Egress Window
A window large enough to serve as an emergency exit, required by code in every sleeping room including basements.
An egress window is a window that meets minimum size requirements set by the International Residential Code (IRC) to serve as an emergency escape route. The IRC requires a minimum net clear opening of 5.7 square feet (5.0 sq ft for ground-floor windows), a minimum clear opening height of 24 inches, a minimum clear opening width of 20 inches, and a maximum sill height of 44 inches above the floor.
Every bedroom—including basement bedrooms—must have at least one egress window. This requirement is why you cannot legally convert a basement space with small hopper windows into a bedroom without cutting in a proper egress window. Installing an egress window in a basement typically requires excavating a window well, cutting the foundation wall, and installing a liner.
Egress window installation in a basement costs $2,500–$5,500 depending on foundation type (poured concrete vs. block), window well size, and drainage. The work requires a permit and inspection. Converting a basement room to a legal bedroom bedroom with this upgrade can significantly increase appraised home value.
Real-World Example
The homeowner spent $3,800 cutting in an egress window and installing a window well so the basement room could legally be listed as a fourth bedroom.