This European Standard (all parts) covers the requirements for insulating glass units. The main intended uses of the insulating glass units are installations in windows, doors, curtain walling, structural sealant glazing, roofs and partitions. The achievement of the requirements of this standard indicates that insulating glass units fulfil the needs for intended use and ensures by means of the evaluation of conformity to this standard that, visual, energetic, acoustic, safety parameters do not change significantly over time. In cases where there is no protection against direct ultra-violet radiation or permanent shear load at the edges, as in structural sealant glazing systems, it is essential to follow additional European technical specifications (see EN 15434 and EN 13022-1). Insulating glass units that are intended for artistic purposes (e. g. lead glass or fused glass) are excluded from the scope of this standard. Glass/plastics composites are under the scope as long as the surface of contact with sealants is a glass component. NOTE For glass products with electrical wiring or connections for, e. g. alarm or heating purposes, other directives, e. g. Low Voltage Directive, may apply. This European Standard gives definitions for insulating glass units and covers the rules for the system description, the optical and visual quality and the dimensional tolerances thereof and describes the substitution rules within an existing system description. It also provides informative guidance for the installation of insulating glass units in windows or facades.