Eco-dwelling: Room at the top

A far cry from the cramped, rickety constructions of our childhoods, modern treehouses are the ultimate in eco-dwelling. Oliver Bennett visits the new leafy suburbs

Traditionally, treehouses are wooden play-zones for children, but in line with the current fascination for different modes of living, the treehouse now also appeals to the downshifted, ecologically minded adult-at-play, in touch with his or her inner primate and possessed of the inexplicable human desire to leave the ground.

David and Betty Payne, for instance, have a treehouse in their Sussex garden that they use as a painting studio, a contemplative space and a school for their grandchildren. "It makes you feel part of nature," says David. "It gives you that marvellous feeling of climbing a tree, and the fact that the entrance is a rope bridge over a pond makes it extra special." Built from sustainable Scandinavian softwoods, it also creates an extra garden space that is not a conservatory.

The Payne's treehouse was built a year and a half ago, originally as an office, by the Paynes' son Andy, who, with his brother Simon, operates Blue Forest, one of a growing number of treehouse specialists. But while Blue Forest's treehouses are top-end - some have underfloor heating, double glazing, and even log-burning stoves - Andy believes that the current interest in treehouses is directly linked to the renewed interest in the environment, and in some of his more established treehouses he provides solar power, composting toilets and water-catchment systems. "There is so much you can do with two or three trees," says Andy, who takes on a lot of eco-travel work, and is launching a marque called Fair Stay, which aims to promote low-density, sustainable tourism.

Despite their sophistication, Blue Forest treehouses are not made as dwellings, although the Paynes have an eye on that possibility. Meanwhile, one architecture practice is planning treehouses as homes, and while they are far removed from the typical creaky wooden eyrie, they, too, are motivated by ecological values, in terms of both sustainability and immersion in nature.

Torquil McIntosh and Simon Mitchell, of the architectural firm Sybarite, have devised a "concept treehouse", which stands on stilts, and is prefabricated, modular, and customised to each site. The house is a far cry from the traditional treehouse: Sybarite's luxurious design features an optional roof terrace, whirlpool bath and shower. "It can go up to a five-bedroom house," says McIntosh, adding that it is built from glass-reinforced plastic, a material used in yachts, and will be made in boatyards. They are looking at potential manufacturers in Britain, France and Italy.

At the moment, the company is working on its first proper treehouse commission for the Joshua Tree National Park in California. They were to have built a treehouse in Hampshire, but the project fell through, which at least allowed them to check the structure's planning status. "The planners couldn't be specific with us until we had a real client and a real site," says McIntosh. Unsurprising, perhaps, as the home is designed for a rural site. "It works best in mature woodland," says McIntosh. "The idea is that the treetops are your garden."

This may cause green alarm bells to ring. But McIntosh emphasises that the Concept Tree House is designed according to sustainable principles, and that it makes for "minimal site impact", with a negligible "footprint". Built on three tripod legs, to avoid tree damage and allow wildlife to run free beneath it, the house's non-invasive design makes McIntosh muse that it could work in the green belt - although planners might disagree. "Also, the underside becomes another elevation."

There are other environmentally driven aspects to the house. Baffles on the underside provide ventilation, and are linked to batteries to generate electricity in the same way as a wind turbine: indeed, the house aims to be 70 per cent self-sufficient in power. Rainwater is caught for use in toilets and showers, and waste water is used, too, flowing off to ponds to be cleaned before returning to the water table. It uses recycled insulation and can carry solar panels - the California house in the desert will have them. But these eco-friendly palaces in the sky come at a price - about £1m, excluding the cost of the land.

On a different scale are Tom Chudleigh's Free Spirit Spheres, on Vancouver Island in Canada, which are more a meditation zone. "They're very restful," says Chudleigh. "As soon as I get into one, my troubles evaporate. It's all about oneness with nature."

A few years ago, Chudleigh built his first sphere, called Eve, suspended by ropes from trees and accessible by a stepladder (he later built a spiral staircase). Although not designed as a dwelling, there's enough room to stand up, electric light, a phone, and space for three to sleep. Indeed, Chudleigh himself lived in the sphere for a while. "All they lack is washroom facilities," he says. "The next sphere will have a composting outhouse."

Originally inspired by sailing boats, Chudleigh has made four spheres to date, steadily improving the design: the latest has a microwave and room for four. He has brought the cost down by switching to fibreglass. "You can paint it to look like wood,"he says.

Since they dangle from a height of at least 20 feet, the spheres need large, sturdy trees. "Finding the site and placing them is difficult," says Chudleigh. "You can use a helicopter, but it's expensive." Engineers are required to make them secure, but they do roll with the wind, which Chudleigh enjoys.

We may soon be able to see a Free Spirit Sphere on television as ITV is buying one for a forthcoming series of I'm a Celebrity, Get Me Out of Here!. In the meantime, Chudleigh's ambition is to build a sphere village. "There'd be a kitchen sphere, a bathroom sphere, and as much accommodation as you needed," he says.

So, while the treehouse might not be a viable dwelling, it is becoming a firm part of the travel industry, as the market for eco-lodges and leisure treehouses is booming. "We do treehouses for hotels, conference suites and entertainment facilities, as well as for children," says Gordon Brown of the Treehouse Company, the busiest British treehouse builder, responsible for constructing about 100 a year: it designed the enormous treehouse at the Alnwick Garden in Northumberland, which contains a 120-seat restaurant, two classrooms and two dining rooms (although some might discount it as a treehouse as it has concrete foundations).

However, despite massive demand, the company has yet to make a residential treehouse. "We get phone calls from people trying to get around planning for treehouses, hoping to classify it as a temporary structure," says Brown. "The trouble is, a treehouse needs to be up to building regulations, but it's difficult to quantify a tree, and therefore difficult to get insurance." Plumbing is the most difficult part, but, at present, the Treehouse Company is making a room for a hotel in Chester, with its own en-suite bathroom.

Finally, there is the treehouse as expression of place. The Eco Treehouse Company, based in the Peak District, is explicitly environmental and supported by a local New Environmental Economy grant scheme. The company's founder Craig Banks makes different tree structures, from children's hideaways to offices. "We're trying to stimulate environmental conservation in the Peak Parks," he says, "so we use local timber, sheep's-wool insulation, and plant-based finishes."

www.blueforest.com
www.sybarite-uk.com
www.freespiritspheres.com
www.treehouse-company.com
Eco Treehouse Company, via www.peakdistrictproducts.co.uk, or call 07929 616282