SOUTH PORTLAND — Fire chief Kevin Guimond says there are lots of good reasons every new home should be required to have a sprinkler system.

Insurance savings. Higher long-term home values. Far less damage in case of a fire.

But in the chief’s mind, the ongoing national and statewide debate about mandated residential sprinklers begins and ends with safety.

“They save lives,” said Guimond, who has proposed an overhaul to the city’s fire protection ordinance this year, including a provision that would require sprinkler systems for all new residential construction.

“You have a far greater chance of getting out of a house on fire with an alarm and with an operational sprinkler system. My job is to protect you from fire. I’m very comfortable promoting it because I think it’s the right thing to do.”

While no one disputes the safety impact, there’s plenty of opposition to the legislation of sprinkler systems.

Homebuilders, real estate agents and banks have opposed such requirements for years. Those trade groups argue that the up-front costs — generally $4,000 to $10,000 for an average-sized new home with a full basement — puts homeownership out of reach for many families. Advances in smoke detectors have made homes safer than ever, they say. Others oppose sprinkler requirements purely on the basis of individual property rights.

“How far can the government go into our personal property? I think they are crossing the line here,” said Gary Crosby, a commercial real estate developer from South Portland who has been active in civic affairs for more than a decade.

“Their name is not on the deed. If I own it, and I want to take the chance of not having a sprinkler in my house, that is my choice,” Crosby said. “Commercial property is a different issue. I think requirements are appropriate there. But with a single family house I think you ought to keep your hands off.”

The City Council is expected to take up the issue later this summer. The rewrite of the fire protection ordinance would require two votes by the council and a public hearing.

If South Portland mandates sprinklers for new homes, it would join Portland, Westbrook and Rockland as the only municipalities in the state with such a requirement. All of those ordinances were adopted in the past two years. Several other communities, including Gorham, Falmouth and Sanford, have limited ordinances that require sprinklers under certain circumstances, such as new homes in subdivisions that do not have water sources for fire departments. Scarborough’s fire chief supports a mandate, but he has not brought forward a formal proposal to town officials.

These local efforts are part of a nationwide debate that has been going on since the mid-1980s, when Scottsdale, Ariz., became the first major city to mandate sprinklers in new homes. The trend spread from the Southwest to other parts of the country.

In 2006, as part of the building safety codes that it revises every three years, the National Fire Protection Association called for requiring sprinklers in all new single-family homes, duplexes and nightclubs with a capacity of more than 100 people. The International Code Council followed suit with a similar change to its standards in 2009.

Legislatures and municipalities generally look to the NFPA and ICC as models for state and local laws.

Only two states, California and Maryland, have adopted the sprinkler requirement. Lawmakers in Maine adopted most of the NFPA’s life safety code, but they have left the decision on sprinklers up to individual communities.

Now that Portland and Westbrook have ordinances on the books, and South Portland is considering the requirement, industry experts say more towns and cities in Maine will likely follow their lead.

“In the last two years, we’ve probably installed systems in 25 or 30 houses in Westbrook and Portland and Falmouth, where before that it was maybe one or two a year,” said Scott Garland, supervisor of the Portland office for Sprinkler Systems. The Lewiston-based company installs sprinkler systems for commercial and residential customers throughout northern New England.

“It really started taking off when Westbrook started requiring it,” Garland said.

Garland, who has worked in the sprinkler industry for 26 years, said the local fire departments and code enforcement offices have led the push for the sprinkler mandates. The average homebuyer in Maine generally is not asking for the extra protection, he said.

“There are people out there who don’t want sprinkler systems in their houses. People get upset that they have to do it,” Garland said. After the systems are installed, he said he has never received a complaint about them.

“A lot of it is education. People think they are going to burst or just go off on their own, and that just isn’t the case,” he said. “These systems are very reliable.”

Residential sprinklers are designed to quickly douse flames before they spread, slowing the advance of the fire or extinguishing it altogether. Sprinkler heads are individually activated and pump about 10 gallons per minute in a fine spray, less than one-tenth the amount of water sprayed from a fire hose.

Rob Sherman, owner of Hallmark Homes in Topsham, is a board member of the Home Builders and Remodelers Association of Maine. He’s also the national director of the Modular Home Association. Both groups continue to oppose any government requirement for sprinkler systems in new single-family homes.

Sherman said advances in smoke detectors and electrical codes deliver enough safety, and a decision to add another layer of protection should be left to individual homeowners.

“How can we put that onus on first-time homebuyers, or people who have outgrown their homes? The cost of a sprinkler system, for many people, puts the dream out of reach,” he said. “They are not putting extras in their homes, and they are already stretching themselves thin.”

It’s hard to estimate costs of a sprinkler system because every home and lot are unique, and there are different types of systems on the market. Garland said a customer building a typical two-story home, at 2,000 square feet, tied into a public water supply, can expect to pay $4,000 to $4,500. For a new home that is not connected to public water, a tank and pump sprinkler system would add another $3,000 to $3,500, Garland said.

Eric Ellis, the fire protection engineer with the state Fire Marshal’s Office, agreed that most systems for a new home end up costing $5,000 to $10,000.

He said that’s a wise investment from a life-safety perspective and from an economic perspective.

“The record for home fire sprinklers is phenomenal for saving lives,” Ellis said. He licenses the industry in Maine and issues all the fire sprinkler permits in the state, from 400 to 800 annually in recent years.

Ellis said there are several potential sources of cost savings when installing a home sprinkler system. The need for firewalls and other fire-resistant elements is reduced or eliminated, he said. Insurance companies offer discounts on premiums, generally ranging from 5 to 12 percent per year, for sprinkler protected homes. Developers can find savings, too, Ellis said. Municipalities generally allow longer dead-end roads, smaller turnarounds, more units and other trade-offs in subdivisions where the homes are built with sprinkler systems.

In the mid-1990s, Ellis said he issued one or two permits each year for a residential sprinkler system.

“Last year, one out of four permits I issued was for a home,” he said, noting that the permits were in more than a dozen towns. “We’re finding that people are putting them in when they don’t have to.”