How Far From the Ground Should an Egress Window Be?

Dimensions

• The IBC states that an egress window must be at least 20 inches wide and 24 inches high. The window must be close enough to the floor to reach, or a maximum of 44 inches from the floor to the sill. The net clear opening, or the total space available to crawl through, must be 5.8 square feet for secondary windows and 5 square feet for ground floor windows. Second floors require a larger net clear opening because they need to accommodate emergency ladders and fire fighters wearing full gear.

Safety Devices

• According to the IBC, egress windows may include safety devices, such as bars, grates or grills. However, the safety device may not be attached with parts that require tools or keys.

Basements

• If your egress window is in a basement, the IBC requires the same distance from the floor to the sill, or 44 inches. Basement egress windows must also open fully and provide a floor exit area of at least 9 square feet and 36 inches of height and depth. If there is a sunken well space outside the window, an escape ladder must also be available.

Considerations

• Not all windows that fill the IBC's 20-inch width requirement or 24-inch height requirement will satisfy the net clear opening. A 20-inch wide, 24-inch high window has a net clear opening of only 3.3 square feet. This means that either width or height must be increased to make up the difference. To calculate the square footage in inches, multiply the height and width, which should equal at least 5.8 square feet, or 821 square inches.