How £7m 15-bedroom Tudor mansion with £100k-a-year energy bills now costs nothing to heat after novelist owner’s eco-retrofit

• It took Giles Keating, owner and economist, two years to eco-retrofit his home

A 15-bedroom Tudor mansion that once had energy bills of more than £100,000 a year now costs nothing to heat after an eco-retrofit.

Novelist and economist Giles Keating bought Athelhampton House in Dorset in 2019, for a reported £7 million, after he fell in love with the property.

However, the property’s energy costs already came in at about £55,000 a year, before the Ukraine-Russia war then quickly saw these double. 

The Grade I-listed country home had a high carbon footprint of 100 tonnes a year and was heated on LPG (liquid petroleum gas) and kerosene.

In a bid to make the property carbon neutral, Mr Keating removed all of the oil burners, gas ovens and boilers, instead opting for air-source heat pumps and large Tesla Powerwall batteries.

It took Mr Keating and architect Stefan Pitman two years and three quarters of a million pounds to eco-retrofit the home.

But the property now costs nothing to heat. 

Mr Keating told The Times that the heating was introduced over a five-month period and that every room in the large home can be heated up to 21 degrees Celsius, apart from the Great Hall.

Mr Keating said he controls the heating from his home and as a result of the retrofit, said the building has become a ‘lot better preserved’.

He told The Times: ‘We had some Tudor reenactment people stay the night recently in the four-poster beds and they couldn’t believe how comfortable and warm it was.

‘They did complain about the ghosts, but that’s just the way it is.’ 

Mr Keating spoke to homeowners of other historic estates for their advice on how to heat the home. They suggested biomass, wind turbines and hydro, but there were issues with all of these suggestions.

Now, 100 kilowatts of solar PV (photovoltaics) have been placed in a water meadow near the main house.

The design enables sheep to graze, while the heat pumps away underneath the ground, according to The Times.

Ten air-source heat pumps are hidden behind a yew hedge, with another five situated near the coach house. 

The house is now the warmest it has ever been in its entire history, it was stated in The Times.

The history of the Manor dates back to 1086 and the name Aethelham appears in the 13th century, when the house belonged to the de Loundres family.

It has become a popular tourist attraction, having been featured in the film Sleuth starring Michael Caine and inspiring the setting of Thomas Hardy’s classic novel Far From The Madding Crowd.