Dress circle

I knew it wouldn't be an easy house to build, but I wanted to try something different, something sexy," says architect Douglas Murray in the half-moon office of his spectacular, circular wooden house in Strathpeffer, near Inverness. Easy it wasn't; weatherproofing - vital in the Highlands - took four months instead of the usual couple of weeks, and financial compromises had to be made en route, including the abandonment of a planned moat.

I knew it wouldn't be an easy house to build, but I wanted to try something different, something sexy," says architect Douglas Murray in the half-moon office of his spectacular, circular wooden house in Strathpeffer, near Inverness. Easy it wasn't; weatherproofing - vital in the Highlands - took four months instead of the usual couple of weeks, and financial compromises had to be made en route, including the abandonment of a planned moat.

But the fact that the house is round wasn't the only challenge Murray set himself. He also wanted to build a house entirely on ecological principles - solar panels; local, sustainable materials; no toxic chemicals; the lot.

And, apart from a few minor concessions, he has succeeded. The house is not only visually exciting, it is also a "healthy house", fulfilling the twin goals of being ecologically sound and built to nurture human life rather than provoke asthma attacks or allergies.

"I have always been interested in environmental issues, but for the last six or seven years I have focused more on ecological buildings," says Murray, who is a member of the Scottish Ecological Design Association. "I think it's the only way forward. People are becoming much more interested in medical statistics such as the rise in asthma and allergies, and the possible links with home environments."

The house is actually two circular buildings, linked by a porch. The three-storey main house has a wraparound conservatory facing south and west, while the single-storey structure houses Murray's office and the service area. Both buildings are built from vertical panels of native Douglas fir on top of a plinth of local stone. The wood, which contains natural oils making it resistant to rot, has been left untreated to allow the sun to bleach it, and woodworm prevention was abandoned because it contained toxic chemicals.

Both structures are crowned by conical roofs of reused slate, and a spectacular skylight at the apex of the main building floods the central stairwell with light. It's a spacious home, and there are enough bedrooms (five) for visits from the four grown-up children from Murray and his wife Anita's previous marriages. The ground floor contains a kitchen, a sitting room, a bathroom and a music room, where Anita teaches piano and which doubles as a spare bedroom. Three bedrooms and another bathroom fill the first floor, and the third storey, still unfinished, will become the master bedroom, with open-plan sitting room and small library.

All the rooms are wedge-shaped, which Murray admits can be restrictive but is more fun than box shapes. The central stairwell takes care of the pointed ends, and though furniture placed along the curved outside wall will have a gap behind it, the two inside walls are straight.

Murray has found that clients are increasingly willing to consider the ecological aspects of new-builds. "Of course the reasons people compromise on their environmental principles are invariably financial," he says, "but you really can build a 'healthy' house without spending a huge amount more." The house took longer to build and cost more than one of standard construction, but Murray says this has more to do with it being circular. "There were technical problems, so it was more expensive," he says. "For instance, we couldn't fabricate the wood panels by the standard method."

One of the successes of the house is the efficiency of the insulation, which maximises the underfloor heating system. Murray chose Warmcel cellulose insulation, which uses chopped-up newspaper that is blown into the wall cavities under pressure. "When we switch the heating off, the house stays warm for several days," he says. "The downside is that the temperature can't be adjusted quickly, but we can always open a couple of windows."

The solar panels are certainly effective for creating plenty of hot water - unless, says Murray, there has been no sun for several days. Then the boiler comes into its own, fuelled by wood chips, a waste product of forestry.

Murray has been liberal with his use of glass - there are 72 double- or triple-glazed windows, so no shortage of stunning views across the Highlands. Isn't that a lot of glass to clean? He says that they simply don't clean the windows. "There's been no need in the 18 months since we moved in. We don't get much pollution up here and the rain is clean." There are other advantages, too. "We've had some terrific gales," says Murray. "But the wind just slips round the building. There are no flat walls or gables for it to buffet."

The round house has been much admired locally. If the couple wanted to sell it, would they recoup their investment? "I'll have no problem selling this house," says Murray. "It cost around £200,000 to build, including the cost of the land, and I could sell it now for £300,000." A house of similar size in the area would normally be nearer £200,000, but the uniqueness and ecology features will attract buyers. As Murray says, "People are much more aware of health and ecological issues now, and they want their homes to reflect that."

For those who can only aspire to an ecological round house but want to make their homes greener, Murray has some advice. "The first thing is to make your house completely draught-proof to conserve energy. If you have wooden floors, seal the joins between the floor and the wall behind the skirting boards - a classic place to let in draughts. The second thing is to look at getting solar panels, for which some funding is available via the Energy Savings Trust."

If you want to make ecological improvements to your home, or rebuild a derelict property, the Ecology Building Society may provide loans where other lenders have refused funds. Find out more at www.ecology.co.uk