Architect's Hempcrete Home is a Blueprint for Better Building

In the world of alternative architecture and natural building, hempcrete homes were one of my very first loves. And today we're about to visit a beautiful small home that reminds me of just why that was. Hey Michael, it is so good to see you again. So nice to see you after all this time. It is alarming and actually terrifying that it has been eight years since we were last here. We're getting old. Getting old, I have all the grey in my beard now. Yes, I have a tiny little Chinese goatee there. But it is amazing to see that you and your family are absolutely thriving here. Yeah, we've been having a lot of fun over the years. Going from a little tiny home to a slightly bigger home and then creating something like this up here on the top of the hill. Yeah. So you were in the original Skyfarm for about five years? Yeah, we lived in there, the four of us, for five years. Comfortably happy. We had a little sea container that expanded into our first little office. The intention was only to stay there for six months. Right. Inevitably, six months turned into five years and it wasn't really a problem for us. Yeah. And you've now built your new home, which is really beautiful. Yeah, 2.0. All based on the principles that were created in that first cabin. When we built that home, it was about an experiment of new materials and new ways of building healthy. And we've taken that into these two new buildings as well. So all done with hempcrete? All with hempcrete, yeah. All of the walls, you know, north, south, east and west are all hempcrete. Because when we first met you, hempcrete was a very kind of new concept and it was something that a lot of people hadn't heard of at the time. But now it's just getting more and more popular, isn't it? Obviously, testament to just how good of a material it is to build with. Yeah, I mean, in this country, the last decade has seen rapid growth. But globally, the growth has been even bigger. America, Europe, there's thousands and thousands of buildings. Commercially, they're spraying it, making panels, making blocks. In Australia, we have seen some growth. It's still slow and steady, but projects like this become a little example. And once people can touch and smell it and see it and come and stay in places like this, they really understand it. Yeah. And so for those who have never heard of hempcrete before, tell me a little bit about it as a building material and what makes it so good. Key characteristics are it's carbon negative. In this subtropical climate, it's really great for managing mould. It's made with a lime binder and that lime sits at a pH of 12 and a half. Mould can't grow on anything above four and a half. When the climate is so damp like it is here, it's a wonder product for healthy building. It's also flame zone resistant for bushfire. It's termite resistant. It's easy to build with. It's lightweight. It's 100% natural. And of course, for you, the most important aspect of all of this is that you're building healthy human environments. Yeah, exactly. Anything that's healthy is good for the environment as well. Yeah. But we started these projects with the challenges that we'd had from a family sickness. Made us really aware of what building materials can do to the body. And that led to a lot of recycled timber, untreated materials, less toxic paints, less oil-based finishes, low VOCs, trying to manage the EMR and ultimately the hempcrete. Yeah. And tell me about your new family home. Yeah, well, the new family home is bigger than the little cabin, thank goodness. But it's still only like 170 square meters. Yep. But we've used those same principles of mezzanine spaces. So in the large open plan space, we've got a mezzanine that looks down into the living room, similar to what we had in that first cabin. The bedrooms also have little loft spaces. We kept the rooms as small as we could because we wanted a small footprint. And the kids' rooms are like three by 2.8, but they've got a little loft space above the bathroom and the laundry. So for us, it was about designing as compact as we could, but using the height and volume to create that sense of space in there. But all the same natural materials, hempcrete, large gables facing the north, so we can bring in that winter sun, which is really important. And that project's actually a slab on ground, which is different to both these cabins. Fantastic. And the space that we're exploring today, this is very much an experiment for you in really small, simple, healthy home building. It is. And it was also an opportunity to be the first to put hempcrete in the floor, which hadn't been done in Australia, and I don't really know any other projects that have done it. And what it does is it allows the entire envelope to be hempcrete. It also makes the floor feel a little bit more solid rather than being a suspended, thin timber floor where you lose a lot of heat. So it gives us a little bit of thermal mass. And when you've got that winter sun coming in, it manages to keep the space really warm in the winter. And first of all, the position of this cabin is absolutely extraordinary. Your property is so beautiful anyway, but from right up the top here, you get the full effect of this amazing vista. Yeah, it's very different to 1.0, where you're in the fields and in the paddocks with the cows and the animals, but up here you're perched up like an eagle at the top. So what's the size of this cabin? So the actual cabin internally is 55 square metres. We've got a 20 square metre deck out