Window wells at emergency escape and rescue openings should have a horizontal area of at least ___ square feet.

Window wells at emergency escape and rescue openings are designed to provide a safe exit route in emergencies, particularly from basements. The requirement for a minimum horizontal area ensures that individuals can easily escape without obstruction.

The correct answer specifies that a window well should have at least 9 square feet of horizontal area. This measurement is crucial because it allows enough space for occupants to maneuver through the window and provides adequate accessibility for rescue personnel if needed. The prescribed size is derived from safety codes developed to enhance egress in residential buildings.

Having a window well that meets this size may also contribute to the overall aesthetics and function of the space, ensuring that it is both practical for emergencies while serving as an effective part of the building's architecture. Adhering to these guidelines is essential for compliance with applicable building codes and for ensuring occupant safety.