What inspired you to start working with cultural and community projects?
We started making things in London in a very informal way. We worked a lot with our peers and what we were doing was really part of a broader DIY culture within our community. In the absence of institutions that spoke to us, we made our own spaces in which to explore our own culture. This kind of work was only possible under the provision of it being temporary, but serendipitously, almost all the places we built in this era are still here.
We made our buildings in a very hands-on way, going on site ourselves, with friends and volunteers to build a project and used very basic tools and equipment to do so. This experience continues to feed into the work we do now, our understanding of materials and the way we design with others.
More designers are using hempcrete at the moment, and I’m familiar with artists using it on a small scale with pottery and sculpture, but nothing like on your Flat House project. What was the process like when building with this material on a larger scale?
The process began with the drilling of the seeds in the 30 acres of field that surround the house. This was overseen by Joe Meghan, a hemp farmer who had supported Steve Baron the client and founder of Margent Farm in getting a licence and specifying the appropriate subspecies of plant.
Hemp is a very resilient crop, with long tap roots that help to rehabilitate and condition soils that have been degraded through industrial farming practices. It has a short growing season of 3-4 months, after which we were able to harvest the seed and stem and process it into usable oil, fibre and shiv (the woody core of the stem).
The project makes use of each element of the plant, with the oil being used by Margent Farm in health and body treatments, the fibre being made into a cladding and the shiv into the hempcrete insulation. Each element of the plant went through a different process, with the fibre being felted and blended with a sugar resin and the shiv being chopped and mixed with a lime binder.
We designed a cassette-based construction system using structural timber with hempcrete to form an insulated panel, refining the construction details with Oscar Cooper from Lignin Builds. The panels were constructed in a factory and dried before being brought to site and lifted into place over two days. The cladding was made a few miles down the road with the impregnated hemp fibre matt pressed to form corrugations. The cladding is very easy to work with as it’s light and can be cut using a simple hand saw. We were lucky that with so many elements of experimentation, everything went very smoothly, and the building came together as anticipated.