Tom Potter had a steady construction job in New Mexico, but he didn’t like the way homes were being built.

“Nothing green, nothing efficient,” he said. “I said to myself, `There’s got to be a better way to build things.’ ”

After moving to Maine, Potter began his own green home construction business in Rockport. The first house he built to sell in-state included a handful of energy-efficient innovations, like designing the frame to need less lumber since wood is a poor insulator.

“The first thing we do, we go in there and take out any piece of lumber that’s not necessary,” he said.

The home easily earned an Energy Star label from the EPA. Energy Star homes must meet EPA efficiency guidelines; they typically require 20 to 30 percent less energy to operate than standard homes.

But Potter said area realtors were skeptical that the home would sell, that is until the first person who looked at it bought it.

“Drove up in a hybrid,” Potter recalled.

A new EPA report shows energy-efficient home construction in Maine is still the exception rather than the rule, and the state is lagging behind its neighbors in green housing design. The report found Maine had the lowest percentage among New England states of new Energy Star-certified homes in 2006. Vermont led the way with 24 percent of new homes earning Energy Star honors; Maine scored last with less than 3 percent.

Maine energy and construction experts agree the percentage of Energy Star homes in Maine is expected to rise, and affordable housing projects will lead the way. Since May 1, 2005, all home construction projects applying for public funding must meet the state’s green building standards. Major national lending institutions for affordable housing projects are requiring homes to meet Energy Star specifications, too, according to Liza Fleming-Ives, associate director of the Genesis Community Loan fund.

Three New England states, Vermont, Connecticut and New Hampshire, ranked among the national leaders in Energy Star home construction, the EPA report said. Energy Star homes must be at least 15 percent more efficient than homes built to the standards of the 2004 International Residential Code. The average Energy Star home can save homeowners $200 to $300 annually on home operation costs, according to EPA estimates.

Fleming-Ives isn’t surprised by Maine’s low percentage. She believes the state’s geography makes importing new construction innovations difficult. “There’s only one road in and one road out, really,” Fleming-Ives said.

There aren’t as many builders trained in green construction techniques as in other states, she said, and the extra cost of importing green home-building materials is prohibitive for affordable housing groups, especially on Maine islands.

“The thought of constructing a home that’s in any way out of the ordinary…it’s kind of hard for any of these groups to consider that,” Fleming-Ives said.

Maine’s and Vermont’s varied Energy Star scores also may stem from the differences between the two states’ energy-efficiency programs.

Vermont was the first state to create an energy-efficiency office, Efficiency Vermont, back in 2000, according to Paul Burns, executive director of Vermont Public Interest Research Group. Since then, the program has won over all critics.

“Nationally, they’ve been recognized as one of the best,” Burns said.

Efficiency Vermont offers multiple programs to encourage green home construction, including training, testing and financial incentives of up to $1,350 a home. In contrast, Efficiency Maine has been in operation for only three full years and has no home construction program. The organization has run a successful campaign, however, to install 1 million compact fluorescent lightbulbs in homes and businesses throughout the state.

Both organizations are funded by small surcharges found in monthly electric bills, but the difference in budget between the two is pronounced. According to the National Resources Council of Maine, Maine has the lowest surcharge per kilowatt hour in all of New England, less than half of what’s charged in Vermont. That means Efficiency Maine has a much smaller budget to work with, said Richard Bacon, program manager for Efficiency Maine.

“We’re a department of five,” Bacon said. “At one point, they had 160 people.”

But Efficiency Maine will soon expand its reach to provide help for efficient home construction and remodeling, said program manager Bacon. Currently, the organization is compiling a baseline study of existing home conditions in Maine. The organization will most likely enjoy increased funding from revenue generated by surcharges on power plants in Maine, thanks to the recently-ratified Regional Greenhouse Gas Initiative, according to Sara Lovitz, energy outreach coordinator for the National Resources Council of Maine.