"It's recycled newsprint: it's 10 inches thick, you know, really well done. And there's triple-glazed windows. So you can sit next to the window in the middle of winter in a T-shirt and you won't be cold. And that allows us to really radically downsize the heating system," Thompson says.

The building does have great insulation — extra-great. Thompson says the exterior walls are several inches thicker than basic code would require.

"I know it had great insulation. I had to shut off my heat in February," Janes says. "It was too hot."

And, finally, it had to meet the needs of tenants like Peter Janes, who was one of the first to move in this winter.

Architect Jesse Thompson says the 45-unit project had to meet a lot of goals: Construction had to be cost-effective enough to get financed by public and affordable housing groups; it needed common areas and office space for Head Start and a community policing station; it had to be ultra, ultra-efficient.

The Bayside Anchor , a big, green, somewhat boxy-looking four-story building that overlooks a tidal cove in Portland, Maine, has joined the trend.

You may have heard about passive housing: residences built to achieve ultra-low energy use. Imported from Germany, it's been kind of a boutique-y thing here until recently, with eco-minded homeowners making costly upfront investments to downsize their carbon footprints. But now, New England is joining a surge in large-scale passive housing development.

There isn't a central heating system at all. Instead, each apartment has a small baseboard electric heater with an estimated electricity cost of just $125 a year.

There isn't a central heating system at all. Instead, each apartment has a small baseboard electric heater with an estimated electricity cost of just $125 a year.

It takes more than thick walls to achieve those energy savings. It also takes a near-perfect seal on the building's envelope and a high-tech ventilation system to purge moisture while keeping warm or cool air in, depending on the season. Thompson calls it the building's "lungs."

"So all the bad air, all the bad smells go out. But the heat stays in," he explains. "The fancy technical name is a 'heat recovery ventilator.' But they feel like magic to us."

There are other environmentally friendly features: a roof-full of solar panels, and underneath the ground floor's polished concrete slab, instead of a basement crammed with heating systems, big retention tanks allow rainwater to filter slowly into surrounding land, bypassing the city's overworked storm water system.

And all for a cost that's low for Portland's go-go development scene. Thompson said prices for high-efficiency materials and systems are dropping fast. And, he says, public housing agencies are beginning to embrace the long-term savings gained through lower energy and maintenance costs.

"Everyone is starting to see how the economics are working," he says. "They are giving extra points for meeting these energy goals. So we're going to see a big wave coming in the next five years."

A Treat For Southie Developers

It's reached South Boston now.

"I don't want to be embarrassing about this, but it's a kind of miracle," says developer Fred Gordon. On the site of a 19th-century waterfront rum distillery, Gordon is renting up the first apartments in what will eventually be a 65-unit passive housing building.

"I could stand and look at this building all day long. I just eat it up. It's like having a new girlfriend," he says.

Fred Gordon stands in his apartment at the Distillery North. (Jesse Costa/WBUR)

It's very much like the one in Portland: super-tight envelope, high-tech ventilation and no central heating system. But there's also an important difference. In this case, Gordon isn't relying on government incentives for affordable housing. He's going market-rate and plans eventually to sell the units.

In Southie's hot housing market, Gordon's got one advantage: He bought an entire city block there back in 1984, when land was considerably cheaper.

But he insists that the distillery project proves any developer can radically reduce a building's carbon output and still make a buck. Gordon says renters and buyers are willing to pay a 10 or 15 percent premium for passive housing features.

A view of the Distillery North from the rear looking from East Second Street where the old and new buildings adjoin. (Jesse Costa/WBUR)

"It's getting to the point where as an investment decision ... [it's] increasingly attractive," Gordon says. "That's what we want to do. We want to make it so that if a building is not a passive house, then people say, 'Oh, well, that's a real negative, I would rather do something that is a passive house: it's just better.' "

Officials at the Chicago-based Passive Housing Institute say it's still a big ask to finance market-rate units that won't realize full energy-efficiency savings for decades. But momentum for large-scale passive housing really did start gaining last year, when the number of buildings the institute certified doubled.

And that number is on course to more than double again this year, with projects getting bigger and bigger, including a 350-unit New York City high-rise.

This story comes via the New England News Collaborative, and was first published by WNPR.