Based on the level of necessity of remaining safe and functional during any post disaster period e.g. after a cyclone, or an earthquake, buildings, structures and related equipments are classified into five structure importance categories such as
Each building or structure shall be placed in one of the structure importance categories and provided with a structure importance coefficient for design against wind earthquake induced forces.
Essential Facilities :
1. Hospital and other medical facilities having surgery and emergency treatment area.
2. Fire and police stations.
3. Tanks or other structures containing, housing or supporting water or other fire-suppression materials or equipment required for the protection of essential or hazardous facilities, or special occupancy structures.
4. Emergency vehicle shelters and garages.
5. Structures and equipment in emergency-preparedness centres, including cyclone and flood
6. Standby power-generating equipment for essential facilities.
7. Structures and equipment in government communication centers and other facilities required for emergency response.
П) Hazardous facilities
Structures supporting or containing sufficient quantities of toxic or explosive substances to be dangerous to the safety of the general public if released.
Ш) Special occupancy structures
1) Covered structures whose primary occupancy is public assembly with capacity >300 persons.
2) Buildings for schools through secondary or day-care centers with capacity >250 students.
3) Buildings for colleges or adult education schools with capacity >500 students.
4) Medical facilities with 50 or more resident incapacitated patients, not included above.
5) Jails and detention facilities.
6) All structures with occupancy > 5,000 persons.
7) Structures and equipment in power-generating stations and other public utility facilities not included above, and required for continued operation.
ІV) Standard occupancy structures
All structures having occupancies or functions not listed above.
V) Low risk structures
Buildings and structures that exhibit a low risk to human life and property in the event of failure, such as agricultural buildings, minor storage facilities, temporary facilities, construction facilities, and boundary walls.