This document covers factory-made reflective insulation (RI) products intended for use as thermal and acoustic insulation of buildings. The products are manufactured in the form of rolls or boards. They are made from low emissive film(s) and infrared semi-transparent material layer(s) or air cavities. This document describes the methods and criteria for assessing the performance of factory-made reflective insulation products in relation to essential product characteristics and includes the procedures for assessment and verification of the constancy of performance. Reflective insulation products require specific setup instruction(s) depending on their level of compressibility. This document 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 levels required for a given application are to be found in regulations or non-conflicting standards. This document does not cover: products intended to be used for the insulation of building equipment and industrial installations; products made of mineral wool, polystyrene or polyurethane foams (not inclusive) faced with aluminium or metalized foil on one or both external surfaces (which are already covered by a corresponding harmonized European product standard); membranes used as vapour control layer (VCL) or vapour-permeable roof or wall underlay (which are already covered by a specific harmonized European product standard).