As advocates work to achieve broader embrace of residential fire sprinklers, it is worthwhile to share the origins of NFPA 13D, the Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes. As more local and regional decisionmakers become familiar with NFPA13D’s purpose and goals, sprinkler installation will become an increasingly acceptable option to address both public safety and current housing issues.
Life Safety Standard Origin
NFPA 13D was first published in 1975 following the release of the landmark report America Burning: The Report of the Commission on Fire Prevention and Control. America Burning documented that an estimated 12,000 fire-related deaths were occurring annually in the US — the majority within the home. Following that report’s publication, NFPA established a committee charged with developing a standard for an installed fire protection system that would provide cost-effective life safety in homes.
Note that NFPA 13D only applies to one- and two-family dwellings and manufactured homes, while NFPA 13R encourages sprinkler installation in multi-family buildings. NFPA 13 addresses both life safety and property protection in buildings.
Since its adoption in 1975, NFPA 13D remains unique in its focus on cost-effective life safety and has continually evolved through our lived experience with these systems and the changing nature of fires in our homes. The standard’s requirements provide a high level of fire protection by delaying flashover, thereby giving occupants time to safely evacuate.
The standard judges where to install sprinklers within homes based on the highest-risk rooms from US fire statistics. NFPA states:
“The main goal of an NFPA 13D system is to provide life safety by preventing flashover for the first 10 minutes of the fire, which allows occupants time to escape while also allowing the system to be installed at a substantially lower cost than an NFPA 13 system. The cost of a system is reduced through materials, design, and the omission of sprinklers from spaces where fire loss statistics indicate that few deadly fires start.”
The NFPA 13D standard has other significant considerations not found in NFPA 13. This helps to encourage their broader adoption in one- and two-family dwellings. These include:
• Maximum 2 sprinklers activated when calculating sprinkler flows
• Only 10-minute water supply (7 mins if a single story under 2000 sq ft)
• Reduced discharge density at 0.05 gpm/sq ft or the sprinklers’ listing when calculating sprinkler flows
• Components (except sprinkler heads) are not required to be listed
• Special consideration for well systems and their recharge rates
• No maintenance or inspection requirements
Overcoming Local Challenges
In some Canadian jurisdictions we have seen issues arise around backflow prevention devices and their obligatory inspection. Due to concern for municipal water potability, some jurisdictions have sought to require backflow prevention devices on residential sprinkler systems. If required locally, these necessitate periodic inspection by the municipality, which often serves as a disincentive. To address this issue, some Canadian jurisdictions have approved flow-through systems – a toilet or other plumbing fixture is installed towards the end of the sprinkler system. The regular use of this fixture ensures that the water does not stagnate in the system and eliminates the need for a backflow preventer.
Another disincentive is water metering of sprinkler systems, often imposed by communities out of misguided concern for water usage. To recover perceived treatment costs, water purveyors may seek to install a water meter on the sprinklered system or impose standby charges on the water line for the sprinkler. These result in higher costs to a homeowner because a larger water line implies higher usage and higher wastewater. This is contrary to documented water-saving facts: Fire sprinklers benefit municipal water demand by reducing the size of water lines to the development. The sprinklers only flow when there is a fire and the water used by the sprinkler system is considerably less than that used by fire hoses (Research Technical Report: Environmental Impact of Automatic Fire Sprinklers Report). In contrast to installed sprinklers, firefighting flows are not treated and as such pose an environmental risk. Successful workarounds for these unnecessary cost burdens have included using a small installed tank to meet the water supply requirements (thus obviating the need for an increased service line and meter) or only metering the domestic water usage.
As these examples make clear, it is essential that the approval authorities understand the principles behind these simple and cost-effective systems in new homes. Home fire sprinkler advocates should include education about the standard in their outreach as well as the solutions to address local challenges to installation acceptance.
In Canada, we are seeing an increasing number of annual home starts with sprinklers; in fact, they are advancing at a rapid rate. By understanding how these systems work and how the requirements are focused on cost-effective life safety, developers and planners are opening up development areas and making sprinklers an important part of the solution in Canada’s housing affordability problem. Check out our other blog posts on incentives and affordability.