Residential sprinkler systems in New York City must be built according to the NYC Building Code, the NYC Fire Code and any applicable standards from the National Fire Protection Association (NFPA). In general, the NFPA 13 standard covers requirements for the installation of sprinkler systems, but modified versions are available for residential buildings.

• NFPA 13D: Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes
• NFPA 13R: Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies

NFPA 13D and 13R were developed to address the unique needs of the residential sector. This article will provide a brief overview of both standards, including the requirements that must be met to use them instead of NFPA 13.

Why Residential Buildings Have Dedicated Sprinkler Standards

Occupants of commercial buildings are generally aware of their surroundings, allowing them to react fast if there is a fire. However, this does not apply to residential settings:

• Occupants who are asleep may be unable to react on time when there is a fire. By the time they are awakened by the heat or smoke, it may be too late.
• Some occupants may be unable to save themselves even if they are awake when the fire occurs. For example, this can affect children, seniors and individuals with special needs.

In 1973, the NFPA Committee on Automatic Sprinklers created a team to develop a standard addressing the needs of one- and two-family dwellings. The result was the first version of the NFPA 13D standard, published in 1975. The main design goal was to provide a system that gave occupants enough time to ensure their survival, while being inexpensive. When the concept was expanded to larger residential buildings, the result was NFPA 13R, first published in 1989.

NFPA 13D: Overview and Usage Requirements

The NFPA 13D standard can only be used in one- and two-family dwellings and manufactured homes. It cannot be used for residential spaces that are part of a larger building, even if they are have one or two dwellings; in these cases the sprinkler system must be designed according to NFPA 13 or 13R, whichever applies for the building in question.

Sprinkler systems built according to NFPA 13D are designed to prevent flashover in residential spaces, one of the key risks associated with fires. To validate the performance of sprinkler systems built according to standard 13D, NFPA carried out 60 tests in a two-story dwelling and 16 tests in a mobile home. It is important to note, however, that residential sprinkler systems built according to NFPA 13D may not be able to control a fire if the fuel load is above-average for a residential dwelling, or if flammable interior finishes are used. NFPA 13D provides the following recommendations to maximize sprinkler systems effectiveness.

• Keeping the fuel load below 10 pounds per square foot.
• Using interior finishes with a flame spread index below 225 according to ASTM E 84.

NFPA 13R: Overview and Usage Requirements

The NFPA 13R standard was developed after the lessons learned from NFPA 13D were applied to larger residential buildings. It is important to note that the official publication is for low-rise buildings up to four stories high, but the NYC Department of Buildings has amended the standard to allow its use in buildings up to six stories high. In addition, residential buildings must not exceed 60 feet in height, or otherwise the sprinkler system must be designed according to the normal NFPA 13 standard.

A sprinkler system built according to NFPA 13R is also capable of preventing flashover, while controlling fire in residential spaces below a specified fuel load and flame spread index. It is important to note that NFPA 13R applies not only for residential dwellings themselves, but also for common areas of low-rise constructions. The following are some examples of these accessory areas:

• Garages and parking areas.
• Laundries
• Clubhouses
• Gyms and other exercise facilities
• Storage areas used by tenants outside of individual dwellings

It is important to note that the normal NFPA 13 standard has also been amended after NFPA 13D and 13R were published. Residential spaces in buildings covered by NFPA 13 must use sprinklers rated for residential use, just like those specified in NFPA 13D and 13R.

New York City Amendments to NFPA Sprinkler System Standards

NFPA 13, 13D and 13R do not apply directly for NYC residential buildings. As previously mentioned, the NYC Dept. of Buildings has introduced amendments that are covered in Appendix Q of the Building Code. These amendments also cover other fire protection systems such as standpipes, fire pumps and fire alarms.

One of the main modifications introduced deals with NYC Fire Department connections. The code does not require them in buildings covered by NFPA 13D, but they can be added at the owner’s discretion. However, if the decision to add them is made, they must meet all the requirements of a mandatory Fire Department connection. On the other hand, at least one connection is mandatory in buildings covered by NFPA 13R.

In buildings covered by either NFPA 13D or 13R, the sprinkler system is allowed to share a water supply with normal plumbing fixtures, as long as two requirements are met:

• The water supply must be equipped with a device to prevent flow for domestic plumbing fixtures when the sprinkler system is operational.
• Closing the main sprinkler control valve must also shut off the domestic water supply.

The code also points out that any sectional control valves located in piping that supplies water to the sprinkler system must be locked in the open position, and equipped with signaling device that indicates they are open.

Conclusion

Fire protection requirements in New York City are among the most demanding in the world, which should come as no surprise given the high concentration of buildings and population. With professional guidance and installation services, property owners can ensure their sprinkler systems meet any applicable requirements. A residential sprinkler system below standards is not only illegal; it also represents a risk for building occupants.