Seven types of buildings must be strengthening and repair immediately:

1. The original building alreadly reached the useful life, but don't remove the reconstruction of the building

2. Remove the original components, the original structure of the transmission path changed

3. Increases the load on the basis of equipment,the addition of electromechanical equipment, elevators, escalators and so on 

4. The original building uses the function to change

5. The original building in the roof or indoor layer, due to increased load

6. Elevator, staircase plane position changes, the original staircase removed, sealed floor openings, new openings are required reinforcement

7. Due to design changes or construction errors, the local location of the demolition