Straw bales are building blocks of sustainable architecture. Austria has achieved thematic leadership in straw construction in Europe through numerous successfully implemented projects, including those from the “Building of Tomorrow” programme line. Previous research results have already shown the potential of straw as a building and insulation material. Not only in terms of CO2 savings and other ecological aspects, but also buildings that are exemplary in terms of building physics can be constructed with this regional renewable raw material. The central goal of the Stroh-Cert project was therefore to promote the spread of straw construction and to remove current hurdles on the way to market introduction. This goal was achieved by certifying technically sound and standardised bales as insulation material, developing a logistics concept and defining quality management. Accompanying this, the results were disseminated at trade fairs and conferences as well as on the internet platform www.nawaro.com; pilot projects for the demonstration of straw bale insulated buildings were started or initiated.
Certification of straw bales as insulation material
In order to establish straw bales as an officially recognised insulating material, the approval procedure for an Austrian Technical Approval (ÖTZ) was carried out. With this approval, disadvantages in matters concerning building authorities and subsidies are significantly reduced. The certification also enables further measures such as the inclusion as an eligible insulation material in housing subsidies and the entry in calculation programmes for planning and executing companies.
Development of an integrated logistics concept for insulation straw bales
As a seasonal agricultural product, straw, like other renewable resources, can only be produced within a short period of time (end of June to end of August). Insulation materials, however, are needed all year round. This requires a logistics model that encompasses all production and distribution steps and coordinates them seamlessly. In cooperation with economic partners from the straw utilisation, construction and logistics sectors, a logistics concept was developed that builds on regional straw availability and existing capacities for transport, storage and processing.
Development of a quality management system for insulation straw bales
The quality assurance of products made from renewable raw materials is a great challenge due to the natural variability. Therefore, a quality management system was developed for the entire production process. Since straw is a new insulating material for the building industry, the measuring methods and equipment had to be tested for their suitability and further developed. All testing and procedural instructions were prepared in detail in a quality manual so that a uniform quality management can be carried out during the entire production process. Continuous documentation and traceability of quality assurance are essential components.
Authors: R. Wimmer; Hannes Hohensinner; Rudolf Bintinger; Stefan Prokupek; Sören Eikemeier; Magdalena Burghardt; Chaipipat Pokpong
