This paper seeks to discuss the possibility of developing insulation materials for the construction sector made of non-industrial crop wastes and natural binders. Three different crop wastes widely available in Spain, namely barley straw, corn pith and rice husk, are used in the production of experimental insulation panels. Their thermal behaviour, equilibrium moisture content and water vapour permeability are assessed in order to determine their suitability as a construction insulation material. Results show that crop wastes can perform adequately as insulation materials with any or little manipulation. They also reflect how the choice of the crop waste affects the characteristics of the final products.