At the end of 2003 the KNX standard CENELEC (European Committee of Electrotechnical Standardization of the Home and Building Electronic Systems of the EN 50090 series approved as part of the standard. Also KNX Standard CEN (EN 13321-1 For the media and the protocol is approved by EN 13321-2 KNXnet / IP). At the end, the KNX is certified as a world standard (ISO / IEC 14543-3-1 to 7). In May 2013 KNX technology was approved as the Chinese standard (GB / T 20965). ANSI / ASHRAE has been approved by the United States as the 135th.