Although fewer than two percent of all new homes have them, single-family residential fire sprinkler systems may soon follow the same path smoke detectors did during the 1980s. In other words, within the next 10 to 15 years they may well become mandatory in all new single-family construction. As it is, an estimated 600 to 700 cities throughout the country already have adopted ordinances pertaining to fire sprinkler systems in single- and multi-family homes. The trend seems to be gaining momentum.

"My case load jumped significantly this year," says Patrick Coughlin, Director of Operation Life Safety, "telling me that interest in residential fire sprinkler ordinances is increasing." Operation Life Safety is a public/private partnership whose goal is to reduce residential fire deaths and injuries through the use of fire sprinklers and smoke alarms.

"The demand for residential sprinklers up to now has been driven primarily by ordinances," Coughlin says. "I see some changes, though. I have received inquires from builders who are offering sprinklers as an option, and I have not received inquires like that before."

Why the growing interest? A look at the advantages residential fire sprinkler systems offer and how they have benefited two communities, in particular, provide some answers.

Preventing Flashover

According to Coughlin, "Residential fire sprinklers operate quickly enough to stop a fire before flashover occurs. In fact, they operate quickly enough to keep the room of origin tenable to life. Without them, the room becomes untenable to life about halfway to flashover." Flashover is the sudden spread of fire over an area when the combustibles in that area reach a temperature sufficiently high enough for them to burst into flame.

"The high load of synthetics in our homes creates fires that burn twice as hot and grow twice as fast as they did in the past," Coughlin notes. "As a result, smoke production is a magnitude higher. We now see time to flashover dropping to five minutes, which means that fire departments often cannot get enough personnel there in time to stop flashover."

For many fire protection districts, fire sprinkler systems allow them to work more efficiently with less personnel and infrastructure. Because they prevent fires from reaching flashover, there are fewer multiple-alarm fires.

Saving Tax Dollars

Scottsdale, a fast-growing suburb of Phoenix, Arizona, encompasses 182 square miles and has a population of 175,000. On January 1, 1986, the Scottsdale City Council implemented Ordinance #1709 mandating the use of fire sprinklers in all new single-family residences. Based on the Scottsdale Fire Department's belief that equipping new homes with fire sprinklers would greatly reduce the severity and duration of fires originating in those homes, the ordinance included the following changes:
  • Housing density was allowed to increase by 4 percent.

  • Minimum street widths were reduced to 28 from 32 feet.

  • Maximum cul-de-sac lengths were increased from 600 to 2,000 feet.

  • Hydrant spacing was increased from 600 feet to 1,200 feet, resulting in immediate savings of $2,000 per hydrant as well as ongoing future maintenance costs.

  • Required fire flow demand was reduced by 50 percent, which resulted in a typical one-step reduction in water main size and allowed for smaller water storage tanks.

  • One-hour construction standards were eliminated. Actual live testing indicated that when non-rated materials were used in conjunction with the proactive protection of fast-response sprinklers, the structure had a better chance of being less impacted by the growth and destruction associated with a typical residential fire. "In real life experience," a 1997 report on the Scottsdale ordinance notes, "the theory of one hour compartmentalization is an optimistic assumption that might be effective if people did not move into the structure."
At the time the ordinance was proposed, the major impact was a projected infrastructure saving of $7.5 million for the water distribution system. In addition, it was anticipated that the sprinkler ordinance would result in reducing the size or eliminating entirely at least three fire stations at savings of $6 million in capital costs and $1 million in annual expenses.

"Sprinklers cut the demand for fire department services by one-half," Coughlin says. "For example, the recommended response for a pre-flashover fire in a single-family detached home averages 12 firefighters, plus two pumpers, one ladder truck and a fire chief. To be effective, the first apparatus is expected to arrive within four minutes travel time and the remaining units within six minutes travel time. This requires stations to be closer together, so any reduction in demand can allow fewer stations per square mile."

Even with the alternatives offered, the National Association of Homebuilders continued its long-standing opposition to residential fire sprinklers. According to the report, "The (NAHB's) members take extraordinary steps to see (that) this type of concept does not gain support or become widely practiced." Despite NAHB's efforts, the ordinance passed by a 6-1 vote.

How well has the Scottsdale ordinance worked? A study examined the effects of the ordinance over its first 10 years and, based on 18 single-family fire sprinkler incidents during that time, presented the following results:

  • The average fire loss per sprinklered incident was $1,689, compared to non-sprinklered costs of $9,571.

  • Total sprinklered loss was $30,402, while the total potential loss was estimated at $5.4 million.

