"With LED lights, double glazing and broadband, treehouses have moved into the 21st century", says Simon Busch.
"Nobody needs one." This is a peculiar thing for a treehouse builder to say about treehouses. But that is exactly what Paul Cameron tells me as he and his team at Treehouse Life puts the finishing touches on their latest project, a multi-decked construction spiralling around a thick old blue cedar in the sweeping grounds of a property in Surrey, south-east England. "They are pure whim, " he adds, an "emotional space".
You cannot, Cameron says, "just stick a house in a tree and expect kids to have fun". Treehouses have transcended the elevated-shed stage and his clients now want to explore their full scope as outside spaces for adults and children.
Take the design for the Surrey property, which spills beyond the multiple twisting platforms - what he calls his signature style - of the treehouse itself to a "secret entrance" (assuming a child's somewhat myopic conception of secrecy) starting in a vaulting natural hollow in a hedge and continuing , via a stone-clad climbing tower, along a rope bridge. There is also a vaguely African-looking thatched roof and more traditional childish accroutements such as a slide. But he has also incorporated a garden location to make the most of the evening light, decks that will comfortably accommodate drinks after work and pinpoint LEDs to keep things softly in sight once the sun has set and the children have been sent to bed.
Treehouse options have proliferated to such an extent that companies such as Cameron's now present clients with computer-drawn, three-dimensional models of potential designs, wrapped around their chosen trees, long before a saw is taken to wood. Increasingly the brief is to include all the trappings of conventional houses.