Eco living: how a 'Chimney Sheep' could keep your house warmer But would an inch-and-a-half-thick wad of felted wool shoved, with the use of a handle, part-way up a domestic chimney really save on energy bills and reduce draughts? Sally had her "Sheep" tested by Steve Sharples, Professor of Sustainable Environmental Design at the University of Liverpool's School of Architecture. "For older homes, having an unused open chimney is like leaving a window open all the time during winter months," says Prof Sharples. There are around 11 million pre-1965 houses and bungalows with chimneys designed to draw air up and out of a building. Potentially millions of pounds are spent on domestic heating that disappears up these outdated chimneys. After testing the "Sheep" in three-bedroom 19th-century end-of-terrace houses in Aberdeen, Liverpool and London, Prof Sharples calculated that it would save £74, £64 and £57 per year in each respective location. Considering the "Sheep" costs between £12.50 and £25 for standard chimney widths, that doesn't seem such a bad return. "The savings aren't enormous," says Prof Sharples. However, the cost of the Chimney Sheep is low so actually you get your money back in one cold winter. Equally importantly, by reducing cold draughts, it really improves comfort in old leaky homes. What I like about it is that it is low-tech. I'm fairly suspicious of so-called hi-tech 'eco bling. The "Sheep" has no controls, no levers but offers small, easy-to-achieve savings. I know people at this time of year are worried about their bills and wondering how to insulate their homes without having to spend a fortune. Getting the basics right: the standard funny animal draught excluder, checking seals on windows and front doors, topping up the loft insulation will all make a difference with little outlay. Sally is also helping Lake District hill farmers by buying their fleeces. She has used the fleeces from about 750 sheep so far and will to use more if her invention is a hit. "I've invested around £50,000 in developing it over the past few years," says Sally whose "Sheep" was shortlisted in this year's Green Economy Awards. We didn't actually go hungry but we didn't buy any new clothes for years. It has been a massive gamble, I had no idea whether people would get it or not. Sally has now been bitten by the invention bug and she is in good company. "As a nation we're fantastic at inventing things," says Kane Kramer, chairman of the British Inventors Society. Over 50 per cent of the world's manufactured products were invented in Britain. He puts it down to a cool climate, which certainly inspired Sally Phillips. Chimney Sheep