law and may not be what best suits your needs. Use your common sense when picking the egress window size and egress window well size that you feel is right for you and your family. Keep safety in mind.
See your local building inspector with questions regarding code requirements in your area. You are responsible for abiding by all applicable building codes in your area.