One of the first things you notice as you enter Kate Haxell’s home is the bendy staircase. The craft book writer and editor has knocked out half her stairs and rebuilt them with a 90-degree corner, leading down into the open-plan living area instead of towards the front door.

I’ve used cooler colours on the walls, but it doesn’t feel cold. I’d never, ever have a white room

“Usually, you walk into a house and the first thing you see is something telling you to go somewhere else, so we changed the shape of the staircase,” says Haxell. It is just one of many personal tweaks and bespoke items in the house – often the handiwork of her husband Philip, a set builder and model maker.

When they bought the Victorian terraced house in Camberwell, south London 15 years ago, five male medical students had been living there. “It was insanitary,” she says. “Your feet stuck to the bedroom carpet.” The couple “camped out” upstairs while they knocked through walls below, choosing a different shade for each room as they went along.

“They’re cooler colours, but it doesn’t feel cold,” says Haxell. “I would never, ever have a white room. Unless you have amazing architectural beauty, it reminds me of a cheap hotel.”

Facebook Twitter Pinterest Mix and match: the kitchen with its copper oven surround. Photograph: Holly Jolliffe/The Observer

Haxell has fond memories of her 70s childhood, especially of when her grandparents moved into a house in Surrey that had been decorated in line with the latest fashions. “It was completely fabulous. They had a lilac bathroom suite, which I thought was just so cool. There was a bar in the kitchen area and sparkly stars on the ceiling,” she says.

Philip’s ‘play room’ in the loft is decorated in bold orange with neon lights from jobs and shoots he has done

Now there are 70s influences scattered throughout her own house, including a mirror bar, originally created by Philip as a prop for a Hermès shop window, and a zebra-print Ikea pouffe in the dining-room area.

Haxell says they originally wanted a shagpile carpet fitted in the bedroom, but it was too expensive. Now furry rugs surround the curved, grey velvet-covered base of their bed instead. Haxell made the retro-style white headboard herself and they chose a whimsical painted cloudscape for the ceiling.

“I wouldn’t want the decoration to be too serious. I like funny things,” she says, whose birthday present this year was the golden plant-shaped lamp in the sitting room, also made by Philip. “It is loud. We have some quirky bits of furniture and the wall colours sort of offset them. If the walls were red, it would be very Andrew Logan.”

Facebook Twitter Pinterest Shelf life: the dining area. Photograph: Holly Jolliffe/The Observer

Instead of a fitted kitchen, theirs is a mix of appliances, second-hand objects and custom-made storage units. The tall, metallic oven casing with a built-in crockery cupboard was made with a sheet of copper that Philip found going spare.

“It makes me think of Victorian kitchens, with all those copper pans hanging up,” says Haxell. The sink, originally from a laboratory, was picked up in a salvage yard, while the utilitarian-looking trolley next to the fridge was bought years ago at Spitalfields market.

The couple have two cats called Vincent and Dustin. They have made the most of the extra space and each has a room to themselves as well as their shared bedroom – Kate’s office, where she keeps some of her five sewing machines, is painted green, while Philip’s “playroom” in the loft is decorated in bold orange with neon lights from jobs and shoots he has done.

The house, which Haxell says is not yet finished, has been a slow-burning project: it took six months for Philip to finish stencilling the trees embossed on the landing walls. “We’ve taken a long time to do it, working in batches and considering different elements,” she says. “If it doesn’t work, we’ll have another go. If your sanity can stand that, you end up with a house that’s incredibly personal.”