here facing north, covered of course. So it's compact. Tell me about the construction process of building a home like this. Yeah, so we're trying to minimise the cut and the fill. So we perched it up here on the flattest part of the ledge, put some piers in and create a sub floor. And then we created a working platform with an OSB base. From that, we started to build the wall frames and we've included as much recycled material as we could, especially because it's durable, it's low toxic. It's also sourced locally as well, which is nice and easy. And then when we built the framework, we put the roof on and we got a load of volunteers in and we ran a little workshop. Yeah, so it very much fits into that traditional kind of earth building model where the materials are actually really affordable, but there's a lot of labour involved in the construction. So it's good to do it in that kind of workshop environment. Yeah, it is. And also you learn, you know, we had people who wanted to build with it come and volunteer for a couple of days and it's the best way to teach them how to do things. For instance, we permanent formwork the outside and we packed it from the inside, skipping up 600mm formworks. That was a much easier, safer way. Didn't need scaffolding outside. Everyone's in an internal environment under a roof when it's always raining. One of the things that I love about hempcrete as a material as well is that unlike other building materials that degrade over time, hempcrete actually gets stronger and more robust over time. Yeah, it continues to sequester carbon for up to 30 years. So as the lime is slowly carbonating, it's sucking carbon out of the atmosphere into the wall structure. Yeah, and it's almost like it's becoming more and more closer to stone over time, isn't it? It is, it gets harder and harder over time. And you are off the grid here as well, aren't you? We intend to be off the grid ultimately, but we've provisioned for it. So we've got 15 kilowatts of solar and 30 kilowatts of battery. We will expand that solar system towards the other buildings as the property grows. We've maintained a grid connection for now, but the plan is to go off grid. Well, even if you do go off grid, it's actually nice just to have the backup and safety of the grid connection as well, isn't it? It definitely is, yeah. And around here, power is patchy, especially in those stormy events and floods. So it's good to have both options. But I really love the fact that we're generating our own power here that's feeding these three buildings and possibly future buildings. And it really is so cool to watch the way that your property is evolving here. What's the ultimate vision for this place? Yeah, when we started, it was always going to be a multi-generational farm with affordability issues happening globally. I see it as a place where my kids will grow up, go to school in this environment and then leave, fly the nest for a decade, go and live in cities or internationally. But a lot of people seem to come back. Yeah. And it's nice to have a place to call home. And these two small little cabins will be their start offs and hopefully they can expand from there. I really love that. And coming together as a family to share resources, especially in this day and age, just makes so much sense. Yeah, it does. I mean, land values in Australia are going crazy. And to have the land and make the best use of it is sensible. And this is really just the start of the master plan. The dam's gone in, there's proposals for future building structures, maybe offices to arrive here. So it will become a little family enclave. So in another 10 years, we'll be seeing something completely new here. True. Whether I've got the energy to build it all, I'm hoping they will take over that. Yeah. And they will bring their stamps and their design ideas and hopefully build off the back of what we've created. I love that. Yeah. And obviously you've created a structure here that is so practical, but it's also so beautiful. And I just love this area, especially that you've created out here with the bathtub. And what a place to just soak in these views. Yeah. I mean, the deck in a north-facing Byron Cabin is really important. I mean, this is where you connect to the view. And having a little bath there where you can soak up the atmosphere and at night, it's a beautiful experience. So here is where the parties happen. Here's where the entertaining happens. And it's very Australian. We've also got a little bit of privacy because there's a road. So we've got planting happening around us. But this is really where the fun part is. Yeah, absolutely. I love the look of what you've created here with this cabin. And I cannot wait to see what you've done on the interior. Can we step in and take a look? Let's go. All right. This is brilliant. And I really love the way that you have celebrated the materials in here with all of this exposed hemp. It's raw and it's as it was when we took it out the formwork. And I kind of love it. It's an opportunity to show people what the material really looks like. We have a rendered wall section as well. But I think the off form has character, has life, tells a nice story. It really does. And I love the way that you can sort of see the layering in the walls as well and how all of that's worked. Yeah, you get more layering when you have more volunteers as well. Yeah. Too much water, a little less water. It kind of exposes the different pores that the groups have put in. But it's a lovely touch. It just creates so much visual interest. And it, I