An egress window code is a legal requirement intended to ensure a person can escape a building through a window in an emergency. Most codes also require the windows to be large enough for a fully outfitted firefighter to enter through them. The term "egress" simply means a direct method of leaving a building, and an egress window code requires each bedroom in a home to have a direct exit available in the event of a fire or other emergency.
Building codes often are regulated locally, so there may be differences in the specific requirements for escape routes. In general, though, an egress window code requires a window for each bedroom in a home, as well as one in the basement, if it contains livable space. If there are individual bedrooms in the basement, a separate egress window is required for each.
Most local communities in the United States and Canada have based their building codes on the International Residential Codes (IRC) created by the International Code Council, a membership organization that promotes building safety and fire prevention. These codes were developed with input from both organization members and the construction industry. The IRC includes specifications for egress window sizes and locations, which vary slightly depending on which floor of the house the bedroom is on.
According to the IRC, egress windows should be a minimum of 20 inches (50.8 cm) wide, at least 24 inches (60.96 cm) high, and have a minimum net clearing opening of 5.7 square feet (0.529 square meters) for anything except a ground-level bedroom. The clearing opening is lowered to 5 square feet (0.464 square meters) for a ground-floor bedroom because a ladder isn't needed to escape. The sills on egress windows can be no higher than 44 inches (111.76 cm) from the floor.
For basement egress windows, there are also codes that regulate the sizes of the window wells, which is the area surrounding the window on the home's exterior. The wells must provide 9 square feet (0.83 square meters) of floor space and be a minimum of 36 inches (91.44 cm) in width and height. A well taller than 44 inches (111.76 cm) must include steps or a ladder that is permanently attached. The ladders are required to be at least 12 inches (30.48 cm) wide and not extend more than 3 inches (7.62 cm) above the window well.
Egress window codes were created to provide a safe means of escape from a building, so anything that could hamper that is prohibited. Bars, screens, and grates on an egress window must be easy to open and remove without the use of tools. Any type of window may be used as an egress, but it must provide an opening of at least 22.5 inches (57.15 cm) wide and 36.5 inches (92.71 cm) tall.
Most new homes are built to comply with the IRC recommendations, though homebuyers may want to perform a quick check with the local codes enforcement department for specific details about local regulations. Older homes that were built prior to the adoption of the IRC regulations may not meet the code requirements, although in those cases, an egress window code will typically not be enforced unless the home is renovated. A mortgage lender may require the home be updated to meet code if it is sold or refinanced, however. Even if there are no requirements to add an egress window, it remains a valuable safety feature that will often add value to a home.