He’s known for his zero-waste mantra. Now Joost Bakker is turbo-charging it – for his mum

This story is part of the November 30 edition of Good Weekend.See all 15 stories.

Joost Bakker appears at the front door looking like a man who works the land, in worn jeans, a plaid shirt, steel-capped boots and a ready smile. While there’s something of the Peter Pan to his energy levels, he’s recently turned 50, and his weathered face and muscular hands suggest someone who’s not spent a day behind a desk in his life.

Famous for the zero-waste mantra he’s applied to everything from his unusually arresting floral arrangements to the restaurant pop-ups he’s launched over the years, this is Bakker’s biggest leap yet – a house designed and built using many tonnes of agricultural waste and by-products. A house built for his mum, Lia.

It looks relatively conventional, but that belies the fact that this house represents a radical rethink of what it means to live sustainably. It’s an ambitious demonstration project for a new kind of construction, designed to restore and enrich the natural environment instead of exploiting and degrading it. If scaled up, its materials could sequester millions of tonnes of carbon, support thousands of new local manufacturing jobs, help farmers stay viable, eliminate waste and, for bonus points, help biodiversity. I’ll say it. It’s revolutionary. And without a single hair shirt in sight.

The house in question is in the farming town of Monbulk, an hour east of Melbourne. It’s where Bakker grew up, and still lives, now with his wife Jennie and their three kids. As he leads me past the utility room, through the kitchen and into the dining room, he tells me about straw, hemp, biochar, timber, resins and soils, and how to turn all those materials into a home. It’s my second visit; Bakker had an open day in November 2023, when the house was mid-construction. A single post to his 73,000 Instagram followers was all it took to have the house crawling with fellow travellers, all eager to know more about the nuts and bolts, literally, of what makes a house genuinely sustainable. Together with his builder and architect, Bakker spent the weekend sharing everything he knew, providing suppliers’ names, technical information and handy hints on how to avoid mistakes. Each material choice and design decision was tethered back to his life ethos of wasting nothing.

Joost Bakker with his mum, Lia, in her new home.Credit: Josh Robenstone

The two-bedroom home is not quite finished; curtains and a few other home comforts are still on order and the garden has barely been started. Yet already it’s very comfortable, and surprisingly normal-looking. With a U-shaped floor plan, it has a dining room and master bedroom in one leg, the living room and second bedroom in the other, and a galley kitchen and bathroom in the middle. It’s raining and windy outside on the day I visit, but inside it’s quiet and warm, despite there being no obvious heat source. No fire burning or radiators running; just high-performance insulation and solar-powered underfloor hydronic heating.

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Joost Bakker has had dirt under his fingernails since his childhood on one of the many farms around Monbulk. His parents, Joop and Lia Bakker, came here in 1982 from the tiny Netherlands town of Rustenburg in the North Holland province, with eight-year-old Bakker and his four siblings in tow. “At first, we actually wanted to go to New Zealand,” says Lia, sitting opposite me at the dining table in her new home, drinking coffee. “But Joop was 49, so too old for New Zealand because they had an age limit of 45 for new arrivals. So, we had to come to Australia because the limit here was 50.”

Joop built a successful business growing tulips, liliums and freesias. He would have liked Joost to join the family farm, but his son had his own ideas. In the mid-1990s, he started a business buying flowers wholesale and shipping them around Australia and globally, from New Caledonia to the Philippines. “Then I was at the Chevron club in St Kilda and met this guy, Tony [Leonardis], who wanted to start a business selling mushrooms. I was just about to go overseas, but we agreed that when I got back, we’d rent a warehouse together. So we ended up renting a place in South Melbourne. We set up a cool room downstairs, and turned the office upstairs into an apartment. Tony was the first person to bring new varieties of mushrooms from all over the world to Melbourne.”

Young Joost, aged 9, with his father, Joop.Credit: Courtesy of Joost Bakker

At first, Bakker was selling flowers to anyone and everyone. “Back then I felt that every office and restaurant should have flowers, including McDonald’s,” he says. “So I just got on the phone, and it took me 18 months of calling every week, but eventually I got the McDonald’s contract. At one stage, I was supplying live flowers to 130 McDonald’s stores.”