don't know, it almost makes it feel a little bit cave-like, doesn't it? You sort of get those beautiful, darker, natural colours coming in. Yeah, you do. And this is the original hemp herd that was produced in Australia in Hunter Valley. And it's a slightly larger chop. So you get a little bit more texture and roughness with it. Our walls these days are a little bit more refined, a bit more packed, a little bit finer. How easy is it to source hemp in Australia now? It's reasonably easy. There's farming co-ops all over the country. There's one in Tasmania. We currently get product from Ashford. This was from Hunter Valley. Yeah, fantastic. And the layout in here, so simple, but it works so well. Tell me about what you've done here. Yeah, so the floor plan is this open living room, dining room space, obviously addressing the northern aspect. For me, it's really important to get that northern sun and warmth in through the winter. The overhangs protect you all through the year and the summer and the rest of the warm months. We've got a bedroom area that, as I said, we originally designed for a wall to come through where that beam is and separate these spaces. But as we were building, we were like, hey, it's nicer as an open space. Yeah. Little en suite out the back, which has doors to open up into a southern courtyard. Really important for me was to keep the kitchen low and nicely designed and not feeling like you're living in a kitchen. Yeah. Tell me about the kitchen design. So everything in this house was made around cost efficiencies and recycling materials. So we had some recycled timber that we biscuit jointed together. It was really simple. We sanded it down and then we just finished it for the countertops. The cupboards are made in plywood. So simple to put together and then just oil finished. Couldn't have MDF in a place like this, could you? No, no, no. Those materials were chopped out a long time ago. Yeah. Nice. Beautiful floors in here as well. Yeah. So this is a mixed hardwood, but we've used a ruby monocoat finish on top, which is a nice matte finish. And tell me more about how the hemp flooring is working here. That is a unique design idea that we came across as we were building it. And to build off it, we had a working platform OSB layer that sat on top of the joist. We then packed out that OSB layer with 90 mil studs. And then we filled in between that with a very loose mix of hempcrete and then put the timber over the top. So it really is just acting as an insulation layer. There's nothing structural in it. That's correct. Lovely relationship between the kitchen, the dining space, the lounge, and then all just focused out onto that view through the massive windows and doors there. Yeah. Really important for us to always be connected to nature and this stunning view. And the flow from the kitchen, dining, living room is really important. We've got this cosy little living room space that's always addressing the room. This is a beautiful French oak door that we found and salvaged and turned into a coffee table. And it's a lovely, cosy space to sit and read a book throughout the day. Great artwork in here as well. Your wife, Tiffany, did this, didn't she? She did. She's an avid artist and these are some of her masterpieces. We thought it was a nice touch to the space that we've built as a family that we then decorate as a family. It's really nice to sort of have that textured wall and then the art actually really pops on it, doesn't it? Yeah. Hempcrete makes a wonderful art gallery space. It does. People were worried about fixing through it, but it's absolutely fine. Lovely high ceilings in here really contribute to that sense of spaciousness. Yeah. So we like to use passive design principles in all our projects. So you will see the high ceiling facing north bringing that northern light in, but we'll also have hempcrete walls on the east and the west to buffer from that heat gain that happens throughout the summer. And then hempcrete on the southern wall to minimise the heat loss through the winter. Very sensible. And then over here, we've got the bedroom. Yeah. The bedroom is a beautiful space set with a hempcrete wall behind you. The little hole that you see there is actually, during construction, birds flew through the door and kind of nestled there, made a little nest in the wall there. And we didn't have the heart to remove them, and we just let them do their things. And when the project was left, there's a little nest hole there. Oh, I love that. Cute. Love the use of the support beam here as well. That's become quite a feature. Yeah. We had some of the beams left over from the other build. And what better place than to separate and define the space between the bedroom and the living room with a beautiful cowrie beam from Western Australia. Very unusual furniture in here as well. Yes, I will acknowledge that was from the mother-in-law. That was her gift as we finished it and blew the budget, so she donated the bed and the bedsides, but also the bed settings and this French oak log ottoman that we created along with the coffee table. Really nice. Unusual wardrobe space as well. Yes, that was a Japanese antique that we bought in Sydney many years ago. We put it in here as a kind of backdrop. It's old, lightweight Japanese furniture that would normally sit in a living room and really efficient for storage. The French doors there opening up right to the hot tub. That's a nice touch. Yeah, it's a really lovely experience to be able to flow from your bed, open the hinged doors and relax in a bathtub