Giles Keating used to have energy bills of more than £100,000 a year, but now it costs him nothing to heat his home.

The novelist bought Athelhampton House in Dorset in 2019, for a reported £7million, after he fell in love with the property.

With 15 rooms to hear, the energy costs were already about £55,000 a year and later doubled after the Ukraine–Russia war broke out.

But now the Tudor mansion, which is a Grade I listed property, has had an eco-retrofit, and it now costs nothing to heat.

In a bid to make the property carbon neutral, Mr Keating worked with an articetct to see what alterations he could make to the mansion to cut costs.

He 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 home was originally heated using LPG (liquid petroleum gas) and kerosene, which amassed a carbon footprint of more than 100 tons a year.

Each room can now be heated up to 21C. When first installing the heating, Giles and Stefan approached it one room at a time.

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

He said: “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.”

The house is now the warmest it has ever been in its entire history, the newspaper reported.

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.