Thermal insulation materials based on natural fibres are some of the promising materials that are currently emerging on the
construction market. These materials are important especially in terms of sustainable development, since they utilise renewable
raw material resources or secondary materials and their production does not consume too much energy. However, a problem with
these materials is the rather different behaviour during heat and moisture transport compared with conventional insulation, which
is made from synthetic (foam polystyrene) or inorganic (mineral wool) materials. The paper presents the results of a practical
investigation into the process of heat transfer through the structure of thermal insulation materials based on natural fibres.