Meanwhile, Leonardis’ business was doing a roaring trade. Chefs would drop by to pick up a box of yamabushitake from the “mush-room man” and leave with some of Bakker’s peonies, too. The business grew, and as he delivered flowers to his regular clients, Bakker often noticed last week’s plonked carelessly in old vases. He convinced some restaurateurs to let him do the arranging. Here, his passion for flowers overlapped with his love of scouring junkyards, and he began weaving odds and sods, like pieces of wire, into his flower installations. For almost three decades, Bakker created bizarre and baroque sculptural flower installations for some of Melbourne’s finest restaurants. Think punk ikebana.

The archetypal polymath, Bakker has since explored a range of new but connected creative areas. At any given time these days, he might be designing a new campus building for Woodleigh School on the Mornington Peninsula, working with material manufacturers to fine-tune a new building product, travelling to Sardinia to verify the credibility of a source of upcycled waste, or experimenting with ways to convert plastic waste into energy. But selling and arranging flowers remains his north star. “We are lucky to have a small farm here in Monbulk,” he says, “and once a week, I head into the city and bring flowers to a bunch of regulars.” Those regulars include Stokehouse, Rockpool, the Gin Palace, Spice Temple and other A-list restaurants.

The first house Bakker built was a two-bedder in Monbulk for himself and Jennie. It was 2006, and born of a frustrating conversation with an architect about why he couldn’t use compressed straw the way he wanted. “I was talking afterwards with [the Melbourne architect] Nonda Katsalidis – he just shrugged and said, ‘Forget about it, Joost. Just design your own house.’ He was the one who really kicked me to do it myself.”

Joost and Jennie Bakker’s Monbulk home.Credit: Ken Irwin

A little over a year later, Bakker’s home was completed, designed exactly as he wanted it. While there’s now a growing interest in recycling and reusing materials, at the time his house was a breakthrough project, made of compressed straw, recycled concrete, plywood and steel. Some external walls were lined with a grid of reinforced steel bars that held hundreds of terracotta pots and plants. He’s since sold this flower wall system internationally, including one to Google for its California headquarters.

For Bakker, the use of straw in particular is both practical and ethical. As a waste product, it’s cheap; that’s why the Dutch have used it as mulch for centuries to protect winter bulbs from freezing. The bigger ethical issue relates to waste in farming. Millions of farmers around the world grow cereal grasses such as wheat, oats, rye, barley and buckwheat – the stalks of which make up straw. At the end of the season, some of this leftover straw is used for animal feed or composting, but hundreds of millions of tonnes of it are just wasted, often burnt. Finding a secondary use for straw is a massive opportunity for tackling climate change.

Bakker’s journey into housing and sustainability would not have been possible without an earlier transformative moment related to an old book he was reading in 2000 – Nutrition and Physical Degeneration, by Canadian dentist, Weston A. Price. Having spent years studying indigenous diets from around the world, Price concluded in that 1939 book that diet, nutrition and health were in decline in the West.

This drove Bakker to explore the relationship between farming practices, the degraded nutritional value of food and human health. “Back then, Price realised that reduced levels of magnesium and calcium as well as fibre and other important micro-proteins in our foods were leading to poor health,” notes Bakker. “That problem is even worse today. American soils have lost a lot of their fertility, as have Australian soils. It’s a disaster for our health. That body of work inspired me to create Greenhouse.”

Greenhouse was a series of public restaurant ­pop‑ups in Melbourne, Sydney and Perth designed to connect nutrition in food with Bakker’s passion for recycling waste. Each Greenhouse featured a host of recycled materials, reused timber and repurposed crates. The first, Greenhouse Federation Square, opened in Melbourne in 2008, followed by Perth in 2009, Sydney in 2011 and Melbourne again for the 2012 Food and Wine Festival.

