Means of egress

Means of egress is the code's term for the path out of a building in an emergency. It is one of the oldest life safety requirements in the code and one of the least negotiable.

In houses

For one and two family dwellings, the requirements people meet most often are:

• Every sleeping room and basement needs an emergency escape and rescue opening, in practice a conforming window or an exterior door
• The opening has minimum dimensions for clear width, clear height, and total clear area
• The sill has a maximum height above the finished floor
• A window well serving a below-grade opening has its own minimum size, and needs a ladder above a certain depth

The specific numbers come from the adopted code edition, and they have changed between editions, so it is worth checking against the edition in force rather than from memory.

In commercial buildings

Egress becomes considerably more involved: number of exits based on occupant load, maximum travel distance, corridor widths, exit separation, door swing direction, panic hardware, illumination, and signage. Occupant load calculations drive most of it, which is why occupancy classification and egress are reviewed together.

Why it comes up in remodels

Egress is the requirement most often triggered by finishing a basement or converting a space into a bedroom. Adding a closet and calling a room a bedroom creates a sleeping room in code terms, and the escape opening requirement follows.