Would you pay £36,000 extra for your next home if you knew it would cost just £1 a day to run?
Packed with energy-saving gadgets including the latest- technology solar panels and intelligent temperature controls, some new "eco-homes" have ultra-low running costs.
And, for that reason, they sell at a hefty premium.
Energy-saving properties are cropping up across Britain, typically in small, newly-built developments. Some have virtually no running costs.
Currently 11pc of UK homes are rated highly energy-efficient, achieving an "Energy Performance Certificate" rating of A or B. This is double the number of four years ago, according to the Department for Communities and Local Government.
But the Government's support for renewable energy devices, including solar panels and energy-efficient measures, are falling (read on for further explanation).
One couple who narrowly escaped the cuts are Graeme and Zoe Bidmead, both teachers from Lincolnshire, who say they have cut their energy and water bills to under £400 per year - or just £1 a day.
The house generates much of its own energy through solar photovoltaic cells installed on the roof.
The couple receive "feed-in-tariff" payments for the energy these panels generate and return into the grid, which is offset against all their energy spending.
The £1 per day figure "includes all our water and energy use", said Mr Bidmead, who moved in this August with his partner, Zoe, and their two dogs, Sampson and Charles.
Rainwater from the property's sloping roofs is harvested in tanks and used to flush the toilets.
Ultra-efficient glazing, however, means there is little need for additional heating.
"We haven't yet turned on the heating even once," said Mr Bidmead, "as the house is practically airtight."
If their £1-per-day costing proves accurate over time, they are saving almost £1,000 per year compared to the average household.
By comparison, the typical duel fuel energy bill in a three-bedroom family home costs upwards of £1,200 a year, according to official figures. This does not include water bills.
Families like the Bidmeads are also protecting themselves against future rises in energy costs.
However, the cost of buying a house with advanced technology adds up to 20pc to the property price, experts say.
The Bidmeads bought their three-bedroom, Lincolnshire property for £365,000 around 10pc above the cost of buying a similarly-sized property in the region.
"We definitely paid a premium," Mr Bidmead said. "It's a three-bed terrace and quite expensive for the north of England. If it were an ordinary property we probably could have added extra bedrooms.
"We didn't think of buying an eco-home before we viewed the property, but now I doubt we'll ever move."
= Solar panels: still a good investment? =
Subsidies for solar panels will shrink in the new year, meaning lower returns for people who produce their own green energy in the home.
Feed-in-tariff rates will fall to just 4.39p per unit for new solar panels from January 15, while costs are expected to remain static.
Panels installed before that cut-off, including those used by the Bidmeads, are eligible for payments of 12p per unit of electricity generated and used in the home.
However, the price of panels is falling.
Solar panels now cost around £6,800 for a typical 4kW system, down from £8,400 three years ago, according to the Renewable Energy Consumer Code.
But state-backed incentives to promote solar panel take-up, introduced in 2010, have become considerably less generous in recent years, as the chart above shows.
Energy experts have warned that the reforms could deter homeowners from undertaking new installations.
However, homebuyers are willing to pay a £2,000 for a home equipped with solar panels, on average, research by Barclays Mortgages suggests.
"Solar is still worth the cost if you consider wider benefits, such as the increased value to your home," said Paul Barwell of the Solar Trade Association.
"Homeowners can also benefit by changing the way they use the electricity they generate, for example by storing it."
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