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He has designed homes for Noel Gallagher and gifted restaurateur Oliver Peyton; his wife Madeleine, 39, works for international art gallery Hauser & Wirth, and he’s done more trendsetting restaurant interiors than you could shake a breadstick at, including at Mash, Isola, Chotto Matte and now Marylebone’s new star, Fucina — yet architect Andy Martin, 52, calls his own north London home “the ugly house”.

WHAT IT COST House in 2012: £620,000 Total spend, excluding architect’s fees and using reclaimed items: £165,000 Value now: £1.65 million

It’s part joke and part truth from the surf-loving Australian. The outside is a standard Thirties terrace near Kensal Rise, not everyone’s favourite style, which Martin has kept. But the innards and back have been totally altered to make more light, a big open ground floor and an entire extra floor on top. He has also extended out 15 feet at the back.

At the end of the smallish garden he has tucked a smart swimming pool and a small grass-topped sauna and studio. Yet it all looks of a piece, from the big through-space downstairs on two levels, leading to floor-to ceiling glass doors, to the childrens’ bedrooms on the middle floor, to the master suite at the top.

Done on a budget: the skylit kitchen, designed around the steel island, is fitted with second-hand units. The double fridge and wine cooler are also second-hand, but top quality (Charles Hosea)

RECLAIMED MATERIALS

This top floor is a delight. In the now dormered roof space, instead of an empty attic there’s a resin-floored double bedroom with two walls of bespoke plywood cupboards and drawers, and an egg bath in front of the window. There is also an entirely glass-walled bathroom. Its steel-frames hold reeded glass, making something that’s both special and slightly opaque — and it filters light down the stairs, too.

While the children’s rooms are simple, with reclaimed wide wooden floorboards and bespoke ply doors with cheery yellow lever handles that are easy for little hands, the ground floor is also pretty special.

Since this busy couple love cooking and entertaining, and have three children — Eero, 12, Panama, 10 and Sonny Jim, who’s four — along with an eight-months-old, endlessly lively fox terrier called Thomas, the ground floor has to be childproof as well as stylish and relaxed.

It was all done on a budget, using reclaimed materials wherever possible. The striking blue-black floor bricks are reclaimed and the original floorboards now grace one spine wall painted black — a great visual background for the wood-burning stove, which belts out heat.

Split-level: the new ground floor open-plan living space (Charles Hosea)

The steel kitchen uses second-hand units. “I designed the kitchen round the steel island,” Martin says. He added a white marble top, and lined the side wall with steel units and wooden shelves. The double fridge and wine cooler are both second-hand, but top quality.

ECO STYLE

This laid-back, apparently effortless style is instantly welcoming and comfortable. The striking pendant light, a giant spaceship hovering over the dining table, was designed for Isola in Knightsbridge. Other pieces of furniture designed by Martin are dotted about, such as the Block-T table and wooden lamp. “This is the most eco-house I’ve done so far,” he says, pointing out that it’s very different from the high-end homes he’s known for.

He studied architecture in Australia, where a chance meeting in 1983 with architect Will Alsop, who went to lecture in Sydney and was billeted with Martin, brought him to finish his studies in London. Once qualified he lived in several countries, enjoying a long stint in Paris, where he collaborated with designer Marc Newson.

BLANK CANVAS

When he was designing Isola for Oliver Peyton he met Madeleine, who’s Norwegian, at a party. After living in several flats, including in Notting Hill, they were looking to buy a family home. “I was a Notting Hill snob,” Martin confesses. “I thought we’d have to go west.” They spotted the house in Kensal Rise — then unappealing, but rising fast — partly because of the Overground. “Madeleine convinced me not to go to Ealing.”

Martin explains why Thirties houses can be ideal blank canvases to transform into good family homes: “They have good, roomy proportions that are easier to work with, fewer chimney breasts, and good ceiling heights. This one was south facing. It was a no-brainer.” The original smaller ground floor was divided into three cramped rooms including a small kitchen; there were three bedrooms and a bathroom above.

The master suite: in the dormered roof space has a resin floor and walls of bespoke plywood drawers and cupboards (Charles Hosea)

That was it. Martin saw what he could do at once — and that the attic could be opened up under permitted development rights. Since several locals had extended the back, he knew he would also be able to do that, with planning consents.

The rest was plain sailing. A rapid six-month build started soon after purchase in 2012, and the family moved in on Christmas Eve. “Though the brick floor wasn’t laid,” he says matter-of-factly. Most of us would be phased by that. But since he’d added almost half as much volume to the home and massively improved it, a few missing bricks didn’t spoil Christmas.

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