Think of a large Thermos, large enough to put a family in. That’s a passive house. Passive houses are buildings that rely on their construction, insulation, and the environment to heat them in winter and cool them in summer.

They’re popular in Europe, but there are only a handful of them in the U.S. and one of them belongs to a family in upstate New York, who are getting ready to take on their first winter in their passive home.

The architecture is based on formulations that take into account body heat, steam from the stove, warmth from the washer and dryer, and even the lighting to replace conventional heating.

All the efficiencies, which result in the home using 90 percent less energy than a normal house, are achieved through some serious insulation and other features of construction like triple plated windows.

Chris Gould moved into his newly-built passive home in upstate New York less than a year ago with his wife and two kids.

And, as the temperatures drop, Gould says he’s not worried about facing winter without a heater.

“It’s amazing and it’s a very pleasant house to live in and we have in fact lowered our energy bills very dramatically. I think our total electricity bill, and the whole house is electric, have been about $100 a month, $100-120 a month, so it does in fact work.”

Greg Pedrick from the New York State Energy Research and Development Authority, NYSERDA, is part of a team that’s been studying the efficiency of passive homes.

He says they’re definitely a better, more efficient option. But it’s likely to take a while before they’re widely adopted in the US.

“We have data that shows it’s better but people don’t change quickly and it is not fully understood. So it’ll become a better movement with more owner education.”

And, Pedrick says most home buyers don’t completely grasp that concept.

The upfront costs of building a passive home may also be a stumbling block, he says.

Initial costs are higher than a normal house, but there’s no need to purchase a furnace, and the long term cuts in energy bills repay the investment.