What does "horizontal exit" refer to in building design?

A horizontal exit refers specifically to an exit that allows occupants to move to an adjacent building or area at the same level. This design is important in fire safety and building egress because it provides a means of escape without requiring individuals to ascend or descend stairs, which can be critical during an emergency when stairs may be unsafe or congested.

Horizontal exits are typically used in large buildings to offer an alternative route during evacuations. They enhance the overall safety strategy by allowing occupants to move laterally away from danger, often leading to a safer, unaffected zone. This type of exit can significantly improve evacuation efficiency, especially in multi-story buildings where vertical movement can be particularly hazardous during a fire or other emergencies.

In contrast, exits leading to the roof could potentially place occupants in a location where they are still at risk. Exits solely for service personnel might not be available or accessible to all occupants during an emergency. An exit located underground would not fit the definition of a horizontal exit as it implies a downward movement rather than lateral displacement within the building’s layout.