Much has changed since the birth of the nation’s first suburb, but the boilers in many of the original Cape Cod and ranch homes in Levittown haven’t. Chalk that up as an opportunity for residents to start saving on their energy costs, say Nassau County officials and environmentalists.

Starting in January, Nassau is launching a program called Green Levittown, in which residents of the 17,000 homes in the town will be offered low-interest financing, discounts on home improvements, and as much as $3,000 in rebates from the Long Island Power Authority to retrofit their homes with energy-efficient equipment.

The goal of this program is to reduce carbon emissions in Levittown by 20 percent in 2008. If successful, the program could be expanded regionally, if not nationally.

Green Levittown is perhaps the most aggressive program amid a growing list of energy-saving initiatives by municipalities across Long Island, including efforts in Great Neck, Babylon, and other communities.

So, in the example of the boiler, if you decide to foot the $4,000 to $5,000 bill for a new one, what would it get you?

A lot, says Brad Tito, deputy director of environmental coordination for Nassau County Executive Tom Suozzi. “If you replaced it with a modern, Energy Star boiler, you could save 300 gallons of oil a year.” That translates to about $900-plus a year considering today’s rates for a gallon of home heating oil.

Why Levittown? Aside from the symbolic value of creating another suburban “first,” it helps that the town has a uniform housing stock. That gives participating companies a good idea what they should expect and plan for at the start, Tito said.

To get the word out, Nassau enlisted the help of energetic environmentalist Adrienne Esposito, executive director of Citizens Campaign for the Environment.

Esposito will bring on as many as 12 canvassers to knock on every door in Levittown. The crew will make energy-saving recommendations, offer home energy audits, and present special offers on energy-efficient equipment, appliances, and products. All the information will be available on www.greenlevittown.com.

Nassau officials stress that the program, which they believe promotes “easy environmentalism” since it doesn’t require residents to make major changes in their energy-consumption behaviors, is funded entirely by participating companies at no cost to Nassau County taxpayers. (Stan Bratskier of public relations firm Blue Wolf Communications, which is coordinating the entire effort, said he couldn’t release the amount of the amount without contacting each of the partner companies.) Those companies include Alure Home Improvements, Bethpage Federal Credit Union (BFCU), Earthkind Energy, Intellidyne Inc., Lazard Ltd., Long Island Power Authority, National Grid and Tragar Oil Co., and Satco Products Inc.

BFCU is providing low-interest financing for residents who want to take out a home-equity loan or line of credit to pay for home improvements under the Green Levittown program, while Satco is donating 20,000 compact fluorescent light bulbs that will promote the names of all the project’s sponsors.

The vast majority of the bulbs, 17,000, will be handed out at an Earth Day celebration; the remaining 3,000 will be given to Levittown homeowners.

The home-energy audits, which evaluate everything from a house’s insulation to the efficiency of the light bulbs you’re using, will cost “substantially less” than the current rate of $300, though the actual number is still being worked out, Bratskier said.

In the end, “The idea is to get 5,000 homes to participate in some way,” said Esposito.

“Actions that would count include getting an energy audit, insulating attics, weatherizing windows, or purchasing Energy Star appliances.”

“We believe we can do it."