Plas Newydd on the isle of Anglesey inWales is not a spot where one might expect up-to-date and sustainable heating systems. Built consecutively since 1470, the manor house with views towards Snowdonia and in the centre of a large agricultural estate was once home to the Marquises of Anglesey, before it came into National Trust ownership in 1976. It is always a challenge to keep such a building warm and – especially when important art pieces are involved – to maintain a good room climate. The manor house and parklands are a Grade I listed heritage site.