A SOLAR kettle, a toilet fed by a wash-hand basin and an eco-friendly 'bum gun'.

These are some of the environmental adaptations one Oxfordshire family have made to their home which they showed off to visitors at an open day.

The Williams family of Stanford in the Vale, near Wantage, also impressed visitors with a freezer they turned into a money-saving, energy-efficient fridge.

Pat Williams, who shares the house with her husband John and their daughter Zoë, said: "People were really interested and we met some really interesting people."

One of the top attractions at the open day, she said, was the family's "bum gun": an energy efficient spray in their bidet which saves water and toilet paper.

Another was their ever-popular 'grey water' toilet and wash-hand basin combo.

She explained: "We have a small toilet and a basin made of recycled cooper on top of the cistern.

"When you flush the toilet, fresh water from the mains comes into the basin to wash your hands then that grey water goes into the cistern for the next flush.

"People love that."

But perhaps the most eye-catching contraption of the day was the Williams's outdoor solar kettle.

The metal-lined box opens up and is placed facing the sun: a transparent container like a thermos flask is then placed in the middle full of water and rapidly heats to more than 100 degrees.

Zoë Williams explained: "Fireless cooking saves around 40-50 per cent of the fuel.

"You can use anything insulating to make a fireless cooker – we made ours from a cool box and towels.

"You can prepare a soup as normal then as soon as it reaches a good boil, put the pan into the fireless cooker and it will continue to cook with no further input of energy."

Mrs Williams added: "It's actually quite impressive."

The family bought their 1958 bungalow in St Denys Close in 1987 and started experimenting with energy-saving adaptations.

Mrs Williams said: "It was partly wanting to set the house up to be as economical as possible but also wanting to reduce our carbon emissions.

"The first thing was an energy-efficient washing machine and over the years one thing led to another.

"When our old heating system broke down we wanted to move away from oil so we went to biomass – wood chips."

The Williams family opened their home as part of a nationwide SuperHomes event.

SuperHomes are defined as older homes refurbished for lower bills and, in this case, 93 per cent lower carbon emissions.

Visitors also admired the Williams's triple glazing, rooftop solar panels and their electric car.

Find out when their next open day is at superhomes.org.uk