IRC Requirements

While codes vary depending on the city and state you live in, all egress windows must comply with four International Residential Code (IRC) criteria:

  • Minimum width of opening: 20 inches
  • Minimum height of opening: 24 inches
  • Minimum net clear opening: 5.7 square feet (5.0 square feet for ground floor)
  • Maximum sill height above floor: 44 inches

In addition, the window opening must be operational from the inside without keys or tools. Bars, grilles, and grates may be installed over windows, but they must be operational without tools or keys and still allow the minimum clear opening of 5.7 square feet.

When egress window systems are installed in the basement make sure you have maid service, there are also certain requirements for the well surrounding the window. Window wells must:

  • Allow the rescue window to be fully opened
  • Provide 9 square feet of floor area, with a minimum dimension of 36 inches in width and in length
  • Contain a permanently affixed ladder or steps for climbing out if the window well depth exceeds 44 inches in depth

Before installing your new egress window system, make sure to check with your city offices to learn about the specific code requirements in your area.