Although Frans Venter always intended to build his house himself, he and his wife, Ronel, commissioned architect Karin Harcus-Harrison to design their new home when they managed to snag a rare, open piece of land on Northcliff Ridge. They already liked Karin’s approach, which focuses on space-making rather than any particular style, so they set out their requirements and gave her free rein to see what she would come up with.
Frans jokes that he didn't actually know what their new home would look like until he’d finished building it. 'It was a total surprise to me,' he says. 'Once it was complete, I stepped back, looked at it and thought how nice it was.'
What he saw was a steel, glass and concrete tower anchored to a nine-metre-high brick wall. Frans and Ronel had told Karin that they were eager to make the most of the site and its context on the steep, rocky ridge. 'The only way to create a view over the tree tops was to build high,' says Frans.
A skylight that runs the length of Frans and Ronel Venter’s Joburg house, above the staircase, not only lets in light – even the moonlight at night – but connects the concrete mass inside and the brick wall lightly, creating the impression that parts of it float. ‘We decided to emphasise the horizontal lines of the brickwork,’ says architect Karin Harcus-Harrison.
The site had been a tennis court before the subdivision that freed the land, which gave them a nice, solid foundation to build on, but restricted their footprint. Because they were on a slope, however, they could build high and still be barely visible from the road or impose on their neighbours. The rooftop patio has the views over the canopy of trees that Frans and Ronel had hoped for, out towards the vast open spaces beyond. 'Here, we're in the urban forest,' says Frans.
'Because the view is to the north, the context lent itself to the ideal position,' says Karin. The orientation is perfect for letting in natural light and promoting passive heating. In winter, when the sun is low, the ecofriendly pre-stressed concrete slabs that Frans used soak up the warmth during the day to keep the house, especially the upstairs rooms, warm at night. In summer, cross-ventilation keeps it cool. And the north orientation is perfect for their solar geyser.
At ground level, the gigantic camphor tree in the courtyard directed the design. 'The design is all about the spaces and how the house grows from the inside to the outside,' says Karin. 'Outside, you have the volume under the tree. The interior echoes that space.' Floor-to-ceiling glass doors slide open to connect the interior and exterior volumes.
The staircase along the anchoring wall coordinates the interior spaces. Above it, a skylight runs the length of the house, letting light flood in. 'I have this philosophy that when you join two shapes, you should join them lightly, which usually means using glass,' says Karin. 'You have the mass of the wall and the concrete slabs, but by separating the two you can create the illusion of floating space.'
In keeping with the integrity of the exposed steel and concrete of the structure, other industrial elements have crept into the finishes. Metal conduits run along the ceilings to the lights, and piping from the extractor fan in the kitchen has also become a decorative element.
Frans and two-year-old Heidi in the open-plan kitchen and living area. Frans designed and built the kitchen and the dining-room table.
Much of the furniture was designed and custom-made by Frans: in addition to the kitchen and all the built-in cupboards
and cabinets, he also made the dining table, main bed, and daughter Heidi's cot. The fortuitously appropriate 1960s wooden lounge suite was inherited from Frans’ parents, adding subtle vintage flare, while pops of colour save the interiors from becoming stark or cold.
The drama of this home, however, is in the architecture and its dialogue with its surroundings; in the contrast between the light and heavy elements; in the light that floods in, even from the moon at night; and in the sheer audacity of having a modern tower nestled unobtrusively among the tree tops. If ever there was an argument for giving an architect an open brief, this is it.
Karin Harcus-Harrison, originandjames.co.za
Originally published in HL Jan/Feb 2015