Natural materials in construction! We recently spent the day expanding and honing our knowledge on the subject at the first event of its kind by the Alliance for Sustainable Building Products (ASBP), held at the National Self Build and Renovation Centre (NSBRC).
The opening talks reminded us of the benefits of natural materials, not only in terms of environmental impact, but also thermal performance. In particular, “decrement delay” can be a huge benefit to mitigate overheating, as it slows down the speed at which solar radiation can travel through the building fabric to reach the inside. The analogy used was like cooking with stainless steel versus cast iron – the latter takes much longer to heat up due to density and specific heat capacity. Natural materials are also much healthier to work and to have in our indoor environments, with low VOC content.
The summit included live workshops. We saw how straw bales can be a relatively simple form of construction that anyone can learn, making it a potentially very affordable construction method if physical labour can be offered through community input. While hemp is getting a lot of attention, miscanthus (silvergrass) is a lesser-known alternative that needs low processing and can grow in low-grade soil, which in turn can make it lower cost too. The NSBRC as a venue made a lot of sense and gave us the opportunity to visit their Retrofit Zone, with lifesize mock-ups of retrofit construction details.
A large part of what we do at Sow Space is the retrofit of existing buildings. While synthetics have their place, where possible we aim to use natural materials for their obvious benefits. Get in touch if you’d like to work with a specialist retrofit architect on your project.
