Recent technological advances and new cost savings are increasing the flow of sprinkler systems into residential construction, fire protection experts report.

The National Association of Home Builders estimates that 60 to 70 percent of its builder members offer sprinklers now, usually as options, compared with 20 to 30 percent a few years ago.

The impetus has come from the adoption in 1980 of the first house-sprinkler standard by the National Fire Protection Association. The code, inspired by the U.S. Fire Administration's 1973 commitment to reduce by half the annual loss of life in fires, was designed primarily to make home sprinklers more affordable.

The new code specifies what types of piping may be used, the number of sprinklers needed to cover a specific area and other installation guidelines for fire protection contractors.

Before, the association lumped residential, industrial and commercial sprinkler requirements together and, as a result, separate piping and larger water supplies were called for. The industrial-commercial standard is basically designed to protect property, while in the home-sprinkler standard, the focus is on saving life.

According to the association, 5,446 people died in home fires in the United States in 1980.

The immediate effect of the new code has been to halve the price of home sprinklers by permitting builders to tie the devices into normal domestic plumbing.

While some home sprinkler advocates contend that a new house can be fitted with the systems for as little as 1 percent of the cost of construction, fire protection consultants indicate that the cost ranges from $1,700 to $2,000 for a typical 2,000-square-foot dwelling.

Fire sprinklers are considered impractical and too costly for retrofitting into existing homes, but that situation might change if sidewall sprinklers under development receive approval by the fire association and Underwriters Laboratories, experts said.

Neither the U.S. Fire Administration nor the fire protection association could provide figures on the number of homes with sprinkler systems. Fire protection experts, however, believe the number of systems in use nationwide to be only about 2,000, with the bulk of those installed last year in San Clemente, Calif., after that city became the first municipality in the country to require sprinklers in new houses.

But the new technologies and lower costs, some fire protection officials even believe that, within three to five years, most new residences will have the systems.

In the long run, the cost of installation insurance breaks. The Insurance Service Office, an industry rating organization, recommends a 50 percent discount on a premium where a fire association-approved sprinkler system has been installed. Virginia and Maryland are among the states whose insurance regulators have allowed the savings. In both states, it is up to the individual insurance company to determine how much of a discount to offer.

But consultants say the best news in home sprinklers may be the introduction of a "quick-response" head.

The new outlet releases water five to 15 times faster after being activated than the old heads, which were designed primarily for industrial use, according to Harry Shaw, the recently retired assistant administrator for the U.S. Fire Administration.

Shaw said that the extra speed is important to keep the home temperature below that necessary to produce carbon monoxide, hydrogen chloride and other toxic gases from synthetic carpeting and upholstery. He noted the temperature of a room on fire can quickly rise from 80 degrees Fahrenheit to 600 degrees Fahrenheit.

Ron Coleman, director of fire protection for San Clemente, Calif., said he has received inquiries from 800 fire departments across the country since 1978, when his city became the first municipality in the United States to require sprinklers in new houses.

In Orange County, Calif., construction is not allowed in many areas far from fire stations unless sprinklers are installed in the buildings.

Public officials are also giving developers financial incentives, such as allowing more units of housing on less land and narrower streets if the fire protection systems are present. Virginia permits three-story, multi-family wood frame dwellings to be constructed without sprinklers. If the builder puts in a sprinkler system, he can add a fourth story to the building.

In the suburbs of Atlanta, the Cobb County Fire Department is going further than most with incentives. Fire Chief David Hilton is allowing builders to use less fire-resistant wallboard and doors and eliminate firewalls where sprinklers are installed in multi-family units.

The only sprinkler heads approved by Underwriters Laboratories, made by Grinnell Fire Protection Systems Co., Inc. of Providence, R.I., can sprinkle an area of six feet. But instead of four sprinkler heads required in a room larger than 12 x 12 feet square, as the fire protection association requires with these heads, Chief Hilton is allowing builders to get by with installing only two in the larger rooms.

Chester Schirmer, chairman of the fire protection association technical committee overseeing the sprinkler issue, thinks Cobb County may be sticking its neck out a bit:

"There is no such thing as a rule that measures differently because you don't like what it says."

Schirmer, however, calls the new home sprinklers the greatest advancement in fire protection in 30 years and believes that after proper testing, some trade-offs will be allowable.

Others have warned that home sprinkler systems installed that meet city but not fire association standards may not be eligible for insurance discounts.

Neither the U.S. Fire Administration nor the fire protection association could provide figures on the number of homes with sprinkler systems. Fire protection experts, however, believe the number of systems in use nationwide to be only about 2,000, with the bulk of those installed last year in the San Clemente area.

But Shaw predicted that within three to five years, what with cost savings and new technologies, most new residences will have the systems.

The next foreseeable advancement that could make home sprinklers more affordable would be the permission from the fire association and from Underwriters Laboratories to use plastic piping, which could save several hundred dollars in material and labor costs. That approval is expected within a year.

Also under consideration is a bill introduced by Sen. Howard Cannon (D-Nev.) introduced a bill that would give homeowners a 20 percent tax credit off the cost of installing home sprinklers.

The construction industry, however, still believes the cost of sprinklers is prohibitive. Even with Cobb County's trade-offs, which reduce the price of a system to $400 for a 1,000-square-foot apartment, builders there contend that the extra cost is higher than what the public will readily accept.