What Size Egress Window Do I Need in Ohio?

Ohio follows the International Residential Code (IRC R310): an egress window needs a minimum 5.7 square feet of clear opening area, at least 20 inches wide, at least 24 inches tall, with the sill no more than 44 inches above the floor. The window must open fully without tools, keys, or special knowledge.

Those are minimums — a window that's exactly 20 inches wide has to be unusually tall to hit 5.7 sq ft, so in practice we size windows a little larger for easier escape and more natural light. Summit County inspectors measure the clear opening with the sash fully open, not the rough opening, so the glass size and the way the window operates both matter.