IN PICTURES | Black walls give this arty Joburg home a muted glamour

The design of Christian van der Walt and Anli Jones's Johannesburg home began with a door. The pair came across a tall, narrow, wrought-iron chateau door in an antique shop near where they lived. The door was rusted, had lost its glass and had no handles, but it awakened a vision.

"We thought, this is great," says Anli. "How do we make it work?"

The house as it stands now is largely a response to that question. It was essentially a granny cottage, an outbuilding on a plot with a larger house, which has since been converted into a street-facing interior design studio. The stand was subdivided and as a result, the cottage was hidden at the end of a panhandle along a narrow driveway.

When the couple first moved in, it had yellow painted bricks, knotty pine ceilings and avocado bathrooms.

Christian, who works with special effects and animation in film and advertising, and Anli, who has a background in fashion design, designed the house themselves. With the door in mind, they sketched ideas on napkins over many dinners, and eventually a plan started to emerge.

"At my last office, my neighbour was an architectural firm," says Christian. He helped create cinematic "visualisations" for some of their projects, so had experience creating three-dimensional renditions of rooms from architectural sketches, and worked up the plans.

Over three years, he and Anli went about transforming the cottage into a kind of modern tower in an enchanted garden.

"We did it in stages, so we used the layout of the old building and just enlarged and extended," says Christian. As they built in one area, they lived in another, until they'd come full circle. "Exactly as you shouldn't," he adds.

Originally the ceilings were meant to be the height of the antique door, which they had beautifully restored. But one evening, Christian and Anli arrived home to find the builder had mistakenly added an extra metre to the wall. "He asked if we could leave it," says Anli.

Together they conceded that it would be more work to undo what had been done, and so they went with it.

The exaggerated volume, particularly in the central living room and the adjacent study-cum-guest room - for which the ironmonger who restored the original antique door created a matching replica - is at the heart of the character of the house. The height, combined with the black walls and the monochrome furnishings of the interiors, creates an almost undefined sense of space

"Limitless" is how Anli describes it. Especially at night when you're almost unaware of the ceiling and the walls seem to recede, enveloping the interiors in a dark, velvety atmosphere of mysterious luxury.

Contrary to the standard idea of a white cube, the dark walls are a trick Christian noticed in a number of art galleries. "I look a photo in the Louvre, and it was the same setup," he says. The National Gallery in London has never had white walls, and he noticed it again at the Scottish National Portrait Gallery in Edinburgh. "The walls disappear, but they also make whatever you put in front of them pop," he says. "You're seeing the things in the space, not the space."

He calls the house a "showcase space", because the couple's collection of art and artefacts, books and furnishings come to life in the chiaroscuro of each room, as if in a cabinet of curiosities. There are contemporary local designs and vintage pieces; up-to-the-minute artworks, and restored portraits in oils picked up on auction.

The atmosphere takes on an almost fantastical dimension; a glamorous glimmer that seems to resolve the combination of antique and contemporary design. The two sofas in the centre of the living room sum up the basis of the interiors: an old black leather Chesterfield and, opposite, a modern cream Italian one. Almost everything, if it doesn't have a metallic glint, is either black or white ... and mostly black. The atmospheric lighting imparts sparkle and romance.

"It's like a romantic hole in the wall," says Christian. "When you have the candles and the fire going, it's magical."

The dark exterior walls also work to emphasise the greenery of the garden rather than drawing attention to themselves.

Christian and Anli have planted a beautifully lush formal vegetable garden. "It never seems to know when it's autumn or winter," says Anli. "It's incredibly sheltered, so it stays green all year."

There are also box hedges and olive trees that create exterior rooms for al fresco dining and entertaining. The air is scented with lavender. There are even quails, which have had chicks. "They look like popcorn," says Anli.

This almost pastoral dimension of life down the panhandle is an exploration of urban green space that Anli and Christian find affirming. "The ability to live like you're in the country, but in the city, is something we aspire to," says Christian.

Despite their home's heady combination of whimsy and glamour, the satisfaction Christian and Anli find in something like cooking with herbs from their own garden while living in an urbanised area, is a surprisingly contemporary ideal.

Then again, Christian and Anli are firm believers in functional aesthetics. The copper pots and pans in the kitchen - and the crystal chandelier - are undeniably beautiful, but, says Christian, it's all part of taking pleasure in ordinary things.

"It's about the joy of ordinary objects," he says. "If you're going to cook three meals a day, then it might as well become something that you love doing. If you're going to live in a place, it should be uplifting."

The romance of this suburban castle is not so much an escape from everyday life as a haven of beauty and glamour - and more than a little fantasy - that paradoxically grounds Christian and Anli; it makes being at home a "worthwhile experience".