The National Trust in the UK, founded in 1895 by three fascinating people who worked on social reform in industrial England, looks after more than 500 historic houses and castles in England, Wales and Northern Ireland. It also cares for more than 250,000 hectares of land and more than 780 miles of coastline; and nearly a million works of art. 

And, while many of its magnificent buildings are drafty, and built long before energy efficiency became commonplace, the National Trust has been introducing climate friendly strategies that will save energy and money and move towards generating more of its power from renewable sources.

On the North Wales coast, where they care for a 300-year-old mansion, they installed Britain’s biggest marine source heat pump to provide 100 per cent of the heating needed by Plas Newydd Country House and Gardens.