NFPA Journal®, January/February 2010

More than two decades have passed since the first edition of NFPA 13R, Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height, was published in 1989. One might think that all questions have been settled as to its intended scope of application, but the issue is still being debated.

From the start, the technical committee that wrote NFPA 13R stated that the definition of a "story" is left up to applicable building code. Under some codes, a habitable basement might be considered one of the maximum four stories, while under others, it would not, effectively allowing another story. By referencing the Life Safety Code® definition of "residential," the committee also made it clear that, while NFPA 13R considers board-and-care homes residential properties, nursing homes are not.

Annex material has long clarified that, where applicable, NFPA 13R can be used throughout a building, even in areas that might normally be classified as other occupancy types but which are incidental to the operations of the residential occupancy. In the 2010 edition, examples of such incidental uses, including parking garages or areas, community laundry rooms, clubhouses, exercise facilities, and tenant storage, have been added to the annex language.

At one point during the development of the 2010 edition, the committee considered allowing NFPA 13R to be used for the residential portion of a multiple occupancy, provided it was separated from other occupancies by a fire-rated assembly as required by the applicable building code to qualify as a separated occupancy. Other parts of the building could be protected in accordance with NFPA 13, Installation of Sprinkler Systems. Following public review, however, the committee decided not to make the change.

One argument made against such an allowance was that the use of NFPA 13 and 13R systems in the same building would confuse responding fire departments, add unnecessary complications for system designers and installers, and confuse building occupants about the level of sprinkler protection provided. It could also lead to the use of NFPA 13R systems at heights considerably above the intended four-story limit. Instead, the 2010 edition retains the annex advice that, where buildings are more than four stories high or are of mixed use where residential is not the predominant occupancy, NFPA 13 should be applied throughout, with residential portions of such buildings protected using residential or quick response sprinklers.

The experience with NFPA 13R systems over the past 20 years has been excellent. Although performance statistics are not maintained separately for NFPA 13R systems, the January 2009 NFPA report on sprinkler performance for 2003–2006 showed that the combined performance for the occupancy in which NFPA 13R systems are used most, apartments, was 98 percent, higher than that for the average of all types of structures, including those protected with NFPA 13 systems. Although the allowed omission of sprinklers from certain building areas for purposes of economical system installation has occasionally led to extensive property damage, reports from the field indicate this is a rare event.

The value of NFPA 13R has been demonstrated since its first publication by virtue of its widespread acceptance. The NFPA sprinkler performance report stated that, in 2006, 16 percent of reported apartment fires occurred in apartments with automatic extinguishing equipment. This compares to about 6 percent for apartments in the years leading up to the development of NFPA 13R. The significant growth can be credited to the publication of NFPA 13R in 1989, and its subsequent acceptance by building codes and multi-family housing builders.

NFPA 13R opened the door to a new level of acceptance of fire sprinkler protection in residential occupancies.

Russ Fleming, P.E., is the executive vice-president of the National Fire Sprinkler Assocaition and a member of the NFPA Technical Correlating Committee on Automatic Sprinklers.