OPINION: The Model Home of 2020 will be self-sufficient by producing more energy than it consumes . . . Occupants should have no utility bills

IT MAY LOOK like just a well-designed dormer bungalow but the Model Home 2020 in Lystrup, 10km north of Århus in Denmark, is a trailblazer for the future - a climate-neutral building that optimises daylight, fresh air and indoor comfort all year round. It's also the first of six such model homes to be built in Europe.

Pioneered by Velux and Velfac, it will produce more energy than it uses through the solar panels incorporated into its south-facing slate roof, "exporting" the rest to the Danish grid or using it to charge the battery of an electric car. That's what makes the Model Home 2020 an "active" rather than a "passive" house.

Velux founder Villum Kann Rasmussen used to say: "One experiment is worth more than a thousand expert assumptions." And the performance of this model home is being put to the test by a local family - Sverre Simonson, his wife Sophie and children Axel (9) and Anna (6) - who are spending a year living in it.

It's both a home and a laboratory of sorts, and the Simonsons are the "guinea pigs", as Sverre, a 40-year-old chemical engineer, puts it. They were among 25 families in the Århus area to volunteer for the project. They moved in just two months ago.

There's been "huge media interest" and Sverre briefs visting journalists and gives them tours of the generously proportioned 190sq m house. Apart from the time taken up by this task (which was part of the deal), the only downside he identifies is "everyone can look in the windows" because they have no curtains. Although the rooflights are fitted with motorised blinds which protect against solar gain in summer and heat loss in winter, the large windows of the kitchen and livingroom are bare. These are bespoke triple-glazed windows with a specification higher than any previously produced, which makes them hard to price.

The experimental house, designed by Aart Akitekten in collaboration with consultant engineers Esbensen Rådgivende, cost four million Danish kroner (around €540,000) to build - significantly more than the average price of a family home in Århus, Denmark's second largest city. "I wouldn't be able to afford it," Sverre says candidly.

The glazed area is twice as large as a traditional low-energy house, flooding it with daylight. Solar collectors built into the roof produce both heat and hot water as well as powering the motorised blinds, while an integrated energy management system looks after pretty well everything.

Fresh air is drawn inside during the heating season by mechanical ventilation, which uses a heat exchanger to raise its temperature. Outside of the heating season, fresh air can be drawn in by natural ventilation controlled by automatic indoor sensors. The temperature in each room can be also adjusted independently.

The main objective is that the Model Home 2020 will be self-sufficient, in energy terms, by producing more than it consumes. Its promoters say the annual surplus will even pay back the embodied energy in all the materials used to built it within 40 years. And in the meantime, householders should have no utility bills.

The project is being supported by the municipality of Århus, which aims to become "carbon neutral" by 2030. And since buildings account for up to 40 per cent of all carbon dioxide emissions, one of the priorities of its multi-annual climate plan - Århus CO2030 - is to make them much more energy efficient.

Velux and Velfac, through their VKR joint venture, have no intention of mass-producing model homes; they intend the six being built will serve as demonstration projects to show what can be done. Ultimately, the Lystrup house will be sold, after the Simonsons move back into their old home 300 metres away.

"The most important thing is to make a house for people. That's why it's called a Home for Life," says Ellen Hansen, project manager for Velfac. "This should be an inspiration . . . We want to give a kick to the [ building] industry to do something better."

See velfac.dkm or velux.com for more details