This summer, University of Bath, UK researchers are constructing a “BaleHaus” made of prefabricated straw bale and hemp cladding panels on campus. Straw is a truly environmentally-friendly building material, being both renewable and a by-product of farming.
The crop used for the straw can be grown locally, and because it absorbs carbon dioxide as it grows, buildings made from it can be seen as having zero, or even a negative carbon footprint. Due to the high insulating properties of straw bales, houses would need almost no conventional heating, keeping running costs low and minimizing environmental impact.
The two story BaleHaus will be made using ‘ModCell’ - pre-fabricated panels consisting of a wooden structural frame infilled with straw bales or hemp, and rendered with a breathable lime-based system. ModCell is made by White Design in Bristol and Integral Structural Design in Bath (other partners on the research project are Agrifibre Technologies, Lime Technology, Eurban, the Center for Window & Cladding Technology, and Willmott Dixon).
Last year, the team helped build an eco-friendly house in six days for the UK television show Grand Designs. All the ModCell wall panels used for the ground floor of the Grand Designs house are being reused for the BaleHaus at Bath.
Professor Pete Walker, Director of the BRE Center in Innovative Construction Materials at the University of Bath, said: “Up to this point straw bales have not really been seen as a credible building material by much of the industry, even though straw has always been used in building for centuries, and straw bales have been used for about 100 years.
The BaleHaus at Bath, due to be completed in the late summer, will be monitored for a year for its insulating properties, humidity levels, air tightness, and sound insulation qualities. Dr Katharine Beadle, the principle researcher on the project, explained, “We’re putting sensors into the walls to monitor temperature and humidity levels, and using technology to simulate the heat and moisture generated by people.”
On the BaleHaus website, you can now watch the progress via “Strawcam”.