Perfect extensions: two Londoners have built an entirely new house inside their Wandsworth cottage - doubling its value in the process

Ann had been living in a two-bedroom, two-storey terrace cottage in Wandsworth for 15 years before she submitted plans to extend it.

She wanted to go across the side return and also upwards to make a room in the loft. She didn’t use an architect but relied on her builder, and when it was finished the roof leaked, the wind came in and she was so unhappy about it she decided to sell the house.

At that crucial moment she met Christopher, now her husband, who had a house in Hammersmith and was about to move to take up a job in New York.

Chris was sales director of a furniture company. On impulse, the pair decided to park Chris’s modernist furniture in Ann’s house so that she could go with him to the US, where she subsequently trained as a child psychologist.

MOVE OR IMPROVE?

When the couple returned in 2009, the big decision lay ahead: whether to sell both their homes and start again, or live in one of the properties while selling the other. Ann’s house is close to Wandsworth Common in a really great area. The 1870s cottage is sturdy, its lovely garden enjoys east-facing light, and it has a sense of history about it. There was once a dairy in the street, producing milk from cows that grazed on the common. Wandsworth has good transport and chic local shops nearby, too.

They put off deciding, but visited the Open House London architecture and design festival, and other architecture exhibitions, to focus their ideas. Chris wanted a modern, open home and loves concrete. And “he’s a hoarder”, says Ann — he has 1,000 CDs — so bespoke storage would be important. She says she began to like modern styles more, even concrete.

Chris loves cooking and had just been allocated an allotment in Wandsworth which was tempting him to stay, so Ann suggested they had a new kitchen and stay put. But if they were going to sort out the kitchen, why not do the whole house? After her previous disaster, however, Ann was wary.

Chris’s sister had just had an extension done that the couple liked, so they invited her architect who came up with three possibilities. The third, which was the best and the biggest transformation, included hi-tech wood cladding on the back which the planners insisted on examining.

A BIGGER EXTENSION — AND LET’S HAVE A WINE CELLAR

The architect proposed opening up the ground floor and making it all run level; sweeping away the hall, and replacing the old staircase with a striking new one in beautifully detailed birch ply with gaps between the treads, and placing a window at the top to send light all the way down.

They removed the old rear extension and introduced a bigger one with exposed larch beams, some with glass between, a polished concrete floor, and a generous kitchen island with views of the garden through big sliding doors.

Bespoke birch storage under the new stairs incorporated a wine cellar and roomy cupboards. Between the old and new parts of the house sits a stylish concrete-lined bathroom with walk-in shower.

The all-new part can divide from the old with a sliding pocket door painted deep blue. “We’re future-proofed, too,” Ann says, “we could live on this floor if we want.”

On the floor above, instead of two bedrooms there’s now a master bedroom with walk-through dressing room; a bathroom, and a study that commands views of the back garden from a stylish wraparound window. Arnie the cat likes snoozing there.

The attic now has a good bedroom with an en suite shower room featuring a side wall of sandblasted glass that gets borrowed light from the skylight and staircase window.

Finally, the back was clad in the specially treated hardwood, which will weather silvery.

The architect’s ideas were so comprehensive that the builder said they’d built a whole new house inside the old one.

For Ann and Chris it wasn’t about creating more space but transforming the space they had to make it fit for modern life, so that it felt good with thoughtful detail and finish, and getting the kitchen-living area spot on. They both relish the silky concrete floor, and the deep, exposed pale golden timber roof joists that soften sound.

When she first saw it finished, Ann felt it was like a different house — and she hadn’t even had to move.

GET THE LOOK