About two thirds of UK homes have a chimney, a large proportion of which are left open. On average, one of these homes will lose 520 kilowatt-hours of energy through heat loss up the chimney. This equates to 185 kilograms of carbon dioxide, depending on the type of heating fuel used.
Chimney Sheep was the idea of Sally Phillips, who lives in Cumbria. One of her duties as a volunteer bat warden was to free bats stuck in people’s homes, the animals often having come down the chimney. This led her realise how many people leave their chimneys open, wasting energy, even though the fire is scarcely used.