1, the stairwell in the basement of a general residence is not limited in form, and does not need to be separated from the ground or directly outward. ? Residential basement and public underground garage should be separated by fire partition. ? 2. For underground and semi-underground buildings (rooms) with the height difference between indoor floors and outdoor entrance floors greater than 10m or three or more floors, smoke-proof stairwells should be adopted for evacuation stairs; For other underground or semi-underground buildings (rooms), the evacuation stairs should be closed stairwells. If natural ventilation cannot meet the requirements, a mechanical pressurized air supply system or a smoke-proof stairwell should be set up. (The stairwell form has nothing to do with the stairwell form of the above-ground building. )? 3. The first floor should be separated from other parts by a fireproof partition wall with a fire resistance limit of not less than 2.00h, and should be directly connected to the outside. When it is really necessary to open the door on the partition wall, Class B fire doors should be adopted. 4,? Stairwells should not be used in underground or semi-underground parts and above-ground parts of buildings. If it is really necessary to use stairwells, the first floor should adopt fire partition walls and Class B fire doors with a fire resistance limit of not less than 2.00h to completely separate the underground or semi-underground part from the above-ground part, and set up obvious signs. 5,? When the local stairwell is really difficult to directly lead to the outside due to conditions, it can directly lead to the outside of the first floor through the lobby on the ground for evacuation of stairs.