Public circulation and evacuation circulation are two very different kinds of movement in a building. The first is the route people use in everyday life and for leisure, much like the sightseeing paths in a classical garden, where the building is experienced from the viewer’s point of view. The second is closer to the service routes used by attendants in traditional gardens: the shortest possible path, designed to meet evacuation needs as quickly as possible in an emergency.

The difference in stairs

Sightseeing stairs are meant to attract and guide people, strengthening spatial orientation.

Evacuation stairs are different. Under normal use, they do not need to follow functional zoning, and during evacuation they can cross functional zones. They may also be placed in less visible locations.

In major design exams, what is usually tested is the evacuation stair. If a project includes a special stair, such as a sightseeing stair, the drawings will generally note it clearly.

Fire safety and evacuation design

Fire safety design starts from the overall layout and technical strategy, moving from the site plan to the scheme drawings.

The boundary of each fire compartment must be complete. Fire compartments are separated by fire walls, while fire partition walls are only used to divide areas, zones, or rooms within a compartment.

Different functional zones need partition doors. If they belong to different fire compartments, fire doors or fire shutters are required instead.

Safety exits are set for fire compartments, while evacuation doors are used for ordinary rooms.

Except for Class A and Class B rooms, evacuation doors are not restricted in opening direction if the room occupancy does not exceed 60 people and the number of people served by each door does not exceed 30.

Evacuation distance

First stage

This is the distance from the farthest point inside a room to the evacuation door. For a large open space, the limit is 37.5 m inside the room + 12.5 m from the evacuation door to the stairwell. For a parent-child room arrangement, the distance from the farthest point in the inner room to the evacuation door in the outer room must be less than 45 m.

Second stage

This is the distance from the evacuation door to the safety exit, usually the stairwell. The required limit changes according to different conditions.

Third stage

If the stairwell leads directly outdoors, and the building has no more than four floors, then when an enlarged enclosed stairwell or a smoke-proof stairwell is used, the distance from the stairwell door to the door leading directly outdoors must not exceed 15 m.