Dutch-Australian designer and sustainability advocate Joost Bakker is designing an all-natural home in New South Wales for Hollywood actor Zac Efron. The project, he says, reflects a conviction he has held since adolescence: that the built environment must use only materials that can be “fully recycled or returned to the earth.”
Bakker met the Hollywood star in 2021, after Efron had sold his Los Angeles mansion and purchased land in Byron Bay NSW. Construction will begin this summer on the $2.65 million home.
Hemp Walls and Durra Panel at the Core
Internal walls will be made from hemp blocks, left exposed at Efron’s request after he visited Bakker’s own family home and responded to the look of the masonry. Efron specifically requested that the project use “as much hemp as possible,” Bakker said. The blocks are made with an oyster-shell binder being developed as an alternative to mined lime, in collaboration with the Shuck Don’t Chuck program.
A key structural and acoustic material throughout Bakker’s recent projects is Durra Panel, the straw-based compressed panel made in Bendigo from agricultural waste. Bakker has been a consistent advocate. “When I first started using Durra Panel, it just blew my mind that this company’s been around for 75 years,” he said. “It’s made from waste, and it’s fireproof, uses no glues.”
He uses it internally and externally, typically in two layers combined with magnesium oxide board. The system performs well thermally and acoustically — Woodley School, his previous project prompted teachers to comment on how quiet the classrooms were.
Efron suffered mold poisoning and became seriously ill from it, Bakker said. In a location receiving three and a half metres of annual rainfall, moisture management shaped every decision, Bakker said. All pods are elevated off the ground, louvres provide cross-ventilation, and materials were chosen to breathe.
“Durra Panel and hemp — they can absorb water, but they can release it as well. A house is no different from a human being. If you put wet weather gear on and it doesn’t breathe, you start to sweat.”
The Full Material Palette
The external finish on the Efron house is a 100% natural cork spray by Diasen manufactured in Italy from wine-cork waste. It is breathable, fire-tested, and provides a rendered appearance, Bakker said. Roof insulation is New Zealand wool.
Flooring is recycled-brick tile from Melbourne embedded with stripped copper wire grounded to the earth. “Zac loves to walk barefoot,” Bakker confided. Bakker has used it on several buildings to keep occupants connected to the earth’s magnetic field.
Plumbing uses copper for water lines and recyclable polyethylene rather than PVC. Joinery will be produced using a plant-based circular resin from Dutch company Plantics.
Joost Bakker (L) and Zac Efron (R) from Instagram
Off-Grid by Design
The solar array is assembled entirely from tested and tagged second-hand panels sourced through Lotus Energy in Melbourne, which recovers and recertifies panels that would otherwise be discarded. “Some of them will definitely last another 20, 25 years, so why would we use new?” Bakker said.
Rainwater is harvested from the solar pergola roof directly into tanks. Wastewater feeds a worm farm, which in turn supports an on-site food system including stone fruit and Kakadu plums.
Green roofs are standard on all Bakker’s buildings. At the Efron site the roofscape forms part of the living system rather than a surface to shed water from.
The result is a building with no element that hasn’t been assessed for its end-of-life sustainability.
“I wanted to build a natural house with natural materials and recyclable materials,” he said. “I don’t use materials that can’t be recycled, basically. A lot of things that go into normal buildings, I refuse to use, because at the end of the life of the building, I consider everything. So if it can’t go into a recycling bin, can be easily recycled or locally recycled, I just won’t use it in a build.”
The home will showcase many natural and bio-based solutions already available to builders willing to look for them.
Joost Bakker appeared on an iHemp NSW webinar on 23 April 2025. Listen to the replay here: https://ihempnsw.org.au/news/23-april-2026-webinar-joost-bakker/ Find out more at greenhousebyjoost.com.
