A €1.6million research project is paving the way for the certification of straw bale buildings, setting recognised industry standards for a technology pioneered at the University of Bath, England.
The environmental impact of the construction industry is huge – the worldwide manufacture of cement contributes up to ten per cent of all industrial carbon dioxide emissions.
The use of straw could help the UK achieve its targets for reducing carbon emissions. Straw is the ultimate environmentally friendly building material since it is renewable and can be grown locally to the development. It absorbs carbon dioxide as it grows, meaning as a construction material it has a zero, or even negative carbon footprint.
Balehaus, a two-storey prefabricated straw bale and hemp clad building on the University’s campus, was developed to explore the properties of this low-carbon material, and has been closely monitored by architects over the past two years.
This funding, made available through the European Commission’s Executive Agency for Competitiveness and Innovation, will address the EU market development of the ModCell pre-fabricated straw panels used in Balehaus.
ModCell panels consist of a timber structural frame infilled with straw bales and rendered with a breathable lime-based render. Through certifying their use as a construction material and scaling up the production of these panels, the research group aims to ensure the widespread development of straw bale buildings.
Professor Pete Walker, lead researcher, said: "Our research team has measured the moisture content and humidity levels of the straw in Balehaus, and the temperature within the envelope of the building over the last two and a half years. In all cases to date the building has met or exceeded requirements, so we’re confident that in the current design of the building and the materials we have are a durable, long-lasting solution.
"However, although a number of other straw bale developments have emerged since we built Balehaus, until now these have all been public buildings. For this technology to be extended to domestic dwellings, insurance companies and mortgage lenders require industry certification that guarantees the building is capable of lasting for hundreds of years."
Certification of ModCell panels is essential, but scaling up production is also a necessary part of the research project, ensuring that the technology is priced at an accessible level for the domestic construction market.
Craig White of White Design, the architects behind Balehaus, said: "For Balehaus the panels were made locally, by hand. We’re going to be exploring opportunities for mass-production of these panels, making them available in far larger quantities, reducing costs and ensuring a sufficient supply for the widespread development of domestic straw bale dwellings."
The research is being carried out by the University of Bath’s Department of Architecture & Civil Engineering in collaboration with ModCell, architectural practice White Design Associates, Integral Engineering and Dutch company BB-Architecten.