  • Installation costs dropped over the period of the study, from $1.14 per square foot to $.59 per square foot. This was due, in part, to increased efficiency and competition, as well as better availability of quality materials.

  • Homeowners' insurance rates were an average 10 percent less compared to similar non-sprinklered homes.

Building In Fire Protection

Barrington, an upscale suburb of Chicago, was the first Illinois city to enact a residential fire sprinkler ordinance. It did so on August 1, 1997, by mandating fire sprinklers in single-family homes within unincorporated areas of the 58-square-mile Barrington Fire Protection District. The ordinance was extended last year to include the city of Barrington itself. The total population served by the fire district is 30,000 people. The city currently has 56 new homes under construction, with an additional 60 approved for construction this year, all of which will have built-in fire sprinkler systems.

Barrington Fire Chief Dave Danley was the moving force behind the ordinance's adoption. "The public has a misconception about what a fire department can do," Danley says. "Although people like to think that we're infallible, we're not always going to be able to save the children in a burning home. The best job we can do as a fire department is to build in fire protection. Eighty-two percent of fire deaths occur in homes. People are dying in unsprinklered single-family homes, not in grocery stores and movie theaters, which, ironically, have sprinkler systems."

Due primarily to Danley's efforts, the ordinances were unanimously approved by Barrington's city council. Once again, however, opposition came from the NAHB, which flew several staff members from Washington, D.C., to Illinois specifically to address the council. According to Danley, the NAHB's reasons are based on their claim that "modern day" residential construction methods do not warrant the need for fire sprinkler systems.

"What people don't realize," Danley says, "is that it's not the house that causes the fire; it's the people in the home."

A substantial part of NAHB's claim is based on a study by the California Building Industry Association (CBIA). The study, which reviewed residential fire deaths in California during the period 1986-1991, concluded, "The overwhelming majority (90.6 percent) of California's residential fire fatalities are occurring in the older housing stock (pre-1972). Mandating sprinklers in new residential construction is clearly an ineffective (not to mention costly) response to the current fire fatality program." The report makes no mention of property loss due to fire.

An article in the January 1999 edition of the Operation Life Safety newsletter takes issue with the CBIA study: "Any simple correlation like this that does not account for the relative proportion of older vs. new housing stock will obviously find more fires (and thus more deaths) in older homes. Their findings are contradicted by analysis of national data by state over wider time frames, as the NFPA has done."

Most of the homes in Barrington's unincorporated areas have domestic water wells. Because water flows from the wells (36 gpm at 47 psi) were deemed sufficient, most of the homes do not have a separate fire pump and holding tank. Eliminating the fire pump and tank saves each homeowner about $2,000. Because 85 percent of residential fires are controlled by one or two sprinklers, it was felt that the flow from the wells would provide sufficient protection without mandating a fire pump.

A typical installation in a residence supplied by Barrington's municipal water system is shown in Figure 1. The main and domestic shut-off valves are ball valves, used because they are easier for inspectors to tag and lock out than gate valves. The fire sprinkler line is located between the service entrance and the water meter because the meter manufacturer was concerned about legal liability that might arise from diminished water flow resulting from the additional frictional loss incurred as the water passes through the meter. The sprinkler system water flow alarm is wired to an orange strobe light on the home's exterior, thus alerting neighbors that a sprinkler has activated and allowing them to notify the fire department. If desired, the water flow alarm can be connected to a remote monitoring service in the same way that home intrusion alarms are.

Standards and Designs

NFPA 13D covers single-family site-built and manufactured homes. Other associated standards are NFPA 13, which governs sprinklers in non-residential structures and residential buildings higher than four stories, and NFPA 13R, which applies to multi-family residences (e.g., apartments and condos) up to four stories.

A recently adopted change to NFPA 13D should help reduce installation costs of residential fire sprinkler systems. The change allows multi-purpose systems (those that serve both sprinklers and plumbing fixtures through common lines) to use 1/2-inch plumbing pipe. Prior to the change the pipe had to be 3/4-inch minimum and be listed for sprinkler systems.

In the past, residential fire sprinklers discharged up to 18 gallons of water per minute and required 16 psi. Some newer sprinklers discharge as little as 9 gpm and require a pressure of only 9 psi.

Sidewall sprinklers with a UL residential listing differ from other types of sprinklers in that they spray water in a uniform pattern high on the walls, instead of an umbrella spray pattern. This configuration directs most of the water along the walls, where the heat plume is usually located in residential fires. As a result, fire growth is stopped more quickly. In addition, residential sprinklers typically respond five times faster.

