In modern information society, data centres are the control and storage centres for the electronic data exchange. The ever-growing performance requirements for data centres as well as the unlimited growth of their energy demand call for approved technical specifications that enable the planner and the operator to plan, expand and operate a data centre according to the state of the art in a future-proof manner. This includes requirements for the availability of the services of the data centre, its energy efficiency and economic aspects, amongst others. Of cause there are quite a few standards for the components and subsystems used in data centres (for example, for uninterrupted power supply), a standard suitable for the European market for the design, planning, procurement, integration, installations, operation and maintenance of facilities and infrastructures within data centres has so far been missing. Upon German request CENELEC/TC 215 "Electrotechnical aspects of telecommunication equipment" decided to prepare the series of the European Standards EN 50600. The primary function of a data centre is usually the accommodation of a large number of computing and communication devices which effect the design, operation and physical safety. Most data centres can demand special safety requirements. Therefore the planning of a data centre by the planner and the various technical disciplines supporting him/her during planning and execution of the construction of the data centre, such as electrical engineering, machine technology, safety, etcetera, in collaboration with IT and telecommunication staff, network experts, the facility manager, the IT end user and all other employees involved. Part 2-1 contains the general requirements and recommendations for the building construction of data centres as well as the related aspects, without giving detailed design specifications, however. This also includes aspects regarding site selection (position and its evaluation, existing infrastructure) and site configuration. Part 2-2 contains detailed requirements and recommendations for power supply and power distribution in data centres. Thereby, the dimensioning of the corresponding systems, suitable availability classes and their physical safety. Three granularity levels containing the measurement points where the power consumption of the electrical devices and infrastructures of a data centre shall be measured, are defined with regard energy efficiency qualification. These standards have been prepared under Mandate M/462 "Standardisation in the field of ICT to enable efficient energy use in fixed and mobile information and communication networks" given to CENELEC by the European Commission and the European Free Trade Association. The responsible committee is Joint Subcommittee DKE/GUK 715.3 "Informationstechnische Verkabelung von Gebäudekomplexen" ("Customer premises cabling") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.