This hi-tech home creates more energy than it uses. But what's it like to live in – and how does that touchscreen work?

Imagine a house so advanced and eco-friendly that within 40 years it will have fed more energy back into the national grid than was used to build it, wiping out its carbon debt to the planet.

For the past seven months, Sverre and Sophie Simonsen and their three children have been living in the world's first Active House – a sleek, angular building outside Aarhus in Denmark. It's one of seven being built across Europe by different architects – it will be joined in the autumn by an equally green semi in Northamptonshire. For 12 months, a family will occupy each home while the building's performance and the family's experience are monitored.

Sverre had been itching to move from their 1970s home. "It's a typical suburban Danish house with small dark rooms," he says. "I'd always wondered what it would be like to live in a contemporary, open-plan building." Their old home is only 400m away.

Light fantastic Glass features heavily in the £500,000 design, by Aart Architects for VKR Holding. "The natural light has definitely made a difference to our mood," Sophie says. It has twice as many windows as an average house, all triple-glazed with super-insulated frames. This is in contrast to most eco homes, where large windows on all but the southern facades are frowned on due to the material's poor insulation.

Double glazing: The Active House has twice as many windows as an average home. Photograph: Michael Franke

In winter, solar radiation streaming through the windows provides 50% of the heating, while in summer it is restricted by an automated system that controls sunscreens and opens windows. With the family's feedback, the pre-set programmes have been tweaked. "It got very hot last summer, and it was so bright you needed sunglasses in the kitchen," Sophie says. Privacy also proved a problem, because the perforated screens offered little respite from passersby. "They could see what we were having for dinner," she says. They would occasionally open in the middle of the night, too; they are now manually operated.

Technical hiccups Getting to grips with the lights that automatically turn off when sensors detect no activity was equally interesting. "If you've been sitting on the toilet a little too long, you're suddenly plunged into darkness," Sverre says. "And we had to install bedside lamps for the children as their lights kept turning off during bedtime stories."

The ­computerised control panel d­isplays how much energy and hot ­water the house is producing. Photograph: Michael Franke

Trial and error The computerised control panel, which displays how much energy and hot water the house is producing and consuming, looks fiendishly complicated. "The blinds and windows are numbered differently, with no diagram, so at the start it was trial and error," Sophie says. "But once you've figured it out, you don't have to understand the technology – you just turn it on and type."

Solar power The southern facade of the roof is pitched at 35 degrees to maximise solar gain, and coated with solar cells and collectors. The cells generate electricity for the lighting, appliances and the control system. They should produce 5,500kW a year – nearly double the amount required by the family – so for eight months excess energy is fed back to the grid. This means that, in winter, extra energy is provided from the grid for free.

The solar collectors provide more than 50% of the hot water and, combined with a solar heat pump, power the underfloor heating. There's also a ventilation system, which takes heat from stale air being extracted and uses it to warm fresh, filtered air entering the home. Most impressive of all, this energy balance is achieved without the family living a monastic life: the house has two flatscreen TVs, a kitchen crammed with Siemens and Gaggenau appliances, and a double shower. "You don't feel you're making sacrifices," Sophie says. "We use less energy without thinking about it."

The future In five months, when the house goes up for sale and the squad of technicians dissipates, the Simonsens will move back to their 70s home. They aren't putting in an offer, not because they don't enjoy the life, but because with cutting-edge technology the cost and hassle of finding someone to fix it is too high. Pioneering houses such as these demonstrate how green we can be. But only once the technology becomes mainstream and the workforce is trained to install and repair it, will homes such as this become a fixture on our streets.