Built on a tilt: Snøhetta's Zero Energy House is completed in Norway
During construction we wrote that This house will generate more energy than it takes to build it, operate it, and charge the car in the garage. In fact, this house is built to what is probably the toughest energy standard in the world, tougher than even the Living Building Challenge. That's because it not only has to produce more energy than it uses, it has to repay the debt of all the energy it took to build, and that is embodied in the materials it is made of, amortized over the estimated life of the house. Now it's done, and our friends at Designboom have photos.
As I noted in my coverage of the first building made this way, that means no plastic foams and no concrete, both commonly used in green buildings.
In America, the plastics industry would go crazy over a standard like this; In each square foot of R-20 insulation, cellulose insulation embodies 600 BTU, Mineral wool 2,980 BTU, and Expanded polystyrene is 18,000 BTU (according to Martin Holladay at the GBA) The concrete industry, responsible for 5% of the CO2 emitted in the world, would be making cement overshoes.
© Research Center on Zero Emission Buildings
This kind of thinking is hotly disputed, with many designers claiming that the energy saved by using foam insulation more than compensates for its embodied energy. They wouldn't even bother doing this kind of calculation, which interestingly shows that the manufacture of the photovoltaics has by far the highest embodied energy.
This ain't no dumb home either, there is a lot of technology that has to be maintained over the life span of the house, some of which probably will have to be replaced at some point. I wonder if they take that into account in the calculation. Perhaps it is; according to The Nordic Page,
The goal of creating buildings that do not contribute to climate change is defined here in its most ambitious form: zero emission buildings must achieve a balanced carbon footprint throughout the course of their whole existence, including construction, operations, and demolition.
The architects did some of the most hyper-realistic renderings I have seen; it was hard figuring out what was real. I hope I have this right.