In Maine's cold-weather climate, it might seem like an impossible task to design a house that requires almost no heating, but this is what a firm of mid-coast architects is doing. G-O-Logic in Belfast is putting the finishing touches to a prototype dwelling that looks on the surface like a simply-designed, three-bedroom, 1,500 square foot family home with a peaked roof on about an acre of land. But this is no ordinary house: It's about to be approved as Maine's first so-called "Passive-House" certified home -- and indeed one of the few to be found in the Northeast.

"A passive house is a house, really, that takes care of itself," says architect Matthew Omalia. Omalia says passive houses are models of energy efficiency, designed to maximize the heat offered up by natural sunlight and retain that warmth. For most people's energy needs, he adds, they require very little input to be comfortable.

"To give you a little perspective, the amount of heat that's necessary to warm the building in the middle of January in the middle of the night is that of the output of a hairdryer," Omalia says.

As he took me on a tour of the nearly-complete house (pictured above), Omalia explained why passive houses so efficient. Probably the biggest factor, he says, is insulation. The structure features no what he calls "thermal bridges" -- that is to say objects which are on both the outside and the inside of the building.

The external doors for example each have three air seals, and look like they wouldn't be out of place in a bank vault.
The tripled glazed windows, imported from Germany, are also state-of-the-art, says Omalia.

"Their air-sealing is really quite fantastic," he says. "They have a multi-gasket on all the openings for the doors and windows, which really ensures that there's no air filtration through these things."

WIth all this insulation, you may be a little concerned about constantly breathing in the same stale air. No need to worry about that, says Omalia's business partner Alan Gibson, who's been building "green" houses in the mid-coast area for 20 years.

"When you make a house this air-tight then you have to have some way to mechanically provide fresh air," he acknowledges. "So we have a heat recovery ventilation system that is adducted to different parts of the room. It takes out stale air and brings in fresh air and it goes into this box where the heat from the outgoing air is transferred to the incoming air, therefore you don't pay a big penalty for re-heating that fresh air."

Omalia and Gibson say they're on course to meet the rigorous standards required for certification by the U.S. Passive House Institute based in Illinois, which was set up three years ago as an offshoot of a technique already well-established in northern Europe.

"It was a great challenge to try and do a passive house in this climate," Omalia says. "It's very, very stringent. It's based on a German energy standard, and the German climate is much more mild than Maine. We have much colder days in the winter time, but we also have a lot more sunshine in the winter."

And it's the heat from this sunshine which pours in through the six-foot-by-six-foot windows. This heat, says Omalia, is absorbed by the house's concrete floors and radiated through the house, an effect he describes as being like a big "thermal battery."

And to keep the warmth from escaping through the foundation, there are polysterene insulation blocks underneath and around the building.

The house is not completely self-sufficient, but still only requires about 10 percent of the energy used by an average conventional home -- something which puts it in line with the U.S.'s 2030 climate change goals 20 years early.

As well as being good for the environment, says Omalia, passive houses are good for the wallet -- especially in a state like Maine, which has old housing stock, nearly all heated by oil.

Working on the basis that the average household spends about $2,000 a year on heating costs, and that the price of oil doubles every 10 years, the home-owner can expect significant savings. "When you take all that into consideration you can save up to around $200,000 with a house like this over a 30-year mortgage," Omalia says.

And given that this 1,500 square foot dwelling will probably be priced at about $225,000 when it goes on the market, the anticipated energy savings mean it will almost pay for itself over the life of a mortgage, says Omalia.

This model actually takes the energy-saving concept a stage further by having solar panels on the roof. Solar panels are not required to receive passive certification, says Alan Gibson, but they do mean that when the sun is shining, you're putting power back into the grid.

"It actually feeds the neighbors' houses, and then goes on from there down the line," Gibson says. "So we have two meters here, one meters the energy that's coming in, one meters the energy that's going out, and at the end of the month, if we've produced more than we've used, then it gets credited to our account."

Examples of passive house design have started to spring up across the country, says Kristen Bacorn. She's a New York-based architectural consultant, specializing in environmentally conscious design, who's currently working on a passive house project in Brooklyn.

"I have been telling my students for years that you don't necessarily want all these sexy, exotic technologies," she says. "The first thing you do if you're going to go green is conserve."

Reached by cellphone, she says she likes the simple concept behind the passive house. "Then the second thing you do is go with all the bells and whistles of technology. So what I like about the passive house is that in many ways, it's sort of a low-tech solution."

Meanwhile back in Belfast, the prototype home is expected to be ready and habitable this summer. Matthew Omalia and Alan Gibson at G-O Logic plan to use it as the model for a 36-home settlement, known as a "Co-Housing and Ecovillage" to be situated on a 30-acre site near Belfast. Although these homes have yet to be built, Omalia says they've already heard from potential buyers for 27 of the units.