This draft European Standard specifies the requirements for factory made calcium silicate products with or without lamination or coating which are used for the thermal insulation of buildings. Calcium silicate products have also the capability to regulate air moisture in building rooms, which means to absorb moisture from the air and opposite to give the moisture back to the room due to the capillarity of the product. Calcium silicate insulation material comprising hydrated calcium silicate, normally reinforced by incorporated fibres. The main crystal phases are Xonotlite, Tobermorite with or without Wollastonite. The products are manufactured in the form of boards, segments and prefabricated ware. This draft European Standard describes product characteristics and includes procedures for testing, evaluation of conformity, marking and labelling. This draft European Standard does not specify the required level or class of a given property that shall be achieved by a product to demonstrate fitness for purpose in a particular application. The levels required for a given application can be found in regulations and invitations to tender. This draft European Standard is not valid for products with declared thermal resistance lower than 0,13 m2 K/W or a declared thermal conductivity greater than 0,075 W/(mK) at 10 °C. This draft European Standard does not cover aerated concrete, autoclaved aerated concrete, mineral foam insulating products and sand-lime bricks as well as in situ insulation products and products intended to be used for the insulation of the building equipment and industrial installations.