Greenhouse, aka Future Food System, in Melbourne’s Federation Square.Credit: Wayne Taylor

In each case, there were no waste bins. Bakker converted used deep-fryer oil into an energy source, made staples such as yoghurt and butter on the premises, and milled flour for pizza each day. Old conveyor belts were used as flooring, irrigation pipes were repurposed as chairs and old bottles were cut in half, polished and used as glasses. Each Greenhouse was trademark Bakker: rigorous yet fun. Its success emboldened him to set up a cafe in Melbourne called Silo in 2012 – Australia’s first waste-free permanent eatery. He turned this into Brothl in 2014, transforming waste fish and animal bones from top restaurants into delicious broths. Over about a year, he saved nearly three tonnes of the stuff from going to landfill.

While each Greenhouse pop-up was a step in the direction of more considered interiors and fit-outs, Bakker wanted to give his designs a more permanent afterlife, which was where his mum came in. “I was living on the family farm, and it was just too big,” says Lia, whose husband Joop had died in 2012. “And the family home was too large. So I told Joost that I wanted to move and downsize.”

‘I’d call most of the housing built today temporary housing.’

Local Monbulk builder, Nathan Schroder

Bakker had a brainwave. Why not design a demountable pop-up at Federation Square? When finished, it could be taken apart and shipped to Monbulk as Lia’s new home. The Federation Square project, rebranded Future Food System, was a three‑storey, self-sustaining home for two that could not only provide shelter but also produce food, generate energy and be zero-waste. It harvested water and energy and used both to grow herbs, vegetables and mushrooms. Its simple stack of blocky forms and black corrugated skin gave it a utilitarian, stylish look, with the help of sustainability architects Breathe Architecture. A mash-up of end-of-world prepper, inner-city hipster and nonna’s Babylonian back garden, it was host to events, parties and dinners for nearly two years.

Bakker had an offer to buy the three-storey structure, which he accepted, necessitating the design of a whole new house for Lia, on which he worked alongside the design team of Bronwen Main and Frank Burridge of Main Studio, and local Monbulk builder Nathan Schroder.

Right on schedule, in walks Schroder: a wiry, earnest-looking man padding across the polished concrete floor in thick woollen socks, bearing gifts of homemade fruit cake and oatcakes. “I’d call most of the housing built today temporary housing,” says Schroder. “We actually have two different building industries. There’s the volume-built rubbish, and then there are homes that will last.”

UN-Habitat, the United Nations Human Settlements Program, estimates that worldwide, by 2030, we will need new housing for 3 billion people. That’s nearly 100,000 new homes every single day. If we build housing at anything like that rate in the same wasteful, power-hungry and disposable way that we do today, we will torpedo any chance of turning the corner on pollution, climate and the environment.

The cabinets were made from compressed hemp, which Bakker describes as “crazy-strong”.Credit: Josh Robenstone

This global need for a massive housing program is important context, illustrating why housing experiments such as Bakker’s really do matter. The embedded carbon footprint of standard housing needs to be rethought if we are to curb global warming. Estimates vary wildly, but for every average family-home build, somewhere between 20 and 80 tonnes of carbon dioxide are released into the atmosphere. Frank Burridge estimates that Lia’s home not only reduces its carbon footprint, but is actually carbon negative.

While the house is essentially a steel frame with a concrete floor (both high emitters of greenhouse gases), this is countered by internal walls and ceilings lined with carbon-sequestering straw panels. The external panels are magnesium-oxide board (a by-product of the steel industry) and all cabinetry is made from the super-sequester champion, compressed hemp. The house is fully off-grid, with hydronic heating embedded in the concrete floor, which was poured over a system called Cupolex, an interconnected grid of domes made of 100 per cent recycled, non-toxic polypropylene. This creates a permanently cool, self-supporting void under the floor, allowing warm summer air to be pulled through it by extraction fan. The roof garden, containing nearly 50 tonnes of soil, keeps the house cool in summer and warm in winter.

The vital role of soil in building sustainable housing is often overlooked, says Bakker, leaning forward to make his point. “Did you know that southern Australian forests absorb much more carbon than the Amazon? Because eucalypts don’t have a big canopy, they allow lots of light through, so you get this rich understorey of ferns and other plants. Yet if you walk through the Amazon it’s pitch-black, even in the middle of the day. So there are lots of studies that show that the rich soil biology in Australian forests, thanks to the low density of the canopy, absorbs pollution and carbon at a very high rate.”

