​Risk Category I

Buildings and other structures that represent a low hazard to human life in the event of failure, including but not limited to:

  • Agricultural facilities
  • Minor storage facilities
  • Certain temporary facilities
  • Screen enclosures

Risk Category II

 Buildings and other structures except those listed in Occupancy Categories I, III and IV.

Risk Category III

Buildings and other structures that represent a substantial hazard to human life in the event of failure, including but not limited to:

  • Buildings and other structures whose primary occupancy is public assembly with an occupant load greater than 300.
  • Buildings and other structures containing elementary school, secondary school or day care facilities with an occupant load greater than 250.
  • Buildings and other structures containing adult education facilities, such as colleges and universities with an occupant load greater than 500.
  • Group I-2 occupancies with an occupant load of 50 or more resident patients, but not having surgery or emergency treatment facilities.
  • Group I-3 occupancies.
  • Any other occupancy with an occupant load greater than 5,000a.
  • Power-generating stations, water treatment facilities for potable water, waste water treatment facilities, and other public utility facilities not included in Risk Category IV.
  • Buildings and other structures not included in Risk Category IV containing sufficient quantities of toxic or explosive substances to be dangerous to the public if released.

Risk Category IV

Buildings and other structures designated as essential facilities, including but not limited to:
 
  • Group I-2 occupancies having surgery or emergency treatment facilities. 
  • Fire, rescue, ambulance and police stations and emergency vehicle garages. 
  • Designated earthquake, hurricane or other emergency shelters. 
  • Designated emergency preparedness, communication, and operation centers and other facilities required for emergency response. 
  • Power-generating stations and other public utility facilities required as emergency backup facilities for Risk Category IV structures.
  • Structures containing highly toxic materials as defined by Section 307 where the quantity of the material exceeds the maximum allowable quantities of Table 307.1(2).
  • Aviation control towers, air traffic control centers and emergency aircraft hangars.
  • Buildings and other structures having critical national defense functions.
  • Water storage facilities and pump structures required to maintain water pressure for fire suppression.

 

​a For purposes of occupant load calculations, occupancies required by Table 1004.1.1 to use gross floor area calculations shall be permitted to use net floor areas to determine the total occupant load.