Building Classification - Fire Sprinkler Systems, Part 1
by Ronald L. Geren, RA, CSI, CCS, CCCA

This year marks the 200th anniversary of the automatic fire sprinkler system. In 1806, an Englishman by the name of John Carey developed the first automatic fire sprinkler system by connecting a series of perforated pipes to an elevated water tank. The water, under pressure due to the tank elevation, was held in place by closed valves. Combustible cords connected to weights held the valves closed. When a fire would burn through the cords, the weights would drop, opening the valves, thereby allowing water to enter the perforated pipes and extinguishing the fire. Crude, but it was only the beginning.

Although the first sprinkler head was invented in 1864 by Major Stewart Harrison of London, the first practical modern sprinkler head was developed ten years later by Henry Parmelee of New Haven, Connecticut. Upset with the extremely high insurance rates of the time, Henry Parmelee developed his sprinkler head to protect his piano factory rather than pay for insurance coverage. Later, he teamed up with Frederick Grinnell, who owned a steam and gas plumbing company at the time, to install the sprinkler systems in other factories at their request. Over 130 years later, the automatic fire sprinkler system remains the leader in fire protection systems.

The success of automatic fire sprinkler systems created another problem: consistency in installation. To resolve this problem, a group of men, the majority of which represented insurance companies, gathered in Boston in early 1895 to discuss this very issue. Later that year, they met again in New York, and the beginnings of a new sprinkler standard, and an association to maintain this standard, started to develop. By March of 1896, they developed a set of sprinkler installation rules and set in motion the development of an organization to adminis ter them.

In November 1896, the National Fire Protection Association (NFPA) was organ ized, and the sprinkler installation rules eventually became known as NFPA 13, Installation of Sprinkler Systems. Although NFPA 13 has become THE standard for sprinkler systems, many people don’t really understand when fire sprinkler systems must be installed.

NFPA 13, or amended versions of it, has been referenced in the building codes for many years, as well as its sister document, NFPA 13R Installation of Sprinkler Systems in Residential Occupancies Up to and Including Four Stories in Height. It wasn’t until the publication of the 2000 International Building Code (IBC) that the third fire sprinkler standard, NFPA 13D Installation of Sprinkler Systems in One- and Two-family Dwellings and Manufactured Homes, was referenced in a building code. Although the standards establish how the sprinkler system is to be installed, it doesn’t dictate the conditions when a sprinkler system is required to be installed—that’s left to the building code, or, in some case, local ordinance, which will be discussed later.

In the IBC, there are two ways that fire sprinklers may be required in a building: through either a direct requirement and or an indirect requirement. A direct requirement is one that the designer has little to no control over such as one based on an occupancy group. On the other hand, an indirect requirement is one that the designer does have control over, such as allowable building area and occupancy separations.
In the IBC, sprinkl er system requirements are found in Chapter 9, and, it is in Section 903 that you’ll find most of the direct requirements for automatic sprinkler systems. For example, in Section 903.2.5, it states that fire sprinklers “shall be provided throughout buildings with a Group I fire area.” Another example of a direct requirement—and one commonly misunderstood—is the requirement for a sprinkler system in all buildings with a Group R fire area. Some have mistakenly applied this requirement to all residential buildings; even detached oneand two-family dwellings and multiple single-family dwellings not more than three stories in height. The IBC Commentary clearly states that the International Residential Code (IRC), which is applicable to those building types, is considered a separate code, and that the requirements of the IBC do not apply. Conversely, if a building of any of those types does not meet the requirements for application of the IRC, then the IBC will apply and a sprinkler system will be required.
Additionally, there are other areas in the IBC where direct requirements for sprinkler systems are set. In Chapter 4, covered mall buildings must have a sprinkler system installed throughout, as well as high-rise buildings and in atriums. In Chapter 26, freezers, coolers, and the parts of the building where they’re located, must also be protected wit h sprinkler systems.

As for indirect requirements, the most common is the installation of a fire sprinkler system to obtain an area increase, a height increase, or both. The reason this is considered an indirect requirement is that alternative design approaches, other than the installation of a fire sprinkler system, can be incorporated to achieve additional floor area or building height. For example, a higher construction type may be used, providing separated occupancies, incorporating fire walls to separate large buildings into two or more smaller buildings, or a combination of any of those methods.

Other indirect requirements can be found when incidental use areas are included in a building design. Incidental use areas are spaces that could be classified within a separate occupancy group from the main occupancy, but are incidental to the main occupancy and, therefore, can be classified under the main occupancy. These areas, which are listed in Table 302.1.1, have options that either requires a fire barrier separation, the installation of a sprinkler system in the incidental use area, or both.

There are numerous other instances in the IBC where the installation of a sprinkler system—considered an active fire protection system—is permitted to reduce passive fire protection such as fire-resistive construction and finish classification; or increase other aspects of the code such as maximum allowable hazardous material storage, unprotected opening area, and maximum travel distance for egress. These are what the building code community calls “sprinkler trade-offs” and have been included in building codes for 50 years.

To comment on this article, suggest other topics, or submit a question regarding codes, contact the author at ron@specsandcodes.com

About the Author: Ronald L. Geren, RA, CSI, CCS, CCCA, SCIP, is an ICC Certified Building Plans Examiner, and is the principal of RLGA Technical Services located in Scottsdale, Arizona, which provides specification and code consulting services to architects, engineers, owners, and product manufacturers. A 1984 graduate of the University of Arizona, Ron has over 22 years of experience with military, public, and private agencies.