AS OUR environmental awareness increases, many of us are prepared to insulate our loft or to invest in low-energy light bulbs. Other people – such as Colin and Pauline Ives, pictured – take a much more radical approach. They are building their own green home.

The couple found a suitable builder in Millwood Designer Homes – the first housebuilder to be assessed as “carbon neutral” (in that they buy carbon credits to offset the emissions from their head office and company cars) and the first to offer a service in which clients design their own home, adding whatever eco-friendly measures they wish.

Impressed by Millwood’s environmental credentials and the quality of their homes, the Ives and their teenage sons took to the drawing board last September. Wall insulation and double-glazing are standard in Millwood homes, but Colin ruled out solar heating because he felt it would take more than a decade to pay for itself. He also rejected a wind turbine because he expected planning approval to be slow. However, three eco-friendly measures are being installed in the Iveses’ five-bedroom house in West Malling, Kent.

The first, rainwater harvesting, cost £4,250 but Colin sees it as a must: “It’s surprising how much water you collect, and how much we all waste: 25 per cent goes just on flushing toilets.”

An underground heat pump (£13,000) absorbs heat from the Iveses’ garden and then extracts it to provide hot water and underfloor heating. “It’s fantastically efficient,” Colin says. “The pump should last 20 to 25 years but we expect it to pay for itself within eight or nine.” The energy required to run the system produces three to four times as much energy in useable heat. The Iveses were helped by two grants for the system: £1,500 from npower and £1,200 from the Government’s Low Carbon Buildings Programme.

The final measure is a heat recovery system (£7,250) which uses warm air generated in the kitchen and bathrooms to heat incoming air. “The Iveses are unusual,” says John Elliott, Millwood’s managing director. “Most buyers aren’t ready to pay a large amount of eco-cash that takes years to repay.” He believes that the underground heat pump is too costly to install in the company’s standard houses, but he predicts that rainwater harvesting will be in all Millwood homes within three years.

“If I did it all again I would do exactly the same,” says Colin Ives, who hopes to be in his new house this summer. “Only next time I would have an additional tank for collecting rainwater, so that we have enough to run our washing machine.”

Energy Efficiency Advice Centres (0800 512012; www.energysavingadvice.co.uk). Energy Saving Trust (0845 1207799; www.est.org.uk). National Energy Foundation (01908 665555; www.nef.org.uk). Millwood: www.millwood-designer-homes.co.uk, 01732 770991. Ecobuild Conference, Earls Court, February 27 to March 1 (020-7153 4565; www.ecobuild.co.uk)

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