House warming

The world’s first zero carbon emisson house lives in Denmark. The Active House, as it’s called, was developed to be a more comfortable and user-friendly response to the Passive House, which has set the standard for sustainable living in the last decade. Passive houses rely on incredibly effective insulation, plus a heat exchanger that warms fresh air on the way in during winter. A true Passive House has no conventional heating system because, in theory, it doesn't need one. In practice, owners tend to install back-up systems, because it's no fun even to risk being cold.
Rikke Lildholdt, project manager for the Active House, says "This is about living a comfortable life in a house that produces more energy than it uses."
Solar panels warm underfloor heating. Fifty square metres of solar cells generate electricity. Computer-controlled windows automatically regulate internal temperature.
British journalist Andrew Purcell doesn’t believe his eyes. In The Guardian he writes: “This is the last place you would expect to find the solar-powered home of the future. Lystrup, a suburb of Denmark's second city, Aarhus, is grey from street to sky. The spring sun, hidden behind a bank of clouds, barely seems strong enough to run a pocket calculator, let alone meet the energy needs of a family of four. But it is here that a dream of zero-carbon living is being realised.”