Grand Designs, series 16, episode 1: Kevin McCloud falls for 'miraculous' 40ft-high tree house built on an abandoned garden site in Gloucestershire

After 16 seasons of Grand Designs you might think Kevin McCloud had seen it all. But the “big, proper, grown-up treehouse” featured in the first episode of the new series got the presenter so excited he practically fell out of it.

The large larch-clad home 40ft up in the trees took more than two years to build on an overgrown, neglected half acre of land in the heart of a Gloucestershire town – a site that plumber Jon Martin spotted as a child growing up in Dursley and which four decades later he acquired for £85,000.

Jon and his partner, ceramicist Noreen Jaafar, self-built the wooden parts of the three-tiered property to save money after delays pushed their £268,000 build budget to the limit.

The presence of protected trees on the plot meant planners forbade them from building concrete foundations which might damage the tangle of roots. The solution? Build upwards and on stilts, pinning the property into the ground with 16 narrow metal piles, upon which 10 tonnes of steel and a wooden house effectively floats.

The resulting building is almost completely hidden from its surroundings by foliage meaning that from inside you’d never know it was part of a bustling town, quite literally sandwiched between a supermarket car park and a Methodist church.

Accessible via a 12ft-high narrow walkway, the “anti-gravity” house is made up of three boxes, a small hidden ground-floor which serves as Noreen’s studio, a large middle-layer which contains an open-plan living area surrounded by huge verandas. On top is smaller box with a flat roof housing the master suite and three guest bedrooms.

Noreen’s stunning ceramics grace the kitchen and bathroom, Jon’s paintings hang on the walls and the finishes are a testament to the joys of careful salvaging. The bottom two floors are laid with blue slate reclaimed from an old Rolls Royce garage; while upstairs the floorboards are from an old basketball court, complete with painted markings which give an almost Modernist graphic effect.

There are no contiguous external walls, the house has its own natural water supply and it is insulated with a nifty kind of expanding foam usually used on properties in Canada.

By the time filming stopped a couple of weeks ago the house was almost finished and Noreen and Jon surpassed their budget by around £2,000 – and they expect to spend a further £12,000 finishing the bedrooms and ground floor.

McCloud described their squirrel-level living arrangements as “flipping brilliant”, “a miracle” and “truly magical”. He seemed ready to move in if they'd let him.

“The very idea of the escape, the fantasy of living a dreamlike existence…the thing is, as you grow up, you leave these things aside,” McCloud said. “But given the chance of building a permanent treehouse as your home – you would, wouldn’t you?”

Grand Designs is on at 9pm on Wednesdays on Channel 4