How Zac Efron is transforming an Aussie bush block with an unlikely material

When Zac Efron lies down to sleep in his new home on an Australian bush block, it will be on a mattress made from hemp.

In fact, the sustainable material will be used throughout the residence: as building blocks, insulation, curtains and even joinery.

The Iron Claw actor engaged creator and environmental activist Joost Bakker to design a sustainable six-bedroom, six-bathroom home on Efron’s almost 130-hectare property in the NSW Tweed Valley between Byron Bay and the Gold Coast.

Major construction on the Hollywood star’s off-grid northern rivers home is slated to begin in the new year.

“I really believe in this idea that our architecture can actually be beneficial to the environment,” Bakker said, adding that Efron’s brief was that he wanted the “most healthy home on the planet,” with sustainable materials that “sit lightly on the earth.”

The star of High School Musical bought the property in 2020, and the listing shows it traded for $2 million. Public records show the block was settled in the name of Zachary Efron, with the private retreat offering rainforest, creeks, waterfalls and bushwalking trails.

Joost has worked with architects, designers and other experts for the project he dubbed “Zac’s greenhouse”. It will feature 100 tonnes of soil on a flat roof that acts as a foundation for the house.

Hemp, he said, will be incorporated throughout the home.

“The mattresses that Zac will sleep on, they’ll be completely plant-based, natural hemp-based mattresses,” Joost said.

Insulation, curtains, rugs and internal walls will be made of hemp, he said, as will the joinery in the kitchens. This is a technique that featured in an award-winning design for Woodleigh School on Melbourne’s Mornington Peninsula, co-developed by Bakker.

For Efron’s build, there is potential for the washing machine and dryer to be made partly from hemp, and battery technologies that use hemp are being considered.

“So we’re really using it in so many different ways throughout the building,” Joost said.

Industrial hemp is a form of cannabis which has very low tetrahydrocannabinol (THC), the component in cannabis that makes users feel high. Laws associated with hemp in Australia changed in 2017, meaning humans could consume hemp food products and industrial hemp could be grown for seed supply and for fibre.

Professor Rachel Burton, who specialises in plant science at University of Adelaide, said the hemp industry was growing. Despite hemp not being widely used yet, she said there was potential for whole houses to be built out of the “long-lasting” product in future.

“Hemp is a crop that essentially grows quite fast, but it fixes carbon as it grows. So the material that you end up with is carbon-neutral,” Burton said. “It’s sustainable … in terms of the Australian landscape, it’s fireproof.”

In construction, hemp can be used for flooring, but is mainly used to build walls, said Burton. A part of the hemp called the “hurd” is mixed with a binder, generally lime, to create a mud-like blend that is then put between boards.

“You just pack it in, and then you just let it dry, and then take the boards off, and essentially, you have a wall,” she said.

For Efron’s house, Joost has worked with a Victorian block maker to create hemp bricks which don’t need lime, a product he said was often mined.

Instead, they are using oyster shells to bind the hemp to create bricks that look like Besser blocks. They are pricier than conventional brick, but may speed up construction as they are lighter.

“You get a really beautiful block,” he said. “They’re great because they pull in pollution from the atmosphere.”

Joost estimated they would need around 2200 hemp-based blocks for Efron’s home.

Burton said the lack of processing facilities was slowing the use of hemp in construction. Other experts say builders need more training and education.

“There’s quite a lot of work to advertise the benefits of hemp … and as builders get more familiar with it, I think it will be incorporated,” she said.

“I’m hopeful that it will because … we have to start looking at different building materials.”

Sara Wilkinson, professor of sustainable property at the University of Technology Sydney, said as hemp was a low-carbon material, it was more sustainable than conventional materials like brick.

“Given the large environmental impact of our conventional building materials – these low carbon sustainable materials are much needed,” she said.

As for Efron’s hemp-forward home, council has approved plans and foundation work has been done, Joost said, with the “actual build” to begin in February next year. Joost intends September completion.

All internal walls are designed to “pull in pollution and breathe,” Joost said, adding that even the floor was designed so it was grounded.

“When Zac walks barefoot throughout his building, he’s always connected to the earth’s magnetic field.”