Roof gardens are not just about keeping the inside of a house cool (which they do), but also their carbon-munching potential to reduce greenhouse gases. A million new homes with roof gardens would be like a whole new rainforest right here in Australia, Bakker contends.

The roof garden of the new Monbulk home keeps the interior cool and absorbs carbon.Credit: Josh Robenstone

Then there’s the issue of biodiversity. Due to habitat loss, insecticides and rabbits decimating local flower populations, many butterflies – like the Eltham Copper Butterfly, found only in central and western Victoria – are now endangered. “We’ve planted a range of flowers on the roof, with advice from Yvonne Duke, who breeds butterflies for Melbourne Zoo. We are hoping that we can get the Eltham Copper populations going again.”

The entire house is sprayed in a black mix of ground-up waste cork and natural resins, creating a high-performance insulating layer. It makes for a bold architectural statement that feels a little like the Japanese art of shou sugi ban, where the surface of cedar is burnt black to protect it against wildfire.

While engineered timber has become the building material of choice in most sustainable projects in recent years, Bakker has misgivings about it. “I think that 100 years from now, we’ll look back at this moment in time and realise that what we’ve been sold about timber being sustainable because it sequesters carbon was only half the story,” he says. “That idea, especially among architects, has meant that we’re losing more old-growth forests now than we ever have in human history. I travelled deep into the Amazon about 20 years ago. It felt like we spent days getting to this particular spot deep in the forest. Super remote. That whole place is now completely gone.”

The only timber Bakker uses is recycled, with Lia’s house benefiting from Nathan Schroder’s collection, salvaged over the past 20 years from demolished old houses in the area. Given the enormous weight of soil overhead, that kind of recycled timber would not be viable as the house’s primary structure. This is why the structure of the house is steel, Bakker says. While it’s not possible now to smelt iron ore for steel without ferocious amounts of energy, there’s a lot of money being spent on green hydrogen to achieve the energy intensity needed to smelt iron ore without using fossil fuels.

Meanwhile, for the cabinetry, timber has been swapped out for hemp. Bakker has big plans for hemp in compressed sheet form; Lia’s kitchen represents his first trial with it and is a collaboration with a small startup called Hexcore. “It’s crazy-strong. Too strong, in fact,” Bakker says of the compressed hemp sheets. “So much so, when the joiners were making the units, they were burning out blades. Sparks come off because it is so carbon-dense. We’re researching different ways to moderate its density and when we do, there will be no reason it cannot swap out timber in almost anything.”

According to a recent UK report on the potential for expanding industrial hemp production, one hectare of hemp can sequester up to 22 tonnes of carbon dioxide a year – a significantly more efficient carbon store than any other commercial crop or forested area.

If prodded, Bakker will tell you about the week he spent with Kanye West [now known as Ye], who invited him to California to look at designing his Malibu home. Or the meeting he had with former prime minister Malcolm Turnbull, who was interested in his work on food, energy and zero waste. Or the house near Byron Bay that he’s building for Zac Efron, whom he met while Efron was shooting Down to Earth with Zac Efron for Netflix. But Bakker is not a name-dropper; he’s more likely to drop the name of a local butterfly expert or manufacturer, sharing the credit for his work with a growing network of environmental innovators.

He’s had his fair share of challenges, too. He had to shut down Brothl because the City of Melbourne wanted to charge him for the industrial digester he installed outside to treat and recycle food waste. He invested in a multimillion-dollar pyrolysis plant to turn agricultural plastic waste into fuel, which it did, until the Environment Protection Authority shut it down. He’s had many planning rejections and logistical frustrations. But his energy won’t be quashed.

We have no choice but to reduce our wasteful approach to housing, Bakker insists. The combination of exponential construction growth and increasing demands to reduce carbon emissions makes it essential. But demonstration projects like his mum’s house need to be scaled up and made market-ready. Thankfully, there’s a growing community of innovators, investors and good people who want to take these ideas and grow them. With a bit more agility and less business-as-usual, governments could help, too. As with everything else in Bakker’s orbit, time is not to be wasted.

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