What is straw? With cereal plants, only the grain and its casing are used for food production. Straw is a byproduct. In terms of weight, half of the crops of rice, oats, barley, rye, and wheat are straw. Straw can be stored in bales, which are bundles held tightly together with wire or twine. Bales come in many shapes, depending on the baler used. Rectangular bales are used most often for building.
Straw provides a very good insulation, resulting in minimal heating requirements. Additionally, straw has excellent sound insulation due to its relatively high mass.
There are two main ways to build with bales. In load-bearing structures the straw bales are structural and support the weight of the roof. This is the original way of building with straw and is also called the Nebraska method, referring to the Nebraskan settlers in the United States. The infill method, also known as timber frame method, is the other traditional way of building with straw. Here the straw is used as insulation in a structure of steel, wood or other structural materials. Hybrid methods combine both techniques and are used especially where lots of glazing is required on a wall. Nowadays prefabricated timber and straw panels are being used more often. These panels are already fabricated before arriving at the building site; making the production more efficient and independent of weather conditions. The panels are usually brought to the building site with a crane and can be assembled very rapidly.
Sutton, A., et al. (2011). Straw Bale, An introduction to low impact building materials. Great Brittain, University of Bath. Retrieved from: https://www.bre.co.uk/filelibrary/pdf/projects/low_impact_materials/IP15_11.pdf
Would you like to read more about the project ‘Straw as insulation material in a sports hall’? Click here!
Would you like to read more about straw farming in the Netherlands? Click here!