Inside the Sydney house that sends a message to the top end of town

Jurgen Spangl and Karin Mundsperger wanted their new family home in one of Sydney’s most exclusive beachside suburbs to feel like living in nature, evoking the joys of camping and floating down a bush creek.

Their finished home, Holocene House, near Manly’s North Head National Park, is a tribute to the period before man-made climate change.

With a freshwater pool fed by a creek that cools the house, it won best new house at last month’s Australian Sustainability Awards after the jury described their visit there as an adventure.

Another Sydney home, a passive house called Sapling in Lilyfield by Anderson Architecture, was also highly commended, along with Hinderwell St House, a 135-metre square home by Perth’s MDC Architects.

Architect Clinton Cole (left) with owners of Holocene House, Karin Mundsperger and Jurgen Spangl, in the rear garden of the home.Credit: Nick Moir

Spangl, a former senior executive with a tech company, said he wanted to remind his peers that building a new house could be sustainable and beautiful. “We wanted to inspire people. When you look at building a high-end house, you see so many homes that use tonnes of concrete and pay very little attention to sustainability.”

Research by the Climate Council has found many homes in wealthy suburbs had large roofs and hardly any solar.

Spangl said: “The higher end of the market should lead because they can afford to experiment, they can push innovation and help make it cheaper for everyone. And that’s not happening enough.”

Compared to most bespoke homes, Holocene by CplusC Architects and Builders’ Clinton Cole is 10 per cent smaller than the average new home and about half to a third of the size of many new homes entered in architecture awards.

The property won last month’s Australian Sustainability Award for best new house.Credit: Michael Lassman

Spangl said his goal was to offset the embodied carbon used in the build as quickly as possible. “Currently, we anticipate it will take over 25 to 30 years, which is way faster than we originally estimated.”

Unlike the vast majority of homes, which will never be offset, the family was on track to generate more energy than was used in every aspect of its construction including materials, waste and operation.

Architect Cole said Holocene House was investigating what happens when we turn away from excess and toward nature.

“What does human-centred architecture look like now on a fragile planet? Holocene House sets an intention: let’s focus on sustaining life and giving our children a future,” he said.

Unlike many new high-end homes, Holocene doesn’t have many of the usual trappings. “There isn’t a shoe room,” said Cole, or six-car garage. There is only one car – an electric vehicle.

The design was developed after Cole asked the family of four what they wanted to feel like in their new home.

Floating down Eli Creek on K’gari (Fraser Island), Mundsperger was inspired. “The bush had formed a canopy. And we wrote a letter to Clinton saying this is how we want it to feel swimming in our natural pool.”

Coloured panes of glass were reflected in the pool and an awning covered in plants created a natural and changing piece of art, said Mundsperger.

Getting the colour and play of light right took experimentation. The family rearranged coloured bottles to see what looked best. They also built a model of the home in Lego and did other experiments to test its usability.

Trial and error led to the right balance of colour and light.Credit: Renata Dominik

Like Sapling in Lilyfield, the home used insulation – twice the performance of most houses – and well-sealed doors and windows.

The couple, accustomed to cosy homes equipped for snowy winters in their home country Austria, said they had never been as cold as living in Australia. But at Holocene, Spangl said they used the thermal underfloor heating only twice, making Cole wonder if the home needed it.

Sapling was highly commended in the Sustainability Awards for architecture and design. Credit: Tom Ferguson

Holocene is described as Australia’s first active house – generating more energy than was used in its creation and operation – while Anderson Architecture’s Sapling is a passive house, which minimises energy consumption.

The Australian Passive House Association says these homes result in energy savings of around 90 per cent because they have highly insulated and sealed walls as well as floors and windows that keep the temperature steady year-round.

Sapling’s project architect Alexandra Woods said one of the big pluses of a passive house was that its running costs were predictable.

“On a day like today, when the temperature is expected to reach 36, you might close the windows and rely on the house to keep the home cool,” she said last Wednesday.

Architect and sustainable design expert Tone Wheeler says building individual sustainable homes was noble, but not enough.

In the past, a house would be oriented to the north to manage hot and cold. But with block sizes getting smaller, the climate getting hotter and the culture changing, these designs could help. They would be more effective if they were included in higher-density developments planned by NSW near railway stations. Passive design’s mechanical filtration system would keep out car exhaust, pollen or smoke from bushfire.

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