For a class of high-rise public buildings and a class of high-rise public buildings with a building height greater than 32m, smoke-proof stairwells should be adopted for the evacuation stairs.

The evacuation stairs of podium and second-class high-rise public buildings with a building height of no more than 32m should be closed stairwells.

Note: When a firewall is installed between the podium and the main body of a high-rise building, the evacuation stairs of the podium can be determined according to the requirements of this code for single-storey and multi-storey buildings.

The evacuation stairs of the following multi-storey public buildings, except those directly connected with the open verandah, should adopt closed stairs:

1, medical buildings, hotels, old buildings and buildings with similar functions;

2, set up the building of song and dance entertainment places;

3 shops, libraries, exhibition buildings, conference centers and similar buildings with functions;

Other buildings with 4 or 6 floors or above.

The evacuation stairs of residential buildings shall meet the following requirements:

1, the building height is not more than 2 1m, and the open staircase can be used for residential buildings; The evacuation stairs set near the elevator shaft should adopt closed stairwells. When the door adopts Class B fire door, the open stairwell can still be used.

2. Residential buildings with a building height greater than 2 1m and not greater than 33m should adopt closed stairwells; When the door adopts Class B fire door, the open stairwell can be used.

3. Smoke-proof stairwells should be adopted for residential buildings with a building height greater than 33m. The door should not lead directly to the front room. When there are difficulties, the doors leading to the same front room on each floor should not be more than 3 inches, and class B fire doors should be adopted.