Growth in awareness and soaring fuel prices have been cited as reasons for the surge in interest at the open day by Richard Acheson, spokesperson of the Carvill Group, that developed the range of houses.

He said: “We have built over 1,000 eco-homes in Northern Ireland, but it is only in the last three months people have really bought into what it means.

“They are now aware of renewables and the impact on their pocket.”

Houses on the Woodbrook estate are heated by locally-grown willow, which is some 60 per cent cheaper than heating oil.

Energy efficient boilers and high levels of insulation are also among the environmentally-friendly features of the properties.

Meanwhile, an eco home known as Orchid House has recently sold for £7.2 million.

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