Building Importance factor is selected on analysis settings by the user according to Codes.
International Design Codes
Notation in ASCE
Ie = Building Importance Factor
Buildings and other structures is classified according to the risk to human life associated with their damage or failure by nature of their occupancy according to Codes. According to seismic design codes, each structure should be assigned to the highest applicable Risk Category. Importance Factors by Risk Category of Buildings are specified in seismic design codes. Importance Factors are used to increase seismic effects.