How is Hazard Occupancy Defined in the Uniform Building Code?

According to the Uniform Building Code, a hazard occupancy is a measure of the risk and consequences expected in the event of a fire. They are classified as a light hazard, ordinary hazard, or extra hazard. There may be structures with mixed classifications, and other factors such as the items stored can affect the level that is assigned.

Light Hazard

These occupancies are where the amount and combustibility of the contents are low and fires with low rates of heat are expected. Here are some examples of this type of occupancy:

  • Child care centers
  • Churches
  • Gymnasiums
  • Hospitals and clinics
  • Offices

Ordinary Hazard Group 1

Group 1 are occupancies are where quantities of combustibles are moderate and stockpiles do not exceed 8 feet and fires with moderate rates of heat release are expected. Some of these occupancies include the following:

  • Bowling alleys
  • Kitchens and bakeries
  • Laundries
  • Parking garages
  • Theaters and auditoriums
  • Welding and forge shops

Ordinary Hazard Group 2

In a Group 2 occupancy, the quantity and combustibility of contents are moderate. Stockpiles do not exceed 12 feet, and fires with a moderate rate of heat release are expected. Small amounts of flammable liquids may be exposed as required by normal operations. This classification includes, but is not limited to:

  • Engine and generator rooms
  • Laboratories
  • Printing shops
  • Libraries
  • Vehicle repair garages
  • Woodworking shops

Special Occupancies

Special occupancies are areas that can not be assigned to another classification because of special protection requirements. Some examples of this occupancy are:

  • Aircraft hangars
  • Flammable and combustible liquids
  • Missile assembly
  • Rubber tire storage
  • Warehouses