WORKINGTON, UK. September 22nd, 2026 – Chimney Sheep Ltd, maker of the Chimney Sheep wool chimney draught excluder, is celebrating 14 years since it was registered at Companies House.
In that time, 310,000 Chimney Sheep have been sold to households across the UK, and the company still hears from original customers whose first Sheep are going strong.
Using calculations by BSRIA, an independent laboratory, of how much a Chimney Sheep saves each year, the company has totalled the cumulative savings, counting each year of use since installation.
The total comes to 1,449,713,903 kWh of energy saved – heat that stayed in homes instead of going up the chimney. This equates to £48.4 million saved on heating and 343,443 tons of CO₂ which was never released.
That is roughly the energy needed to heat and power more than 120,000 UK homes for a year, based on Ofgem’s typical household use of 12,000 kWh, and the equivalent of more than 28,000 typical annual household energy bills at today’s price cap. The carbon saved is equivalent to taking 136,000 cars off the road for a year.
Over the last five years, Chimney Sheep has also donated enough money to Buy Land Plant Trees CIC to purchase 350 acres and plant 420,000 trees. The company has helped pioneer cluster planting, a technique that is not widely used but is effective for establishing woodland in upland areas by replicating the way nature works. Visitors travel from across the country to see it. Some of the trees are already producing seed or suckers, thereby replicating themselves and increasing the final number of trees.
Even if only half the trees reach maturity, that is 210,000 trees, each expected to absorb around one ton of CO₂ over its lifetime. Together with the carbon saved by Chimney Sheep, the total is over 500,000 tons.
Sally Phillips, founder and director of Chimney Sheep, said: “It’s not a sexy techy gadget. It’s a rather boring, deliberately simple, useful thing. But it is getting on with the job, one chimney at a time. It’s not just me anymore. It’s a team that includes Chimney Sheep staff past and present, customers, friends and family, donors, and the organisations that have assisted and facilitated. I’m proud of what we’ve achieved.”
An estimated 11 million UK homes have open chimneys, so 310,000 Chimney Sheep is a small share of the potential market. Around 80 cubic metres of air flows up an open chimney every hour. That air has to be replaced, which pulls cold air in through leaky parts of a building.
Sally Phillips added: “I developed the Chimney Sheep because I became aware of how much heat was being lost up open flues. It’s literally like leaving a window open permanently, and it seemed to be a colossal waste of resources.”
For 14 years, the company has campaigned to make draught-proofing a chimney as normal as draught-proofing doors and windows. This year, the Energy Saving Trust included draught-proofing the chimney in its top ten energy-saving tips, at number two.
Sally Phillips said: “While there are things to celebrate, there is plenty still to do.”
ENDS