with a book. Absolutely. And everywhere that you are in this cabin, you really get this space of height and the sort of drama of the views and the landscape. Yeah, I mean, architecture is easy when you've got a backdrop like this. The view was the most important thing and being perched up here at the top of the property was really important to get that feeling. Yeah, all you have to do is frame it. Exactly. And then behind us here, we have the bathroom. Can we have a look in there? Yeah, let's go. All right. Oh, this is great. Fantastic door here. This is packed with character. Yeah, another French oak door brought in from Europe that we found salvaging. Turned it into a kind of fortress-looking bathroom using recycled material for the doors and the bench tops and then having these French doors that open out to a southern courtyard was important. Very nice. And then brilliant tiles in here as well. Yeah, these are actually quite cost-effective local tiles that we found in a sale. They're a travertine lookalike porcelain, so they're a lot more durable. And very cool timber on the ceiling as well. I really like that look. Well, I'm glad you think so. Many other people do, but it's actually a mistake. Oh, really? Yeah. During the construction, I was supposed to put a primer on before I put the paint on. And in the tiredness, I forgot to. It's now peeling and rustic and everyone loves it. We'll just call it a happy mistake then. Exactly. Yeah, nice. Very simple design with the bathroom here, but it's got everything you need, even the washing machine here too. Yeah, it's important in a small space that you put all the necessities in there. So having a laundry in the bathroom, a little bit European, but it's a good use of space. Very much so. So obviously you've been really busy here on your own farm and building amazing projects like this cabin, but you've also been working on some other really exciting stuff. Yes, our business grew significantly after that first cabin that we built as kind of an experiment of our work. And over the last eight years, we've done 50 to 60 local projects. We've probably designed 200 in the country. All using natural materials, all based around hempcrete and its wonderful properties. And hempcrete isn't just being used in smaller, quirkier projects. It's also becoming really popular in some quite extravagant builds. Yeah, we're starting to use it commercially. We did a local school here. That's all with hempcrete and magnesium board and a clay render and a lime render. It's being used and sprayed in other larger brewery type projects internationally. Bread and butter is still in the residential market. So in the same way that we used it in this house, we're using it in others. Yeah. And ultimately, this is a result of people becoming more conscious of the spaces that they live in and making sure that they are inhabiting healthy environments. Yeah. Wellness and indoor air quality and the toxicity in our environment is really important these days. People are going to the gym and they're eating healthy food and they're realising they're living in spaces that could be better. I think it's one of those things that we don't really think about. You go to a Bunnings or you go to a store and you buy something off the shelf and you sort of assume that what you're buying is safe. But really, a lot of the safety testing that goes into a lot of the materials that we sort of put into our homes really without much thought, they really are quite questionable. And even if it's sort of low VOCs, low emissions, low levels of toxicity, and when we're putting them in spaces where we do spend an alarming amount of time, over time, our exposure to those things really can have a significant impact on our health. That's right. It isn't the short-term exposure. It's the long-term exposure to low levels that can be a challenge. We find in our designs, bedrooms are really important. You spend so much of your time sleeping. So we try and make those environments really healthy, good air quality. So they'll always have hempcrete in the walls. We'll try and keep EMR low, no GPOs either side of the bed. So you're trying to create a space that you can really get that restorative sleep. Yeah. You're an architect, but you also spend a lot of time with building biology. What are some simple things that we can do to make our own living spaces better? Yeah. Key materials, things like paints on the walls are an easy go-to. If you can go with the lowest VOC and natural paint, and there's some great products out there in the marketplace, that's a good starter. Having good light and ventilation, no-brainer, very easy to do. Louver windows, making sure you put windows in the north side, or adding windows into an existing building that will bring that northern light in, which will help create a better environment, mitigate mould, and allow pathogens and other bacteria to be extinguished by the light. Yeah. Or of course, southern light if you're in the northern hemisphere. Of course, yes. And if we take it away from practicality and materials for a moment, as an architect, you spend so much of your time designing spaces that just really work for people. What are some of the really simple things to keep in mind during your design process to make sure you're designing a space that'll work for you? We always start with a site analysis and orientation being the key. There are positive material choices and there's negative material choices, and often it takes a little bit of research and a bit of a deep dive to understand what's really in