Dan Rawlins and his partner Chloe Meyer set themselves an ambitious target when they decided to build an off-grid house made from hempcrete and rendered with a horse manure mix, all without ever having built a house before.
And while that might sound like a recipe for disaster, the couple had experience weathering difficulty — literally — after living in a shipping container with an outdoor kitchen through several Tasmanian winters.
"The vision for me is really about having a crack at a sustainable alternative and having a place that feels fun and creative to live in," Dan told ABC iview's Grand Designs Australia.
"It's going to be a fairly comfortable hemp [house]. Not as small as a cottage, but a hemp house."
Dan said the decision to use hemp — a variety of cannabis plant that doesn't contain THC — came about after many hours of research.
"The more I burrowed into the YouTube wormhole, the more it seemed too good to be true," he said.
"[Hemp has] got excellent insulation. It's fireproof, it's mould proof, it's vermin proof, it's vapour permeable.
"It lasts for hundreds of years, it's actually carbon negative so it sequesters more carbon. The actual building will be carbon negative at the end."
A budget boost
Building any house yourself, even those without alternative materials, is a big ask, and Dan was the first to admit that experience wasn't his strong suit.
Luckily his dad, Pete, a career builder, agreed to be the brains to Dan's brawn and keep him company while Chloe completed her studies at Oxford in England.
"Dad's very finicky about details and I'm very … I don't let perfect get in the way of progress, so hopefully that makes a nice marriage for building something that lasts for a long time," Dan said.
Dan bought the block of land near the town of Franklin, about 40 minutes south-west of Hobart, on the Huon River five years ago after scouting the area with his parents.
But it took a few more years for he and his dad to design the house, and for him to save up enough money to fund its construction.
With Dan's tight $300,00 budget, his goal was to build an off-grid house in just under a year that included:
- 30-centimetre thick exterior hempcrete walls
- Double glazed windows
- Horse manure render mix
- Cast iron wood stove
- Composting outdoor toilet
- Solar panels
As well as a breathtaking view of the river, the block also backs onto the forest which bestowed on Dan a much-needed budget win.
A large Tasmanian oak that had toppled onto his property turned out to be ideal timber for the bones of the house, saving him over $50,000 right from the get-go.
"There's not really a more sustainable way to do it. A tree that’s lived its life, fallen over, gets lopped up from a portable mill and straight into the walls," he said.
But as much as fate gave with one hand, it took with a bigger one.
Family heartbreak
Before any work started, Dan's dad, who was meant to be the other half of the two-person building machine, was diagnosed with cancer and began treatment.
"The main part for me is just to keep him focused on being healthy," Dan said.
"It’s super stressful and it puts everything in perspective. I’ve been thinking a lot about it."
Dan forged ahead on the timber stud work around which the hempcrete would be framed.
But in October 2022, all work came to a stop.
"We got the call that they were making the decision to stop treatment and move Dad to palliative care.
"Dad passed away a week later almost to the day. It was just an absolute roller coaster that knocked us all for six.
"It was a hard time but we don't get to call the shots."
When he felt ready, Dan returned to the hemp house.
"He'll want me to keep going and finish it off. I'm not sure that he'll trust that I'll do an awesome job of it," Dan joked, despite his grief.
Dan's Mum, Kerstin, joined him to provide an extra set of hands as he got ready for the all-important hempcrete pour.
Hempcrete goes in
After nine months of building, Chloe returned from Oxford just in time for the mammoth task of laying the hempcrete.
Given their lack of funds, Dan and Chloe relied on the goodwill and energy of keen community members who volunteered to help.
Everyone got a job, and a bucket, to load Dan's hempcrete mix into the wall brackets.
The hempcrete mix was made of the stalks of the hemp plants, lime, a small amount of cement, water and pozzolan, which reacts with the lime over time to cure the mix.
The magic of hemp is that the mix is full of air pockets which makes it breathable but about an eighth of the weight of concrete.
However, mix it wrong and the strength and durability of the walls are at risk.
After it was mixed, the crew spread it in 100-millimetre-thick layers, tamped it down and continued with another bucket.
When he removed the wall braces Dan was greeted with sturdy and cured walls, a sign his mix and the installation was a success.
"It feels kind of surreal to be honest. [For it] to be so long and then suddenly within a period of a couple weeks all your walls just go 'Bang' and they're up."
It took Dan, Chloe and their mighty crew six weeks before all the walls were in and finished.
Horse poo render
Over time, if left unrendered, hempcrete walls degrade when exposed to rain.
"We really need to waterproof the house before winter, so the race is real and we’re up against it, but we’re chipping away," Dan said.
But the render Dan chose included another left-field ingredient — horse manure.
"It's going to be part of the mix that we put in the base coat of the walls.
Thankfully some canny neighbourhood kids have done their jobs for them and at $2 a bag, they were the perfect price for their budget.
When added to a mix of lime, sand and water, the manure fibre adds strength to the render.
And, in case you were wondering, it's relatively odourless, which is no doubt a relief for Dan and Chloe.
By the end of winter, the team got the first coat on and, with the windows installed, the house was sealed.
'I'm sure he'd be super proud'
It took a few months longer and $30,000 more than budgeted, but after 18 months the hemp house on the hill was finished.
Even though he didn't get to build it with his dad, Dan thought he did their dream justice.
"I’m sure he’d be super proud. His parenting style was always let us make our own mistakes. I think he’d be really pleased," he said.
With the exposed internal hempcrete walls around them, Dan and Chloe have a daily reminder of the grit and determination that went into their home.
"We really like that it tells the story of the different people that came to tamp it and the way it moves – that’s one of my favourite parts now," Dan said.
And, after their cramped and outdoor living situation, for Dan and Chloe it's the creature comforts the house offers that were most exciting.
"I think we’re so pleased with where it’s ended up, we’ve been loving getting to know it," Chloe said.
"It’s great to move in and make it more homely and to settle in for the winter especially, that’s quite a nice touch, having a house over our heads."
"The only downside is we’ve acclimatised to a warm house now, it’s too cold being outside. We’ve gone soft," Dan joked.
Stream all episodes of the new Grand Designs Australia series free on ABC iview or watch tonight on ABC TV at 8pm.