This international standard specifies the building maintenance unit?s terms and definitions, types and main parameters, general technical requirements, structure, stability and mechanical design calculation of equipment, suspended platform, hoist, suspension rig, rail track, electrical system and control system, test method, inspection rule, sign, attached files, etc. This standard includes the design and calculation of rail track and its support system of BMU, the relevant load regulation applied to the building structure by the wheel load of BMU, and the safety requirements of the building structure for the installation of BMU. This standard deals with significant hazards pertinent to BMU. This standard specifies appropriate technical measures to eliminate or reduce risks arising from the significant hazards. The BMU concerned and the extent to which hazards are covered shall be indicated in the scope of this standard.