This European Standard: a) details the issues to be addressed in a business risk and operating cost analysis enabling application of an appropriate classification of the data centre; b) defines the common aspects of data centres including terminology, parameters and reference models (functional elements and their accommodation) addressing both the size and complexity of their intended purpose; c) describes general aspects of the facilities and infrastructures required to support effective operation of telecommunications within data centres; d) specifies a classification system, based upon the key criteria of “availability”, “security” and “energy-efficiency” over the planned lifetime of the data centre, for the provision of effective facilities and infrastructure; e) describes the general design principles for data centres upon which the requirements of the EN 50600 series are based including symbols, labels, coding in drawings, quality assurance and education.