Designed 1968 in by icon of Australian organic architecture David Hollander,

the house sits like massive boulders on a hillside, with its sweeping cement curves nestled under a canopy of gumtrees. Walk through the asymmetrical front door and you enter a cosy burrow-like interior, with winding walls, shafts of daylight coming through the skylights, and planter boxes filling the spaces with greenery. “It was nonconformist and experimental, and reflective of its time,” says passionate owner Nancy Renzi of Renzi Design, who signed on the bottom line three days after the home went on the market. “The house was absolutely stunning – I loved the way it sits in the landscape, how it feels so good inside because of the rounded walls, and the light coming through those funny windows in the ceilings. It was like a fantasy land.”

While it originally embodied the anticipation and excitement that typified the ’60s, a renovation by the former owners had unfortunately left it with echoes of the ’80s, says Nancy, and chunky timber joinery that was at odds with the floating free forms. And the security screens on the windows were jarring. “The owners had tried to make the house look normal, by introducing lots of squares and rectangles, but that is something you can never do,” she says. “They replaced the original copper fittings with shiny chrome, and introduced a palette of greys, which made it look cold and uninviting. I wanted to strip it all back and play off the form and texture – shapes are the star of the show.”

Nancy found a rich source of inspiration for the transformation. The house had won House of the Year for a national magazine in 1972 and, chronicled in that title’s yellowing pages, was the home with its original decor. Hollander’s concept and Nancy’s were in tune, which validated the stripping of the interior she was about to undertake. First up, all the walls had to be resprayed with textured coating, then painted white. “Colour on the walls would close you in,” Nancy says. She reintroduced copper in the fittings – such as the pendant lights, door handles and kitchen drawer pulls – and installed warming solid timber doors throughout the home.

She also exposed the original aggregate floors that echoed the textured concrete walls, and restored the planter boxes that the former owners had covered. The real talking piece – the “conversation pit” in the living room – was richly upholstered to restore it to its original function. Nancy opted for “organic shapes and textures, with no sharp edges”. Colourful bottles combine with a flokati rug and Mongolian wool and velvet cushions. Throughout the home, she has mixed design classics – such as Eero Saarinen’s Tulip dining table, Arne Jacobsen’s Egg chairs, and Achille and

Pier Giacomo Castiglioni’s Arco lamp – with contemporary chic. “I didn’t want retro-shop kitsch, so I mixed original 1970s pieces with cutting-edge, quirky Italian designs.”

While the rooms are bathed in natural light during the day, after sundown the mood switches, thanks to cove lighting ingeniously placed within nooks in the ceiling, which also accents the wonderful architectural twists and turns that are so integral to the home. “The lighting is amazing,” Nancy says. “All the curves light up, and it’s so moody. It screams, ‘Let’s have a party.’”

Plants are used both internally and externally to emphasise the organic nature of the house, with creepers in the planter boxes and sculptural monstera deliciosa

(a firm 1960s favourite) throughout. Externally, she has grown ivy to cover the walls, both to insulate the house and to make it meld even more with the landscape. no doubt

There’s thatthat David Hollander would approve.

“I LOVED THE WAY ITS ITS IN THE LANDSCAPE, HOW IT FEELS SO GOOD INSIDE BECAUSE OF THE ROUNDED WALLS AND THE LIGHT COMING THROUGH THOSE FUNNY WINDOWS IN THE CEILINGS.”

– Owner Nancy Renzi

“I DIDN’T WANT RETRO-SHOP KITSCH, SO I MIXED ORIGINAL 1970s PIECES WITH CUTTING-EDGE, QUIRKY ITALIAN DESIGNS.”

THIS PAGE The multilevel house makes the most of its sloping site. The artwork left of the dining table is by New Zealand artist Irene Ferguson. The original 1970s copper Lucite swivel chairs were sourced online. OPPOSITE Miles, one of Nancy’s twin sons, relaxes in the “conversation pit”, the central point of the home. The 1971 Curtis Jeré wall installation is a perfect solution for the curved wall in this room. Purple Egg chairs by Arne Jacobsen for Fritz Hansen and a Panthella table lamp by Verner Panton and Louis Poulsen add to the retro vibe.

THIS PAGE Nooks can be found everywhere, adding to the home’s cosiness. In this one, a collection of artworks hangs above a Love Affair sofa by Erba Italia. OPPOSITE The Holly All pot/chair/ sculpture by Philippe Starck for Serralunga could have been tailormade for the dining area. Indoor plants throughout the house emphasise the organic nature of the building. The artwork is by Dutch artist Wim Worm.

The unusual house embraces its natural bush environment in Sydney’s Northern Beaches region, so Nancy installed hardwood decking to make the most of the outside spaces. Clover chairs by Ron Arad for Driade bring a quirky vibe, as do the LED light-up plant pots.

THIS PAGE Philippe Starck’s Bubble Club furniture for Kartell creates a funky living hub among the greenery. The copper theme continues with the coffee table and fireplace. OPPOSITE, CLOCKWISE FROM TOP LEFT The fabulous Numero modular lounge suite by Featherston was re-upholstered in Kvadrat wool, and is complemented by Reverso’s DNA bookcase and Emanuele Zenere’s Yo-Yo coffee table (both for Cattelan Italia); Nancy’s dog Luna often keeps her company in the home office; bright Missoni bedding and a funky Kartell lamp create contrast with the white walls in Nancy’s son Charley’s room; the dual-basin vanity and rounded edges on the mirror echo the home’s curves.