those products, to understand what choices we should make. We've talked a lot about what makes people healthy in their homes. What makes people happy in their homes? For me, it's always a connection to the natural environment, whether it's going for walks, whether it's sitting on a deck or sitting on a chair, connecting to the wonderful healing qualities of nature. What I really enjoy is in our spaces, you feel like you're connected to nature internally. So these walls, they're kind of like living. The first cabin was done with clay. These ones are done with lime, and these materials change over time as we change. It's a living being. It's not just an element that you exist in. This is such a unique and interesting way of building, and there's so many quirks to a structure like this. Can we talk about the cost that was involved in building this cabin? We built it ourselves, so it was a little bit more efficient in terms of cost. A building like this would be about $5,000 a square metre-ish. Wow. Pre-COVID, we built this for just under 200 grand. Yeah, but a great result. And it just goes to show as well that for really not much cost difference from building conventionally, you can actually go the extra mile and do something really unique like this. Yeah, and I think that's design that makes the difference. It doesn't necessarily have to cost a fortune, but if you've thought through the environment that you're building in and you've thought around the solutions, then you can make a wonderful piece of architecture on a low budget. Yeah. Already, what you've created here on the property with this great multi-generational living setup is really inspiring. Tell me about what the future holds for you now. Yes, the future is to continue the development from inside the fence to outside the fence. This is a 30-acre property. We've got visions of creating food farms, orchards. We're going to have some organic cattle here. We've recently put a dam in, so we've got a permanent water source from all this wonderful rain that we keep receiving. So forest regeneration, managing land, understanding what the soil needs is a really important part of our work as well. And you're also making some amazing headway with your healthy building advocacy work as well. Yes, we've started to do a lot more presentations and educational work into the corporate world. Everyone realizes wellness is a big part of a future trend that's happening. And we recently did a presentation with Metricon, who are trying to take some of those ideas into their volume home building philosophies. So it's exciting to see that mainstream is starting to consider the work that we were doing 10 years ago as really important and relevant. Yeah. What would you love to see change in the building industry? It is hard. We have to do performance solutions for hempcrete because it's not accepted under the NCC. So clients are lumbered with the additional costs of reports. Rammed Earth is also a performance solution under the NCC. And certifiers, whilst they are accepting it with enough education, enough information, anything that's out of the box is still hard work in Australia. And I think educating some of these larger corporations and larger businesses on the benefits of these will help us grow a critical mass that can hopefully make these things more widely acceptable. If we're going to manage the carbon issues and the health issues that we have in some of our buildings, then codes and practices need to change. It'd be great as well, because if they took on more of the responsibility of building healthy homes, then they could also help with the cost of certifying these materials so that it can be more widely used. Absolutely. There's a misconception that building alternatively and naturally is more expensive. There is a little bit more labour in it, but there are efficiencies. And I think with technology and smarter minds coming together on how we can deliver these things, there are ways to make these things more readily available to everybody. I love that. And bringing it back to you and this being your home, tell me about life here together with your family. It's been wonderful. My kids have grown up in these natural environments. They've actually had a hand in building all of these projects as well. Coincidentally, my oldest one is considering studying architecture. Great. The other one is also a real maker and a builder and a constructor of anything he can. So I feel the project has taken a life in them as beings as well, which is great. I'll be excited to see what they can do in the world themselves. That is really exciting. Well, Michael, I'm just, again, so inspired with everything that you're doing here. This property has beautifully and dramatically grown since I was here last, and I just can't wait to see what you do with another eight years here. Thank you so much for sharing your wonderful home with me. Thank you very much for allowing us to share it with you. We started building homes for ourselves as shelter from the natural world, but somewhere along the way, it became separation from the natural world. And what projects like this remind me so beautifully of is that it doesn't have to be that way. We can build our homes to become part of nature, spaces that are healthy, not only for the planet, but also for us as human beings. And what Michael is doing here with these beautiful hempcrete homes, I just think is a wonderful reminder of what's really possible and what architecture can do for the world if we work collaboratively with nature and not against it.