How we turned a 'square toad' into a princely new extension

With an impressive leap of imagination, a dreary carport became a designer extension now tipped for an award
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Not all architects are upfront enough to admit the importance of money to their clients — as if, say, 50 grand over budget is mere piffle. But to Phil Coffey, whose young practice already has a string of awards, and whose Court House in north London has been nominated for a RIBA award this year, money does matter.

So, when the owners of Court House, a young couple who were thinking of starting a family, came to him about converting their dreary carport into a useful room, he suggested doing a lot more — at much higher cost, but giving them much more in return.

In short, he suggested demolishing the carport altogether. Squatting at the rear of the property like a square toad, it was divided from the four-storey end-of-terrace Victorian brick house by the only “outside” space — a narrow, dank concrete well the same depth as the home’s existing basement.

Architects' Journel
© All photographs by Timothy Soar
A once gloomy basement in north London is now a fabulous suite of rooms plus a courtyard

No one used the depressingly dark well, so the owners suffered from the lack of a garden. Coffey suggested excavating the whole area below the carport right down to basement depth, then using the full footprint of the plot for rooms divided by a good-size courtyard, with a decked garden run right across the top. Once they’d taken it all in, the couple said yes.

About eight months after work started, the owners had a set of new basement rooms, including a bedroom with en suite that would be great for a teenager or guest, a big central courtyard, and a gorgeous, bright sitting room full of careful details: pale oak, a modern fire with steel breast, and white walls.

Despite being at basement level the room is bright because it not only has sliding glass windows on to the courtyard, but it also has a walk-over glass skylight made from triple-laminated glass. The courtyard itself, with glass walls and sliding doors on three sides, a polished concrete floor, and a simple concrete stair that looks as if it just clambered a hillside in Mykonos and arrived at a five-star hotel, provides terrific all-year views from the sitting room and the guest bedroom over on the other side.

Above the lot stretches the big, oak-decked garden, looking down into the courtyard through safe, high glass balustrading. The decked garden has whitewashed walls that add to the Greek feel, and has become a frequently used barbecue space.

Architects' Journel
The barbecue area, oak-decked and whitewashed, is a generous space (left); oak, glass and steel work together for a crisp finish (right)

Coffey’s bold plan added about 450sq ft of usable space (much more if one counts the decked area) and made a gorgeous Mediterranean internal garden that gets light most of the day — and is safe for a child to play in — plus a generous barbecue-and-entertaining space above. The whole lot cost almost £250,000 and is all very high spec. You wouldn’t get a studio flat for that in this part of town.

“I do think money is an important conversation,” Coffey said. “It would be wilful to throw people’s hard-earned money away. I want to end up with a happy client who loves their new home, and feels that what we’ve done is valuable in every sense. I don’t think there has ever been a project where we haven’t made money for our client. It costs about £4,000 a square metre to dig out and fit out a basement, but in central London it will be worth more afterwards.”

Attention has gone into the combination of polished concrete, white walls, pale American oak, glistening steel, and simply detailed glass. The whole effect is clean, light-reflecting and, like many artfully simple things, rather sumptuous. “One of the important things when we work on existing buildings like this is that we don’t want a jarring feeling from old to new,” said Coffey. “We want it to look as if it has always been there; a sense of seamless space. Confidence shows in design. If you make good decisions, space becomes more beautiful.”

Architects' Journel
The sitting room has good all-year views of the courtyard through the glass walls (left); above the new sitting room even more light pours in through a glass roof (right)

Photographs by Timothy Soar

Get the spec

* Architect:
* For polished concrete visit
* Paint: Dulux Trade pure brilliant white:
* Glazed sliding doors to courtyard and glazed pivot door at upper level:
* Bio-ethanol fireplace:
Architects' Journel
* Viabizzuno external wall lights:

* The AJ Small Projects awards are run annually by The Architects' Journal, with the aim of finding the best architecture built on a budget of £250,000 or less. For more information visit

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