This European Standard specifies the requirements for factory made wood fibre (WF) products, with or without facings or coatings, which are used for the thermal insulation of buildings1). The products are manufactured in the form of rolls, batts, felts, boards or slabs. Products covered by this standard are also used in prefabricated thermal insulation systems and composite panels; the performance of systems incorporating these products is not covered. This standard describes product characteristics and includes procedures for testing, evaluation of conformity, marking and labelling. This standard does not specify the required level of a given property to be achieved by a product to demonstrate fitness for purpose in a particular application. The classes and levels required for a given application are to be found in regulations or non-conflicting standards. Products with a declared thermal resistance lower than 0,20 m2K/W or a declared thermal conductivity greater than 0,070 W/(mK) at 10 °C are not covered by this standard. This standard does not cover in situ insulation products and products intended to be used for the insulation of building equipment and industrial installations.