The house does not need a furnace to stay warm through the winter. It is heated by a television, a toaster, a computer, AC adapters, light bulbs, steam from the shower and a hundred other things many people have in their homes.
Nabih Tahan, the home owner and architect likes to point out, "When you put your hand on the side of a computer there's hot air coming out. Every time you boil water, when you cook, the refrigerator, all these things make heat, besides doing the job that you want them to do. It's free heat!"
But, heat is lost when windows and doors are opened for fresh air. Nabih Tahan doesn't need to do that.
He ventilates his home a new way.
Hidden vents draw out the stale air and other tiny vents blow in fresh air. Although, one might wonder how the heat stays in.
The secret is a little black box in the attic. As warm indoor air passes through on its way out, cooler outdoor air passes through on its way in. The box exchanges the heat, moving it from one to the other. So, air circulates but warmth stays in the house.
It is called a Passive House, and it is a new European standard for new construction. Tahan claims the first remodel in the United States that meets that standard.
During construction, the house was hermetically sealed. Special caulk sealed every crack and window. Instead of 2 x 4 studs every 16 inches, 2 x 6 studs separate the walls every 24 inches. There is even insulation between the foundation and wood, and an air gap in all the siding.
"Normally," says Tahan, "we blast heat through our homes just to keep up with what's leaking out. This house doesn't lose energy, so it stays at this comfort level the whole year through."
Tahan architect has formed a special interest group in Berkeley and plans to prefabricate passive houses for construction in the US.
By the way, the average PG&E bill for the Bay Area is around $115 a month for electricity and gas.