Egress
Also known as: Egress window · IRC R310
The code-required escape opening from every sleeping room — minimum 5.7 sq ft clear opening.
Egress refers to the code-mandated escape route from every sleeping room in a dwelling. Under IRC R310, every bedroom must have a window or door opening directly to the exterior with a minimum 5.7 sq ft clear opening, max sill height of 44 in, and a minimum 20 in width and 24 in height. Basement AADUs almost always need egress window wells excavated and waterproofed — a $4K–$9K line item that catches many homeowners off-guard.