Straw bales are the bricks sustainable architecture is made of. Austria has gained leadership in Europe as far as straw bale building is concerned, not least because of many successful projects of “Building of Tomorrow”. Research has already shown the high potential of straw as a building and insulating material. Exemplary buildings can be erected using this regionally available renewable resource, not only in terms of CO2 savings and other ecological aspects, but also technically. Thus, the central goal of the project Stroh-Cert was to further the dissemination of straw bale building and to overcome obstacles towards market introduction. This goal was reached by certifying technically sound and standardized straw bales, by developing a concept for logistics, and by defining quality management. Accompanying dissemination measures were undertaken on conferences, trade fairs, and on the platform www.nawaro.com. Pilot projects for the demonstration of straw bale insulated buildings are underway.
Certification of straw bales as an insulating material:
Official acknowledgement of straw as an insulating material requires its approval via a certification process. In this project, the Austrian Technical Certification (ÖTZ) for straw bales was processed. With the certificate, disadvantages of straw bales regarding building authority issueswill be remarkably reduced. Through the certification straw will also qualify as building product to be considered in material catalogues for planners and national funding schemes.
Development of an efficient logistic concept for straw bales:
Straw, like other seasonal agricultural products, can be produced only within a relatively short period of time (June to August). Building materials, however, are needed all year long. Appropriate logistics coordinating production and delivery is therefore an essential requirement. A logistics concept was developed in close cooperation with commercial partners from straw and building industry and logistics. In developing this concept, existing availability of straw and capacities for transport, storage and production were considered.
Development of a quality management system for straw bales:
Quality management of products based on renewable materials is a challenging task in general due to the natural variability of these materials. Thus, a quality management system for the whole production and delivery process was developed. Furthermore straw is a totally new material to the building industry as well. As a consequence, methods and tools for quality control were checked for their suitability and developed further. All procedural instructions were compiled in detail in a quality handbook so that quality assurance can be guaranteed throughout the whole production and delivery process. Continuous documentation and traceability are as well important aspects of the quality management system.
Authors: R. Wimmer, H. Hohensinner, S. Eikemeier