Self-build eco-home in Ealing: solar panels, triple glazing and sedum roof mean bills are just £50 a month in stylish family house

For Nick and Caroline Baker, the building of their dream home had its complications.

Five trucks of concrete for the foundations disrupted the local school run; one pile had to be driven 54ft into the clay subsoil to create stability, blowing the budget; the timber frame was an assault course, and their daughter was born four days before the first spade broke ground.

But after a nine-month build, the house they share with Isla, now eight, and Caroline’s niece Thalia, 25, emerged. The glass and timber butterfly-shaped two-storey structure is set in a gorgeous garden down a romantic leafy track with two ancient protected oak trees.

As well as a big kitchen-diner, sitting room and study, there are four bedrooms and three bathrooms, enjoying views and sunlight all the way around. There are no corridors or poky corners, just space and light, brightness and quietness.

“It’s a garden with a house rather than a house with a garden,” Nick explains.

Wonderful extras include a bath set before a window with an entirely tree-filled view, and a whole wall of windows in the master bedroom suite lets the couple wake up and watch the sunrise.

Three lucky cats loll on the stone paving outside. Neither they nor their owners can quite believe this is Ealing.

From its Hollywood-style double-height hall, bedazzled at night by moonlight, to the striped Western cedar on the outside, attached with 10,000 steel nails in perfect rows by proud carpenters, this house has major eco-credentials: “All but the ground floor [which is 50 per cent triple-laminated glass] meets passive-house standards,” Nick says.

The thick walls are packed with a foot of Rockwool. “Insulate, insulate, insulate!” He cries with true eco-warrior vim.

A big sedum roof encourages wildlife, and there’s a phalanx of solar panels on the other section of roof. These heat water and create electricity, so the bills of this 3,500sq ft family house are only £50 a month.

Yet it happened by chance. Architect Nick, 51, had been working for Norman Foster on the Berlin Reichstag, and returned to London in 2005, where he met Caroline, who’s in marketing.

They married in 2007 and began house hunting in the Ealing area. “Houses were beyond our budget, about £2 million,” says Caroline, 50.

Then she spotted a building plot of two joined back gardens with planning permission for a house. In fact, Nick had seen it but discarded it because he found the house “awful”. Nor could they afford it. But this time they focused on the plot not the house, and gave it a second look.

They talked next to the owner, who agreed to drop the price. They took a risk and bought the land without any assurance from the planners that they could change the existing house design.

But they asked each other whether, if the worst happened, they could live in it, before buying at the end of 2009. The seller was moving out, so they rented his flat, right beside the plot.

Nick drew three designs for Caroline, one of which was circular. He also talked to all the neighbours and showed them her chosen design, which resulted in no objections.

One neighbour reasonably requested a screen of trees, which the couple happily added to the many other trees they bought for the garden.

Nick felt sure of being able to redesign their house, and that conviction paid off. He also managed to increase its size by 25 per cent.

Six months after work began, which is very fast, the house was watertight, and they focused on the interiors. “Isla and I spent a lot of time shopping for things for the house,” Caroline remembers. “Nick would have chosen one shade of white, and some grey,” she smiles. But she held firm for some colour.

Today, bold red kitchen worktops spice the overall gleaming white kitchen, while in each bathroom a differently coloured splashback of Venetian glass tiles offsets the grey floor and wall tiles, and two bedrooms have beautiful, bright feature wallpaper.

The effect of these nicely judged insertions against all the white and glass and pale oak floors is very elegant.

“But I blew the whole lighting budget on the modern chandelier in the hall,” Caroline confesses, with unrepentant satisfaction. She was right to. It is absolutely worth it.