Egress

Egress refers to the means of exiting a building safely — and in construction it specifically means the code-required paths and openings that let occupants escape in an emergency, especially a fire. The most common place homeowners encounter egress rules is the "emergency escape and rescue opening" required in sleeping rooms: a window or door large enough, and low enough, for a person to climb out and for a firefighter to climb in.

Egress is central to ADU projects and basement or garage conversions, because turning a non-bedroom space into legal sleeping or living space usually triggers egress requirements. A converted basement bedroom, for example, often needs an egress window well; a finished attic may need a conforming stair. These requirements are a frequent reason a conversion costs more than expected, and they are checked closely during plan review and again at inspection.

Building codes set minimum dimensions for egress openings — a minimum clear width, height, and net opening area, plus a maximum sill height above the floor — along with rules for the number and arrangement of exits in larger spaces. The exact figures come from the building-code edition a jurisdiction has adopted, and local amendments vary, so the specific numbers differ from place to place.

Because egress is a life-safety standard, it is rarely waived; a design that cannot meet it usually has to be reworked rather than approved through a variance. Satisfying egress is part of what a project must clear before it earns a certificate of occupancy. This is a general overview, not code advice — confirm the current egress requirements for your project with your local building department before you design or convert a space.