Hemp House at Yaapeet 

It was a childhood dream of mine to build this house. 

Growing up in Switzerland I was surrounded by beautiful old buildings that seemed to defy time and just got more beautiful with age. The lime renders, the old timber dark from age, nothing straight, the beautiful windows that seemed to smile. I was also inspired early on by Roman building methods and ways of decorating. In particular I was  deeply impressed by a rebuild of a Roman villa with a courtyard in the centre of the building. Time went on, I became a vet, travelled to Australia and met Gene, my husband, a broad acre farmer in the Mallee. Gene was initially the opposite to me. He preferred modern building methods, straight plasterboard, concrete. So, when it came to choosing a style of house for our new house on the farm it wasn’t going to be easy. 

That’s when Martin Round from Spacecraft Design Build came to our rescue and introduced us both to hempcrete. The insulative qualities impressed us both. Considering we were living in a very hot environment this was paramount. 

The straight walls and neat corners that can be achieved satisfied Gene’s eyes and the fact it was a natural building material and could be lime rendered was good enough for me. 

So, despite all odds, we found our building method that suited us both without  compromise. 

When Martin and John came up with their first design of the house including a  courtyard, I was ecstatic because I didn’t think our careful budget would allow such extravagancy.  

After a lot of very positive collaboration between Martin, John and I we came up with our final plans for the house just before Covid hit. We had to wait until the world returned back to normal before we could start building, which allowed me a lot of time for research into old building methods. 

I learned the art of Tadelakt render through New Age Artisans in Montana who kindly taught me. I built a limecrete bath and Cocciopesto (a natural waterproof lime-based material used since Roman times) vanity for our existing bathroom to practice for our new house. I rendered Tadelakt on all of our existing bathroom walls including the shower. It was then that Gene started falling in love with those beautiful old building methods. 

We ended up going to Liechtenstein to take part in a private course run for us by Andreas Matt, an engineer, who had 20 odd years of experience with clay and lime renders and limecrete floors, his business providing such building methods for the high-end client in Europe. 

He introduced me to Christian Egger’s wall cooling system from Austria. As a a parallel system it is unique and more efficient to standard wall cooling systems. Water temperature to cool the system has to be between 18-20 degrees Celsius, which is much warmer than in other systems. We ended up importing a system for ourselves and integrated it into the clay walls of our new house. 

The internal clay walls are a lath and plaster type system with clay dug out from the building site and sand from our paddocks. 

The external hempcrete walls are cast on site into formwork, the hemp came from Margaret River Hemp Co WA. We were averaging 4 people working on site to mix and tamp the hemp. Our local builder, Mal McLean, with his employee who put up the stud frame and the roof, did the formwork for most of the walls and helped mixing and tamping. I was on site every day tamping or mixing. Sometimes we had volunteers, sometimes Gene had some time to help. Our Fram hand also helped occasionally. 

For the last wall, Martin and John from Spacecraft Design Build brought their apprentices to teach them the art of hempcrete formwork, mixing and tamping. Overall, it took us about 5 weeks for the external hempcrete walls and probably about two weeks for lime rendering the walls, which I did with two French backpackers who learnt on the job once the walls were sufficiently dry. 

For the internal clay walls, we used local clay and sand and fine wood chips left from window making. Mal McLean had kindly put up all the lath. The timber for the lath I had purchased from a trellis making enterprise in Melbourne before it was made into trellises. 

The French backpackers and I were then rendering the walls after having installed the water-cooling system on most of the internal walls with three coats of clay renders from thicker and coarser down to smoother and thinner. At the same time, we were also putting out our limecrete floor. Gene had made a big pan mixer especially for the purpose and we all helped one another mixing and tamping layers of limecrete floor. 

We used limestone gravel from the local gravel pit and lime. For the last coats I use sand and lime. The limecrete floor was very hard to get approval for but eventually together with an adventurous engineer from BSE engineering and Andreas Matt from overseas and my research into Australian road building methods, we got the building permit even including limecrete in bathrooms which was a big win. 

I have just finished installing the windows and doors which I made on site in my wood workshop. For the frames I used old Oregan which came from the Castlemaine flour mill which had burned down at some stage. The massive timber logs were all charred on the outside but perfect still on the inside. I cut out all knots and cracks out of the timber and fixed many of the pieces of timber for the window frames and purposefully used different coloured timbers and stained glass to fix and decorate the frames. It took about 4 months to build the frames. The casement for the windows I made out of new Western Red Cedar timber that I had purchased from Hazelwood and Hill Timber. It took me another 6 or so weeks to make and fit and hinge them. 

The doors I made out of old reclaimed doors one of Gene’s uncles had given to me. I disassembled them, recut the timber, reused the frame but made the doors thicker and made them into a decorative item rather than just a useful part of a house. Every door is different. I used reclaimed timber where I added more timber to the doors. 

The tile art on the clay walls just sort of happened because of my love for beautiful tiles, colours and patterns. Many of the tiles are handmade, from different countries. The decorative bird tiles are made by a lady in England, Noreen Jaafar and feature our favourite local birds. 

We are at lock up stage now but I will still have some work ahead of me. Finish rendering walls, and floors, kitchen joinery, bathrooms but I am slowly getting there and our three children and us are all very much looking forward to finally living in the new house up on the hill. 

Written by: Catherine Fuller