In this case, the entire building would have to be sprinklered, or fire barriers would have to be constructed to limit each Group S-1 fire area to 12,000 square feet or less.
For example, Section 903.2.9, states that one threshold of sprinklering the entire building is when such a building contains a Group S-1 fire area of greater than 12,000 square feet.
WHEN IS FIRE SPRINKLER SYSTEM DESIGN NOT REQUIRED CODE
The figures below, excerpted from Figures 202.6(1) and 202.8(3) of the 2012 IBC Commentary (The International Code Council, 2011), show fire areas bounded by walls and ones bounded and unbounded by horizontal assemblies (rated and non rated).įire area appears in the building code mostly in Chapter 9 where it is used as a threshold for requiring either fire separation or fire sprinkler systems. Also note that fire partitions do not count in bounding fire areas. Note that, in this definition, multiple stories can be included in the calculation for fire area if each floor/ceiling assemblies separating each story are not rated horizontal assemblies (fire barriers). The fire area is the combined area of the floor in between fire walls, fire barriers, exterior walls or horizontal (fire barrier) assemblies within a building. Equipment platforms, per Section B505.3 are not used in determining the building area or the fire area. Per Section B505.2, the area of mezzanines are not included in determination of building area, but are included in the determination of fire area. When building area is mentioned in the IBC, it normally refers to the area of the largest story, which is typically the first floor. The building area is the area between exterior walls, excluding courts and vent shafts. This article uses the 2015 IBC as its basis, as that is the most common model code year for which commercial buildings are currently being built.įour concepts must be introduced in order to understand fire separations. See my earlier article “ WHEN ARE FIRE SPRINKLERS REQUIRED FOR NEW CONSTRUCTION?” for when sprinklers are required in buildings. One of the more confusing aspects of the IBC (The International Code Council, 2014) and one of the most common questions poised to a building engineer or architect is “When are fire separations required?” There is no simple answer to this question, because sometimes fire separation is a design alternative to sprinklering the entire building or portions thereof.