Multi-purpose Systems

A multi-purpose sprinkler system shares its piping with the plumbing system. One of the major cost savings of such a system is eliminating the need for backflow prevention devices, which typically add about $600 of the cost of a residential sprinkler system. According to Franz Haase, fire protection sales manager with Wirsbo Co., "a multi-purpose system eliminates concerns over stagnant water because system flow is maintained by the plumbing fixtures."

Wirsbo currently is developing a system that combines supply-side plumbing and the sprinkler system. The "grid" system uses a single manifold to distribute runs of 1/2-inch PEX tubing to four-port fittings which, in turn, feed the sprinklers and plumbing fixtures. Using two, 1/2-inch supply lines to each sprinkler allows the system to maintain the required flow to each sprinkler, eliminating the need for 3/4 inch supply lines. Hot water lines are piped in the traditional manner. According to Haase, 85 percent of the plumbing within the Wirsbo system is used for domestic purposes, while 15 percent is used for the fire sprinkler system. An additional advantage of the system is the need for fewer fittings because flexible pipe is used.

Although not enough installations have been completed to calculate actual savings, Haase estimates that multi-purpose systems, such as the one under development by Wirsbo, could save up to 50 percent over separate domestic and fire protection systems. Haase says he is hopeful that as their use increases, the installed cost for the sprinkler side of the systems will be around $.50 per square foot. Several systems are now being installed in Oregon, with a nationwide market introduction set for January 2000.

"Because the combined system is essentially a plumbing system with enhanced function, it can be installed by specially trained plumbers," Haase says. "However, because the system is a new concept, code treatment is expected to vary across different jurisdictions."

Educating Homeowners

One of the major obstacles to the increased use of residential fire sprinklers is homeowners who don't realize that such systems exist. "Many home buyers are not even aware that they can have a fire sprinkler system installed in their homes," Danley says.

Other obstacles to overcome include homeowners who mistakenly believe that when a fire sprinkler system activates all of the sprinklers go off. Once homeowners realize that each sprinkler acts individually and that typically no more than two sprinklers are activated, their concerns are lessened.

Another misconception is that extensive water damage will result when a sprinkler activates. Typically, however, a sprinkler operates less than 10 minutes before being shut off by fire department personnel. During that time, less than 200 gallons of water have been used. This compares to the 200 gpm rate or higher used by fire trucks responding to an unsprinklered incident.

"Because considerably less water is used and the fire is controlled much quicker," Danley says, "families are able to return to the home an average of one to two days after a sprinklered incident. In non-sprinklered incidents, homeowners are typically displaced from six to 12 months."

Installation Costs and Concerns

According to the American Fire Sprinkler Association (AFSA), fire sprinklers add about one percent to the cost of a new home. If a home has a complex floor plan or unique architectural features, costs may be higher due to the need for additional sprinklers and piping.

Another factor affecting cost is the availability of qualified installers. In areas where single-family sprinkler work is common, such as Scottsdale, costs can be up to half of what they are in areas where few new residences have sprinkler systems. Because home sprinkler systems are not used extensively in most communities, it is sometimes difficult to find a qualified residential fire sprinkler installer.

According to Pat Pritchard, vice president of Professional Plumbing Inc., a Barrington-based firm that installs plumbing systems in 3,000 homes a year, "There's a big difference between commercial and residential fire sprinkler work. As a result, many commercial installers treat residential work as a nuisance. In addition, most commercial installers aren't accustomed to working under the tight schedules that we encounter."

For those looking for contractors capable of installing residential fire sprinkler systems, one source is the AFSA, which maintains a list of about 200 contractors who bid and install fire sprinkler systems in single- and two-family residences. The list can be accessed through AFSA's website listed at the end of this article.

Looking into the Crystal Ball

Although demand for home sprinkler systems will continue to grow, it's difficult to gauge how rapid that growth will be. As Coughlin notes, "I think that sprinklers will eventually become a standard for new homes, just like smoke alarms. Their effectiveness at saving lives and preserving property is too great to go unnoticed. However, we haven't reached a 'tipping point' yet where enough consumers are aware of the product to create significant increase in demand."

Because of the increasing awareness and use of single-family fire sprinkler systems, Danley believes they will be addressed by the model codes within the next 10 to 15 years. He also points out that his department has answered hundreds of requests from cities and organizations around the country by sending out copies of the ordinances used in Barrington.

"But the key is to educate our children," Danley says. "That's where the real demand will come from, just like it did with smoke detectors. When our children are educated and they come home from school and ask their parents, 'Mom and Dad, how come we don't have a fire sprinkler system?' then eyes will be opened and demand will grow."