THE LURE OF THE ‘NIL-BILL’ HOME
Woodchip boilers, bio-digesters and boreholes are increasingly sought after, as agents report a shift in attitudes towards energy efficient houses. Caroline McGhie investigates
Stephen and Anne Mullins used to ride their bikes onto the Hampshire hills above Winchester and sit on the grass by an old semi-detached farm cottage to admire the view. When the cottage came up for sale they bought it and laid plans to build one of the most energy-efficient houses in the country, an exhilarating barrel-roofed structure which costs £3 a day to run. By day Stephen is a project director involved in building Terminal Two at Heathrow, which will cost around £3billion. But at night he returns to his children Beth, 15, and Wills, 14, and the pleasures of the house created with his wife Anne and local architect David Gregory. It is one of a tiny number of new houses to achieve an Energy Performance Certificate (EPC) top A rating. The Barn House draws energy from the ground using a ground-source heat pump which extracts warmth from the earth through a labyrinth of underground pipes. “We also have photovoltaic panels which use solar energy for the electricity, solar thermal for the hot water, and a heat recovery system which is constantly taking out stale air, bringing in fresh air and heating it,” says Stephen. Half the electricity is sold to the National Grid. The house works like a mini ecosystem. Sewage goes into a bio-digester. “In our old house we had a septic tank, and a lorry came to take away the sludge. The bio-digester bubbles air through the sewage-soup and breaks it down so the water which runs out at the end is completely clear.” There are underground tanks to collect rainwater for reuse. “At any one time I can see how much water, electricity and solar power we have used. We have to live a bit differently to catch the photovoltaic energy during the day, so we always put the dishwasher and washing machine on before it gets dark. It is a good way to live because you control your environment.” Though the family love the house, they are selling through Knight Frank (01962 850333) at £1.2million. “We have got the bug and want to do an underground house next,” says Stephen. Individuals rather than developers appear to be the true prophets of green technology. Nick Price was a Sustainability Code assessor and became so interested that he built two energyefficient houses in Winchester which attained Sustainability Code 5. The top level is Code 6, which very few reach. Then he bought a run-down artist’s studio and garden, near where he lives in Bury St Edmunds, to go one stage further. He demolished the studio and built Evergreen House with a system of super-insulated panels and a flat roof. “I put in lots of triple glazing on the south side, made it airtight with a combined heating and ventilation system which extracts stale air and heats fresh air. It keeps the house in perfect balance, so there is no need for radiators.” They have a log burner for when it gets cold and a little underfloor electric heating in the barefoot areas but that’s all. Solar panels heat the hot water and the house makes enough electricity to pay its own bills. Bedfords (01728 454505) is selling it with an EPC top A rating at £550,000.