StairsRunsMinimum widthRequirements: 075m
Residential Design Code (GB50096-2011) No. 57.3: When one side of the staircase in the set is empty, the net width of the staircase should not be less than 075m；When there are walls on both sides, the net width between the walls should not be less than 090m, and a handrail should be provided on one side of the wall;
Code for Residential Design (GB50096-2011) No. 63.1: The net width of the stair run should not be less than 1For dwellings of 10m and no more than six floors, the net width of the staircase with a railing on one side should not be less than 100m；
Code for Fire Protection Design of Buildings (GB50016-2018) No. 64.5.Article 1: The height of the handrail of the outdoor evacuation staircase should not be less than 110m, the net width of the staircase should not be less than 090m。
The staircase in the suite is generally used for vertical transportation in two-storey dwellings and duplexes. When one side is in the air, its clear width should not be less than 075m；When there are walls on both sides, the net width between the walls should not be less than 090m, which is the minimum width for moving furniture and daily hand-held things up and down the stairs.
In addition, when there are walls on both sides, in order to ensure the safety of residents, especially the elderly and children, to go up and down the stairs, handrails should be installed on one side of the wall.
The clear width of a stair run is the horizontal distance between the wall cladding and the center of the handrail. The minimum clear width of the staircase is determined according to the comprehensive factors such as the use requirements, modulus standards, and fire protection regulations.
Outdoor stairs can be used as smoke-proof stairwells or closed stairwells, but they are mainly used as auxiliary for emergency escape of personnel and firefighters directly entering the building from the outside to reach the fire floor for fire extinguishing and rescue. For some buildings, outdoor evacuation stairs can also be used for evacuation due to the tight floor area.